So, I heli-coiled the z1 cam caps fucked threads last night.
Went well. Engine is fixed. Really glad I didn’t have to take head off and take to Mar auto. I loosened and re-tightened all 16 bolts. All tightened down well. Hopefully no holes blow out again. Gotta love old shitty bikes and high-lift cams.

So, now I have about 8 or 9 of 16 holes heli-coiled.

My method of installing heli-coils is below: (all points open for debate)

• buy new pep boys thread repair kit – m6 / 1
• buy some blue loctite
• if not taking engine apart tape shit off real well
• drill out hole on super low speed with motor oil on drill bit
• use thread repair kit to re-tap hole to bigger size. Oil on tap
• while re-tapping hole, turn in 1 full turn. Then back out half turn every full turn
• while re-tapping hole, completely remove tap every 3 full turns to clean debris from tap inner catch area
• once hole is re-tapped and smooth, clean out any debris and oil
• put heli-coil in with a small drop of blue loctite on outer side of heli-coil
• make sure bolt goes into heli-coil smoothly
• I would not recommend using any loctite on the bolts that go in and out the cam-cap holes as they need to be serviceable, regardless of if any of the holes are heli’d or not.
• Larry Cavanaugh, the kz cylinder head guy, recommended keeping the threads on the bolts that go down into the cam caps holes oiled or greased. He said this to me in one of our emails when he ported my head and fixed a couple fucked holes.
• Specifically Larry said: Make sure you oil the cam tower dowel pins and the boss holes they go into in the caps when you install the cams. Oil the cam bolt threads too. Make sure the tapered end of the dowels point up toward the cap. The majority of stripped cam tower bolt holes result from the caps binding on those dowel pins
• Done. Go race people.

Here’s all the differences I found when swapping my CB550 cam for a CB650 cam. Follow the manual for the proper process of changing a cam.

Parts Needed:
79-82 CB650 cam
79-82 Tach drive
CB650 or CB750 Tachometer

The CB650 has a hy-vo cam chain so the cam sprocket will NOT work with the CB550’s normal cam chain. The CB550 cam sprocket and sprocket bolts fit on the 650 cam.
CB650 (left) / CB550 (right)

The cam markings are very similiar between the two.
CB650 (left) / CB550 (right)

CB650 (top) / CB550 (bottom)

Notice the slighly different pitch for the tach drives.
CB650 (bottom) / CB550 (top)

Tach drive pitch is slightly different.
CB650 (right) / CB550 (left)

Review:
I’ve been running the 650 cam for a few weeks now and have also changed from the air box to Uni pod filters. The power difference is not crazy but it is a nice even increase. The most noticable is on the top end, the bike wants to continue pulling strong 80-100mph. Previously it was a slower acceleration in that range.

Previously, I used to use a rubber freeze plug which is the standard internet forum recommendation. However, day one of riding to Lake Superior my freeze plug blew out and my bike hemorrhaged oil 30 miles outside of Philly. Fuck using freeze plugs.

Here’s how to modify your starter to remove the weight, plug the engine case, and retain both mounts for the starter cover. This is my 1976 CB550 but this will also apply to the CB500 and other motors with a similiar starter setup.

Step 1: Remove and disassemble your starter. This starter was already dead so I didn’t ruin a good one.

Step 2: Make an aluminum plug to fit where the starter shaft went.

Step 3: Weld it

Step 4: Cut aluminum tubing the length of the starter body to keep the correct spacing. I used 6061 aluminum tubing 3/8″ OD, .277″ ID, .049″ wall thickness which I picked up from McMaster-Carr

Step 5: Reassemble

Step 6: Install

Step 7: Done. Looks stock but you’ve saved maybe 6ish lbs.

If anyone is interested in this mod but doesn’t have a welder, email me and I can do it for you. Also, if anyone is holding a finned starter cover hit me up, I’m trying to buy one. Castandsalvage@gmail.com

Mar automotive is an engine machine shop in Philadelphia. They specialize in cylinder head repair, and can do pretty much whatever you need done to your motor.

I’ve talked about Mar auto a handful of times on this site but I thought I’d give some more info.

Check them out online here:
MAR Website
MAR Instagram

I first learned about them 8 years ago when I was having an issue with my Honda S2000 car. A couple valves weren’t seating properly. Shit was all under warranty, I took it to the Honda dealer near airport, they took the head off and sent it to Mar. So I called Mar and asked questions about what was actually wrong with the s2000 head. They were friendly nice guys. So I said, hey, can I bring you a motorcycle head? 

Since then I’ve had 3 or 4 heads done by them and other numerous friends have also brought heads to them. They always do a great job and are super quick turnaround. They’re a 15 min drive up frankford ave. They open at 7am ish so it’s easy to go during the week.

I disassembled my cb650 motor the other day to replace the head gasket. Figured I’d bring the head to Mar to freshen it up.

When I was there picking up the head they showed me around. Explained how some of their tools work, and let me snap some pics.

The below pics show the tool they use to shave the surface of your head or cylinders to make sure its completely flat. They can set it to remove a hair… or as much as you want to shave it.

The below pic shows the different angles to the valve seat and he explained how far in they can be.

Below pic is their valve cutting tool to get it perfect. They also measure all your valves to make sure they’re not bent. And what I mean by that is, they could be bent a hair, that you wouldn’t be able to tell, but really, that hair is causing them not to seat properly.

Below pic, he showed me when the seat is recut, and the valve is cut, they pop-push it in to see if the indentation line of where its seating is indeed in the correct spot on the valve.

Below pic. After they get all the valves done, they have a pressure-suction tool which actually measures if there’s even a microscopic leak. Next pic shows the gauge to check each chamber. When he was showing me this tool, I asked if flipping the head over and filling the chamber with oil was a good test, and he semi-laughed and said yes… but not really. A legit tool like what they have is the real way to know.

While I was there he told me a story about how a guy brought a 4cyl, 16 valve motorcycle head to Philly cycle center, and asked for a rebuild. Philly cycle center quoted him $750 ish. The guy said maybe, and then continued calling other shops. Mar talked to him and basically said, our price is $300 ish based on the hours it’ll take on the spec sheet for 4 cylinders and 16 valves. Why was Philly cycle center so much more? Who the hell knows. All Mar does, all day, everyday is build engines, and normally more complex car engines, so I’m pretty sure working on a little motorcycle engine is a piece of cake for them.

If you need to replace a head gasket, or if your bike is smoking or running like shit, do yourself a favor and don’t fuck around trying to replace valve seals and do a valve-job on your own, in your basement… have the head done by experts like Mar.

Years ago when I first got my Kaw z1, the bike actually ran pretty good. I took the head off and brought it to them to have it checked out, and they told me all the valve guides were super loose and all the exhaust valves were bent. Damn, I was shocked. Point being… your head probably is shitty and you don’t fully realize it.

Best logo ever.

Below pic, cb650 head finished. Valves done. Shaved flat. New valve seals. Everything checked out. Head was done in under a week.

Cylinders got a fresh hone job.

1. Anti-seize is NOT recommended
“NGK spark plugs feature what is known as trivalent plating. This silver-or-chrome colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. The coating also acts as a release agent during spark plug removal. Anti-seize compound can act as a lubricant altering torque values up to 20 percent, increasing the risk of spark plug thread breakage.”

2. Selecting a Heat Range
“It is believed by many that the heat range measures spark temperature or intensity. This is incorrect as the heat range is actually a measurement of the plug’s ability to transfer heat away from the tip of the spark plug. One cannot change the temperature of how hot a fuel burns.

A hot spark plug has an insulator design that will be slower to draw heat away from the plug tip (thinner insulator mass), whereas a cold plug has an insulator design that will be faster to draw heat away from the plug tip (thicker insulator mass). For a spark plug to function properly it must have a tip temperature hot enough to invoke self-cleaning, while remaining cool enough to avoid pre-ignition.

For most vehicles, the factory recommended heat range is sufficient; however, on some modified or special-use engines, alternative heat ranges may be necessary.”

3. Torque
“Torque is critical in the plug’s ability to dissipate heat and perform properly. The spark plug holes must always be cleaned prior to installation; otherwise, you may be torquing against dirt or debris and the spark plug may actually end up under-torqued, even though your torque wrench says otherwise. Of course, you should only install spark plugs in a cool engine, because metal expands when it’s hot and installation may prove difficult.”

In the Clymer manual for the CB650 gave some interesting info regarding selecting a heat range depending on riding type and climate which I have not seen in other manuals:

D7EA – Cold weather climate
D8EA – Standard heat range
D9EA – Extended high-speed riding

Here’s how to decipher the spark plug codes. For example, I am running a D9EA:
D = 12mm thread ø
9 = Heat rating
E = 19mm thread reach
A = Firing end construction

1. Titleable motorcycles 300 cc’s or more last registered in another state are required to have a VIN verification from the Vermont personnel listed above.
2. All used motorcycles 500 cc’s or more being registered/titled in Vermont for the first time, regardless of model year are required to have a VIN verification from the Vermont personnel listed above.

Here are the steps to getting a Vermont plate and registration for a motorcycle. I’m sharing this info with the hope that it’ll help keep another old motorcycle on the road.

A photo posted by Cast & Salvage (@castandsalvage) on Feb 29, 2016 at 1:31pm PST

Here’s how I registered my KZ750:

DOCUMENTS:
1. Bill of Sale
2. Vermont Registration Form VD119
3. VIN Verification

STEPS:
1. Make a Bill of Sale to show proof a sale. This can be between any parties and does not need to be notarized.

2. Fill out VT Form VD119. I originally submitted my form without the VIN Verification and it was mailed back to me with the red markups.

• Motorcycle fee is $48
• Tax is 6% of the NADA good value.
• Write check for total amount payable to: Vermont Department of Motor Vehicles

3. Bring the motorcycle to an Auto Tag shop and have them complete a VIN Verification form. If you’re in PA you can use the PA MV-41 form or the VT form VT010.

5. Mail everything to:

Vermont DMV
120 State ST
Montpelier VT 05603

Turn around is 2-3 weeks and what you get back are VT plates and registration. You can then use that registration paperwork to apply for a PA title and registration.

If this has helped you out we could use your help to keep the COTT website going. Thanks in advance!

It’s time to take a good look at your cafe bike / chopper / bobber / enduro…

Riding old enduro bikes around in the woods and street is pretty awesome. It’s some of the most fun I’ve had since BMX.

My CT1-175 and IT250 are pretty loud. Chain saw loud. I assume most people assume I’m on an off road dirt bike, just like every other ghetto kid ripping around. I get it. Whenever I hear that 2 stroke noise I naturally assume the bike is an off road dirt bike and not street legal.

So, I started thinking about what it really means to make any motorcycle 100% street legal?

For example, yes, my CT1 is insured, and has PA title and registration, and I have lights. Bike is totally street legal right…? But if a cop pulled me over, could he still give me tickets for little things if he wanted to be a dick?

Items needed for a MC in PA to be truly street legal

• Motorcycle VIN needs to be the type: “dual-sport” or “street”. “Off-road” type VIN can’t be titled for street use.
  Read comment #5 and #6 here if you want more clarification.
• You must have a MC permit or license and insured.
• Must have a registration. Yes, Vermont is fine and legal.
• Must have inspection. Unless your plate is an “antique” plate?
• Must have a working horn.
• Must have a brake on each wheel.
• May have turn signals. Basically this means, you don’t need them and can hand signal.
  PA MC code: 175.146 sub section f2.
• Must have a speedo and odometer.
• Tires must be DOT and say DOT on them.
• Must have a headlight and tail light. Tail light or a light must illuminate the license plate.
• Must have at least 1 mirror
• Fuel system must be leakproof. So if your carbs leak, you could get a fine?
• Exhaust can’t be louder than 88 (decibel (A).
• Must have fender for each wheel.
• Must have a kick stand.
• License plate can’t hang loosely. Must be seen by 50ft from the rear. Can’t be obscured.

All of the above info is based on the PA motorcycle code. Link below:
PA motorcycle code

Just because it states you need everything in that list, I highly doubt any cop is checking certain things. For example; are they checking if you have a horn ha. 90% of the time cops don’t even care if your MC is inspected. Seriously, who the F gets their MC inspected. Are cops riding around with a decibel sound tester for your exhaust, ha. No.

Guarantee the cops don’t know the PA MC code off the top of their head anyway, so if you get pulled over be nice and play dumb. It’s worked for me; “Uh, I didn’t know my license plate couldn’t be hidden under my seat. Are you sure officer?” Ha.

Last – To reiterate from a previous post I made several months ago here… about if the cops can take your MC… In this article by NBC10, Lt. Stanford of the Philly police states twice; “Police can only confiscate a dirt bike under two conditions — if the operator doesn’t have a license or the bike is not registered.”

Comment and let me know if there’s anything big I’m forgetting, or if anything is blatantly wrong, which I’ll update in the list above. I’m not a lawyer so I’m reading the PA code and making the best sense of it that I can.

First off… Why do you care and what’s the deal?

On 2 stroke dirt bikes, there is a rubber seal on either side of the crankshaft. Over time these dry out.

The seal on the magneto side (left side) prevents air from getting into the combustion chamber. If the seal on this side goes bad, you’ll get air leaks. Your idle will hang and/or the bike will rev erratic randomly. Bike will run lean and trying to tune it will be pointless.

The seal on the clutch side (right side) prevents crankcase oil from getting into the combustion chamber. If the seal on this side goes bad, you’ll burn a ton of oil and eventually foul plugs and suck the crankcase dry of oil.

Ok.

Things you’ll need to change the crank seal which you most likely do not have or own:
– air compressor set up and air gun to loosen certain bolts for the first time in 30 years
– 26mm / 29mm / 30mm socket
– yamaha magneto puller tool

Magneto side crank seal

1. Use OEM yamaha seals. Get them from BikeBandit.com
2. Pull the cover off
3. Bolt will be a 19mm. Unless it’s recently been loosened at some point, absolutely no way you’re getting it off without an air compressor set at above 80psi.
4. Once that bolt is off, screw on the yamaha magneto puller tool
5. Tighten it on there and then start to use the 2 wrenches to pop the magneto off. If this is the first time your magneto is coming off, be prepared to feel like you’re going to strip threads, or break something. Every time that it’s the first time i’m blowing off a magneto that’s been stuck on there for 30 years, it’s blows off with a crazy loud noise. Shit is seriously scary.
6. Use an impact driver to get the stator screws out.
7. Then take a drywall screw and hammer it gently into the old seal. Only poke it through a tiny tiny bit. Then screw it in only until it grabs. Then use a hammer to pry, and pop out the old seal. Side note – if you can get the seal out with a pick instead of a drywall screw, do it. Good luck though.
8. Wipe everything dry with alcohol. Then, since this side is prone to air leaks, I use Black Gasket sealer on the outside of the seal. Never gotten air leaks by using this method.
9. Push the seal in gently. Tap it in gently if you have to. Also, once the seal is pushed all the way in, put a thin coating of gasket sealer around the outer edge. Someone once recommended this. Works for me. Again, gasket sealer is up for debate but I like it on things that are prone to air leaks.
10. Since it’s all apart, wipe the contact areas of the stator and magneto clean with a rag and alcohol.
11. You’re done this side. Reassemble. Important note – when you put the magneto back on make sure you tap it on super hard with a rubber mallet. It needs to sit all the way into the woodruff key and the bolt needs to be tight as shit or the woodruff key will sheer off.
12. Last note. These seals are directional. So put them in the right way which is little round spring facing into the combustion chamber. My images show it going in backwards, sorry. However. I put them in backwards in my IT and never had a problem … actually think it makes more sense to put them in backwards so the little spring can’t fall into the combustion chamber. I dunno, it’s your call. 

Clutch side crank seal

1. Pull the cover off
2. Undo the clutch spring bolts
3. Those 2 bolts I’m pointing to will definitely not come off unless you have an air compressor set up. Maybe if you have a clutch basket holder. Still they prob won’t come off.
4. Once you do get them off, it’s easy. Pull off the clutch, and pull off the primary gear. Take a photo to ensure proper reassembly if you need to before pulling shit all apart.
5. Popping the seal out on this side is the same as the other side you just did
6. Wipe everything clean with alcohol, and put this seal in dry. No gasket sealer.
7. Reassemble. Make sure you tighten those 2 big bolts back to the torque spec or at least make them tight as shit. Then… Drink a beer.

1. The brake stay and the donor one that was in the scrap bin with a matching OD.

2. Made my cuts as clean and straight as possible then squared them up on the disc sander.

3. Using the belt sander, I chamfered on all the mating edges and cleaned everything up for welding.

4. Using a v-block to clamp up the first side to tack it in place. V-block are really helpful with lining up round pieces. I left a 1/16″ gap between the pieces so that I could get the proper penetration with the weld.

To tack up the other side I clamped down both flat ends to the table so that they’re on the same plane.

Then using a piece of angle I clamped the joint so that everything lined up.

5. Completed the welds and cleaned them up with a handle file. I find this to be the best way to make the joint look seamless.

6. Finished and on the bike

…into this…

…then into this…

…and get one of these…

…then go rip around worry free.

Overview

If you purchase a vehicle that does not have a title, it can be a little tricky to get one. Fortunately, there is a legal loop-hole to eventually obtain one:

• Vermont will issue you a registration and license plate regardless of if you live in VT or bought the vehicle in VT. So, this is sufficient to drive around legally in any state.
• Once you have the VT registration, you can then transfer it into your state at an “auto tags” business, and apply for a title / registration in your state.
• The reason this works is because VT only titles vehicles 15 years and newer. So, for an old motorcycle or old car, there would be no VT title at all… so your state will recognize this, and will issue you a new title for your state. It’s a big loop hole, but it works.
• I’ve heard some states (such as NJ) can be a little finicky about transferring VT registrations into their state and applying for a title… but Pennsylvania obviously doesn’t care.

Steps to follow

1. When you buy your vehicle, make sure you get a bill of sale with the seller, and have it notarized. Here is an example bill-of-sale you can fill out and use. If the actual seller is weird and won’t fill it out with you, or go to the notary… just fill out the bill of sale as if a friend sold it to you, and go to the notary with a friend. A notary surely doesn’t care or know who the real seller is… or when you bought the vehicle.
2. After you have the bill of sale squared away, download and print out the Vermont Registration form and fill it out. FYI – Bikes over 300cc need the VIN certified by a cop, dmv, or auto inspection station to prove your vin matches up. Explanation is on page 2 of the VT registration paperwork. Section 7.
3. On the VT reg form… the fee for a motorcycle is $44. Plus tax. To calculate tax on the price of the vehicle, it’s 6% of your purchase price, or 6% of NADA “good” value. Whichever is higher. Let’s assume NADA value is higher than what you actually paid. So, if NADA “good” value is $800. You pay VT 6% sales tax based on that. $800 x .06 = $48. So total fee you pay VT would be $44 + $48 = $92 total. So, write VT a personal check for $92. Make check payable to “Vermont Department of Motor Vehicles”.
4. Ok. So, now you have the bill-of-sale and VT-registration forms both squared away. I like to print out a screenshot of the NADA good value. Also print out a photo of the motorcycle.
5. In an envelope, mail Vermont the: bill-of-sale / VT reg / personal check / pic of NADA value / pic of the VIN / if it’s a dirt bike don’t include a pic of the bike. Address to mail stuff to is: VT DMV 120 State St. Montpelier, VT 05602.
6. At this point – Make sure you get the bike insured.
7. Drink a beer. In about 10-20 business days, you’ll receive a Vermont license plate and temporary registration. Be pumped, you can ride the bike legally now! In about 10 more business days you’ll receive the actual VT registration paper. This can be renewed once a year if you want. But it makes sense to transfer it into your state.
8. Wait about a month, and then go to your local “auto tags” business (I’m in PA. Your state may call this something different or you need to go to a DMV?) The rest of the steps will assume you’re in PA.
9. When you get to the auto tags place, tell them you want to “transfer a VT registration into PA, and apply for a PA title and registration”. They’ll say “sounds good. Can we see your PA license, auto insurance, VT registration and title”. You will reply with; “VT only titles vehicles 15 years and newer, so there is no VT title. Look it up.” They’ll say; “oh. okay”.
10. The auto tags place will fill out the PA registration papers for you… applying for a new PA registration and title. They’ll give you a plate and temporary registration right there on the spot. Sweet.
11. In about 5 weeks you’ll get your real PA registration, and then in another 8 weeks you’ll get your real PA title! Obviously put this somewhere safe.
12. That’s all there is to it. Drink a beer. You just beat the system using a legal loophole.

We hope this helps you get your motorcycle back on the road. If you can help us out we would appreciate it!

I found an NOS piston and rings on Ebay for $130 which is expensive but it was the only option. My head is a stock bore of 60mm and Wiseco and Prox do not make an piston for it. There are plently of new pistons for the 1977+ models which are not compatiable because of the wrist pin location from the top of the piston. So, I was stuck having to buy expensive NOS. Came in some cool packaging though.

This is the best example I was able to find of the comparison of early vs late dt175 pistons. I might be completely wrong about this but there’s so little well documented info out there between all these different year DT’s.

Checked ring gap at .4mm which is within spec.

These rings have locating pins on the piston so and they have to be installed with the ‘V’ to accomodate that pin.

Lubed everything up with 2 stroke oil before assembling. The wrist pin and bearing I took off were worn out so I got new ones along with new clips. Another $40 in parts. After ordering from BikeBandit I found that Yamaha has a site: http://www.yamahapartshouse.com were you can get all the same OEM parts and it’s a little cheaper.

I used Hylomar to prep the copper head gasket.

Assembling a single piston 2 stroke top ends is dumb easy compared to 4 strokes. Torqued the head to 15 ft lbs.

I had a few different plans for making the 21″ MR125 Honda Elsinore front wheel fit my stock forks. The main issue is the brake sits 1/4″ away from the stock fork stop. To keep it simple, I decided to just extend the stop to fit into the brake.

Came out pretty nice. I’m a little out of practice with my aluminum welding so Rick did it for me quick. With a little file work it’ll look stock.

Next: Electric simplification

• Read about rebuild Part 3
• Read about rebuild Part 2
• Read about rebuild Part 1

Well… the 450 is finished and it runs. Video at bottom.

I’ve riden it about 10 miles so far. Haven’t gone over 5K rpm yet, but it feels super responsive and eager to rev. It’s not dialed in yet though… still have to fine-tune it.

Below pic…
Threw the engine back into the frame.
– put in a new clutch
– installed the Pamco electronic ignition

Damn that shit looks good!

Not a 500… High compression 550cc – boom

Electric starters are lame. Plug that shit. Auto-zone. $3

New (used) OEM mufflers.
I punched them out to make them straight-through instead of chambers. Should flow decent now which is something the high-compression engine is going to need.

Sounds way “punchier” compared to before.

This is a 1979 CB750 frame that came to our shop with the rear already chopped off and needing the rear loop fabricated. Here’s the steps to make that happen:

1. Clean up the frame and remove the extra metal that was used for bulking up the oem pinched frame ends using a chisel and folding it in on itself until it falls out.

2. Measure the inside diameter (ID), outside diameter (OD), and center-to-center width. You’ll need this for the layout of the frame hoop and picking out tubing.

3. Cut 2″ pieces from tubing with the same OD as the ID of the frame. These will be used as slugs between the frame and the new section which helps align and strength the joint. I missed getting a photo of this mocked up in the frame but you get the concept.

4. Using the appropriate die, make a 180 degree bend in the same OD tubing as the frame.

5. Layout out your cuts to fit the frame width and tack it together to check fitment. All butt joints should be beveled to prep for welding.

6. Weld!

7. Clean up the welds using whatever method you prefer. I like to use a flap wheel to do the majority of the work while leaving a small amount proud of the tubing OD to be finished off with hand files in order to get seamless, smooth finish leaving no indication of a joint.

Get in touch with us at Cast & Salvage if you’re looking to get a rear hoop or any other frame modification done on your project bike. We love this stuff.

• Read about rebuild Part 1

Ok… So, I had a couple different machine shops do a couple different things for me.

First machine shop:

Mar Automotive
4345 Orchard Street,
Philadelphia, PA 19124
(215) 288-7320

They’ve done cylinder head stuff for me in the past:
– they did a valve job on my S2000 like 5 years ago
– they did a valve job on my cb650 like 3 years ago

So, I vouch for them. They’re fast, cheap, and quality.
All they do is cylinder heads and valve trains. All day long every day. That’s it.

What they did:

– 3-angle valve job on the 500t head.
– Blasted it clean.
– Skimmed the deck to make sure it’s flat.

A 3-angle valve job is the best way to get your valves to seat. Think of it this way. If you’re looking to keep costs down… lap the valves yourself and you’ll probably be okay.

I talked to a couple people and they convinced me to get a full on valve job done instead of lapping.

3-angle valve job means, the valve seat has literally 3 angles. Normally 30˚ / 45˚ / 60˚. They actually cut new angles to ensure everything is seating correctly. It’s more accurate than lapping.

Price:

– $100 and it was done in 1 day.

Below pic: Damn that shit looks good.

Freshly cut seats.

Valves cleaned up more.

Pretty sure they painted the head silver after blasting it clean.

Second machine shop:

Powerseal USA
337 Coldstream Road,
Phoenixville, PA 19460
(484) 921-5121

I heard this place does a good job with boring cylinders and milling decks and stuff of that nature. I’ve never used them before.

They’re a bit out of the way being 30 miles away. Fuck it. Figured I’d give them a go.

The guy was cool and said he’s built cb450 engines before. Works for me…

What they did:

– Bore the cylinders out from a 70mm to a 74mm.
– Mill .010″ from the top of the cylinders (raise compression 1/4 point)
– Cleaned everything and honed the fresh cylinders.

Price:

– $180 and it was done in a week.

Below Pic: These are the pistons sitting in the cylinders.

I found a pair of Todd Henning 11.5 compression race pistons on eBay for a price I could live with.
My 500t engine is now a 550cc. Badass. And in a cb450… extra badass.

See how they are sitting just below the deck. If I actually had a cb450, they would sit flush, and would actually yield 11.5 to 1 compression.

After talking to a few people, I finally realized the 500t engine is different with it’s placement of the wrist-pin on the piston. Ahhhhh.

So…
long story short, if you put 450 pistons in a 500t, they yield lower compression because they sit below deck height as seen in the below pic.

So…
These 11.5 pistons really are going to yield 10.5 compression in my engine. This is why I milled the cylinders .010″, to raise compression again and bring them closer to the deck height.

So…
I should have somewhere around 10.7 compression in this engine. Which should be fucking awesome considering stock compression is 8.5 … hahah. Looks like I’m always running 93 octane! Fuck it.

The pistons domes have cut-outs for the valves. Cool.

Another thing to note. You can’t put an OEM cb450 piston in a 500t. It will hit the crank because the piston skirts are longer. All cb450 race pistons made by people like Henning / Hanson / M3 / Charlie Place … all shave down the skirt… so their 450 race pistons all fit 500t engines. Just account for the lower deck height.

For example; Charlie Place cb450 race piston kit is 10.1 compression… So in a 500t this will yield 9.1 because the piston will be sitting lower in the cylinders due to the wrist-pin placement.

Make sense? Okay.

Regardless, I wanted to show the basics of lapping valves.
Figured it’d be good to show a general overview.

I made a quick video. I’m sick today… Hear me sniffling?

This ring below is the valve seat.

You can see below, the valve sits in the combustion chamber and needs to sit as closely / tightly as possible to the ring on the combustion chamber. Over time I guess the seat gets worn and can start leaking which causes lower compression and a weaker engine.

Another view below to see how the angle of the valve sits on the angle of the ring in the combustion chamber. This is really what is happening. You want the angle of the valve to perfectly match the angle of the ring in the combustion chamber.

This is the grinding material and lap tool.

See how the suction cup thing holds the valve.

cb450 and cb500t have no valve springs.
They have a torsion bar set up.

Let’s take a look at how exactly the torsion bar works. It’s pretty cool.

Pic 1 –
The engines are double overhead cam which means there is a separate cam lobe for each valve. Tuners and people looking to make power like DOHC because you can fine tune the cam duration and lift for hitting each valve. It’s easier to make more power with DOHC compared to SOHC (single cam). Thats probably a general statement, but whatever.

Pic 2 –
Here is the torsion bar assembly all together. Again… no springs anywhere. It took me some time to figure out exactly what’s happening. If there is no actual spring, how does the bar spring back to close the valve?

Pic 3 –
We can see in the below pic it’s the same as Pic 2, except taken apart.

The way the bar springs back to close the valve isn’t by springing… The inner piece of metal actual twists. Yea… twists.
Pretty crazy huh. It’d be like taking a solid piece of steel and placing so much pressure on it, you twist it. ha.

The bar is fixed on the left side, and the right side, it fits onto the outer sleeve which put pressure on it when the valve opens, and literally twists that inner bar to close the valve.

And we can see in the bottom right of the pic… the claw looking thing is what’s attached to the valve, so when the valve gets hit open by the cam follower, this claw thing is what pushes back on the outer sleeve of the torsion bar, to then put pressure on the inner bar to twist itself.

Pic 4 –
Below pic may help clear it all up.

Green arrow is the camshaft. This spins and hits the Orange arrow which is the cam follower.

Orange arrow opens the valve down into the combustion chamber.

Red arrow is the claw which is ultimately attached to the torsion bar which twists itself to push the valve back in the closed position.

Pic 5 –
There are two torsion bars. A and B.
Apparently, over time… the torsion bars can get soft or tired and lead to valve float. I talked to a couple old school Honda cb450 race builders and they suggested a couple things.

Find NOS (new old stock) torsion bars.
Or, test mine with a inch-lb torque wrench. Apply pressure on the torsion bar to see if it’s within spec. 80in’lb is stock. Anything under 60in-lb needs to be replaced.

Apparently, it’s easy to find NOS side B torsion bars. I found 2 of them on eBay, so I’m good on that side! I can’t seem to find side A NOS, so I bought another set from a low mileage 500t, and hopefully when I test them, they’ll be close to 80in-lb tension. Or… find another set and test them.

The reason the torsion bar tension is so critical is because you don’t want to get valve float which is bad. You’ll get surging at high-rpm or burn up a valve, or possibly valve could hit a piston. Apparently the stock torsion bars are super strong and reliable, but over 40 years they need to be replaced. Stock torsion bars were used in race engines up to pretty high RPM’s. If I could find NOS for both sides I’d consider running a race cam, but for now… I’m not sure.

This is a damn cool engine. Dare I say one of Hondas more unique engines? The only other Honda engine that torsion bars came in would be the v12 formula f1 race engine! Which revved high as shit I’m sure. Badass!

Here is the advice the old school cb450 engine builders gave me:
– def replace valve seals
– try and find NOS torsion bars or test tension. under 60in-lb is no good
– you can bore the cylinder wall to 74mm without worry

More about boring and pistons a little bit later.

Stay tuned.

Below pic is a fully disassembled view of the torsion bar assembly.
See… no springs anywhere.
The long skinny bar actually twists to create a “spring-like” motion to open / close the valve.

As you can see in the below picture, my cb450 valves were all sorts of f’ed up.

We determined that the piston must have burned up a hole in itself and the aluminum burned onto the valves? I guess? I could not get the shit off no matter what I tried.

Remember this is an extra head I got on eBay so I really didn’t know the condition.

So, Ricky had a tip to get the shit off the valves. He suggested muriatic acid to burn the aluminum off of the steel valves. It def worked great. Thanks Rick. Took a while and pretty sure I have cancer now from the fumes, but the valves seriously look like mint NOS valves after a quick run on the wire wheel.

They should lap in great now.

Let me recap what I’m doing…
I have a 73 cb450 that I put a 75 cb500t engine into last year. (Hence cb475)
Read about that HERE.

The head gasket leaks… so I’m going to tear the engine apart and rebuild the damn thing into a super hybrid engine. (Hence supersport)

• I’m going to put a 450 head on the 500t cylinders because it has a smaller combustion area, so it will yield higher compression. I bought a used 450 head on ebay.
• Also going to put 10.6 high compression pistons in it from Charlie’s Place.
• And going to also replace the valves, rocker arms and cams… which you’ll see why. Keep reading…

Get the cams out.

In case you didn’t know… The cb450 / 500t have torsion bars instead of valve springs. Ducati can suck it. Honda did it first. So… no valve springs. The torsion bar is a weird concept. It’s wound with a spring, so an arm hits the valve open and then the bar returns the valve closed. Apparently this reduced the risk of valve float which is when, at high rpm, the valve doesn’t close fast enough and the valve never closes. When valve float occurs, you can burn up a valve and/or feel surging at high rpm.

The rocker arms are worn pretty bad. See how they “dish inward”. Bad shit. Read this. Apparently this is common on 450 & 500t engines. The cam hits the rocker arm, and then the rocker arm hits the valve to open it. If it’s worn real shitty like the below picture, you can’t adjust the valves to spec. I’m going to get new ones from M3 racing which are harder. Also, it looks like a piece of the rocker arm broke off and damaged the cams a tiny bit from bouncing around.

Valves are shitty too and where they seat in the head isn’t the best. I found new NOS valves on ebay. Going to buy them, and lap them in. Valves guides seem okay… I think.

Once you get all the shit out, you can access the valve seals right above the guides. Going to be replacing these guys later.

Cams are fucked like I said earlier. They’re scored to the point where I’m going to look for another set of good condition used ones, or buy new high-lift cams from M3 racing. Not sure if I want to get high lift cams though…

All done.

Empty head now.

Time to figure out what I want to order new, and what I want to try and pull from my 500t head and use the best parts from both.

Our friend Bill Becker was kind enough to coach me through this, and let me use his tools.
Thanks again Bill!

1)
Get all new spokes and nipples from Buchanan Spokes in California. Mail them an inner and an outer, and they’ll match it. I went with stainless steel. Package comes with oil. Oil all the spoke threads.

2)
Lay the wheel out. Get the rim level with the hub.

3)
Start with the inner spokes. From hub, it’s every other hole. On rim, it’s every 4th hole. Put the nipple on right when you put the spoke in. Only tighten a couple turns, just so nipple holds on.

4)
First side inner spokes done.

5)
Flip wheel over.
Do other side of inner spokes. Same as step 3, except, put nipples on last after all this sides inner spokes are on.

6)
Start doing outer spokes now. Lay them out on top of inner spokes. Don’t try and put them in the hole until all this side outer spokes are placed in. Then find the holes and put nipples on.

7)
Flip wheel over.
Do the same as step 6 on this side now.

8)
Put the wheel on a truing stand, and use a screwdriver to seat all the nipples to where the threads end in the next pic.

9)
Now hand tighten all the nipples until they bottom out with a screwdriver.

10)
Get the right size spoke key. Now start tightening all the spokes tight. But not too tight yet.

11)
– tighten all spokes firmly now
– adjust concentricity first (remove hop from wheel)
– adjust side play second
– when wheel is straight you want all spokes to be tight enough that when you hit them with a wrench it sounds like a note on a piano.

Bill Becker working on his cz125. He’s doing a full restoration on it.

Bill when he was in his mid 20’s riding around on the cz125.

FYI –
Bill is available for hire to do any custom wheel building if anyone is in need of it.
His email is below:
wbecker212@gmail.com

Check out 2 of Bill’s bikes on BikeEXIF:
– Aermacchi Sprint
– Norton Commando MKIII

1) Photoshop it out

2) Template it out

3) Plan it out

4) Draw it out

5) Cut it out

6) Check it out