79-80 cb650 actually have pretty good stock-oem carbs IMO: 29mm bore, mechanical slide and accelerator pump. However, if yours are getting shitty and want a nice upgrade, brand new keihin crs29 smoothbore race carbs are the way to go. 

If you have the shitty 81-82 constant velocity carbs, bummer for you. Def upgrade to the keihin crs.

Benefits of keihin crs smoothbore carbs

• Brand new. Still made today. Every and any part is available still
• Every single circuit is tunable to a fine degree 
• They’re not too difficult to tune
• You’ll prob get a few horsepower assuming you tune them properly
• Choke is on the carb body so no more shitty cb650 pull choke near handlebars
• Nothing beats brand spanking new carbs… Best upgrade for any bike IMO

Keihin crs29 jetting for cb650

• 115 main jet
• 220 main air jet
• 68 slow jet
• yy6 needle – middle
• Air screw 1 turn out 

If you have a 4-1 exhaust, and you’re basically at sea level, above is the jetting I recommend to get you in the ballpark… to then fine tune.

Things to note

1. Intake spigots need to match up: if you have 79-80 you’ll want Keihin intake spigot number 020-024 (below pic) for a Suzuki gs850. Needs to be long enough to clear the petcock as seen in below photo. Also need to shave off 1mm from the end that sits into the intake boot so it seals properly.
2. Pod filters won’t really fit. They hit the frame on cylinders 1 and 4. So I’m running the velocity stacks that come with the carbs.
3. You’ll need a different “pull” throttle cable. Use the “push” from the CB650, and then buy a “pull” from a 78 Kawasaki kz1000. KZ cable is slightly longer looking but the cable/housing ratio is what you want.
4. Where the cables thread into the carb holder…You’ll need to bend the tabs up and to the left a hair, so the cables clear the frame of the motorcycle. Seen in below pic.
5. Get a pair of new rubber intake boots. Might as well, right.

Conclusion

Yea, if you have a 4cyl jap bike… These are the best carbs you can pick up, hands down. I also have a set on a 74 Kawasaki z1 and I love them. Don’t put carbs on your bike that are too big bore. Some people upgrade to the Mikuni RS34, which are too big. For a 4cyl, I love the Keihin CRS, and for a twin or single cylinder, I like the Mikuni VM.

These carbs will work great on any 70s Honda CB 500, 550, 650, 750 4cyl.

However, on 500, 550, you should run the keihin crs26. Slightly smaller bore will work better.

Photos by Alex and myself.

Day 1:
Met up at Ben’s garage and then raced out of the city to make it to the Red Rabbit drive-in just before it closed. Setup camp at our favorite Duncannon camp spot from previous COTT trips along the Susquehanna River. Route 322 through Duncannon is basically a trucker spot and has more strip clubs than you’d think. We tried them all out and ended by getting kicked out of the last stop because somebody couldn’t keep there hands to themselves. Ended the night by the fire with Ed drinking my whiskey and becoming agro Dad… then made the post below which he didn’t remember the next morning. haha dick.

Day 2:
Woke up on the Susquehanna and had the first river bath of the vacation. Packed up and headed West on 274 towards Raystown Lake. Only did 100 miles but it took us all day which was fine when there’s no real plan. Went through Orbisonia, PA and checked out the old trolley cars and steam trains from the Industrial Revolution. Finally made it to Raystown and parked the bikes in the woods and went on foot searching for a cliff jumping spot Ed knew of. Ed showed everyone up by diving off the 40′ cliff.

Day 3:
Woke up on Raystown Lake. Andrew and Devyn arrived overnight and somehow didn’t wake anybody. Devyn slept in the tent without poles haha. Headed out to the local diner for food and to figure-out the days plan. Decided on going to check out a blue hole that I knew of from back when I lived in State College, PA. It turned out to epic as I remembered with a 35’/40′ and 25′ cliff jumps and clear water that has this wild blue/green hue. After wearing ourselves out swimming we heading towards the closest town and walked in the first bar we found. Cheap beers, a jukebox, and some local characters made for a fun time. Finished the day with a ‘family’ dinner at Burger King.

Day 4:
Slept in after staying up late and night swimming when the lake was like glass. That morning we split ways with Devyn, Andrew, and Alex who were heading back to Philly. Ben and I took off for The PA Grand Canyon. Again, tons more miles of great roads all the way there. Made it to Wellsboro, PA where we had a drink at the Penn Wells Hotel which was built in 1869. Charged up our phones and got some recommendations of places to go from some other people at the bar. Checked out the view from the Grand Canyon and setup camp in the State park.

Day 5:

Last day of the trip. Woke up with some coffee and split our last beer and hit the road towards Bloomsburg to check out a cycle museum a guy at the bar recommended yesterday. More fun roads with nobody on them all the way to Bills Bike Barn only to find out they were closed. Fortunately, Bill pulled up in his Willy’s Jeep and Ben talked him into letting us check out a portion of the museum. The guy has some real gems like a Moto Guzzi Lemans 1 in mint condition and a Moto Guzzi dump truck powered by a single cylinder motor.

I like where my license plate sits on my cb650. See if you can find it in the above pic.

Yea… it’s sort of hidden, but it’s also sort of visible from certain angles.

I’ve ridden in front of so many cops through the city for years, and no one has ever given me a problem about the plate placement until yesterday. Some robo-cop dude pulled me over for the license plate not being visible enough. He ended up not giving me a ticket because I played dumb and told him I bought the bike like this and thought it was fine etc…

But, turns out my license expired a week ago. So he was giving me shit about that.

Long story short… I went on PennDOT website this morning to renew my license, and saw this new little button that said “Purchase a record of your driving history”… for $5.

I don’t know about you, but I was a dickhead when I was younger and got a bunch of tickets and suspensions and stuff.

I forget how many times I’ve been pulled over or lost my license, so I got a damn good laugh when I downloaded this. It reads: suspension / suspension / suspension / suspension … ha

It’s funny now because I’ve grown up a bit and have no points on my license and things are all good. But it was a nice reminder of my youth.

No DUI’s. The alcohol related thing was a underage drinking thing at a house party Kevin had when we were 20 and the cops came.

Check out my record

And if you want a copy of your own…
– Log into PennDOT
– click on “renew your driver license”
– then “purchase a copy of your driving history”
– choose “full history”

One thing that is interesting, is that mine seems to start in 2001, and I know for a fact I got at least a dozen speeding tickets before then. Maybe they got wiped away once I turned 18? Do you know Brian? And from what I can remember a few things are missing… like when the lady rear-ended me on my cb650 in 2009 and the cops came.

I was having a real problem finding kits for the cb450 and cb650.

I eventually found kits that drop right in after a little minor boring. No sleeving required. Nice little bumps in compression.

I wanted to share the links to the companies.
Check them out.
They have a bunch of good stuff for the Honda fours and twins.

Dyno Man Pistons

Charlies Place

Note that Charlie Place pistons are made by Weisco to special specs. I think Dyno Man’s are too, but I can’t confirm.
Charlie-Place has electronic ignitions and better regulator rectifiers too.

OEM plus! I love the look of clean clubmans.

Reminds me of the years working on the sidewalk when we lived across the street from the BP where we meet for the Thursday ride.

And I do not miss working on the sidewalk.

Valve adjustment.

Highway cruising back home.

Jesus Fucking Christ. My rotor shit out again yesterday.
Where do I start? This is going to be a long post.

So, the 79-82 Honda cb650 has a shitty charging system.
I realized I’ve never made a post explaining in detail. So, here it goes…

Let me back up a step… In the earlier 70’s, Honda’s had a solid magnetic rotor and the housing was filled with oil. This was good. Honda’s rarely ever had charging problems… and if they did… it was because the regulator rectifier went bad, which was easy and cheap to replace.

In 1979, Honda tried a different type of charging system for 4 years. They went with a rotor which was wound up with wires inside of it, and the housing was not filled with oil. Shit would get hot. Real fuckin hot. Long story short… the rotor would often shit out. My rotor shits out about once a year.

Pic below. Left to right.
new rotor, new regulator rectifier, new stator
These are the 3 components in the charging system.

This is the way the used parts all sit on the bike. (I already took the rotor locknut off)

Where it all plugs in under the seat.

Ok… this is where it gets tricky.

The main thing that will go wrong with the charging system is the rotor.
There are 2 different ways that the rotor will shit out:

1)
The wire on the rotor will physically snap as seen in the pic below. Once the wire snaps, no more charging at all… nothing. It will instantly start draining the battery. You’re not going to make it home. Battery will shit out in about 10-20 mins. Maybe less.

Or…

2)
The wires will visually appear fine, but the reading will be way above the spec 4-6, as seen below. Apparently that means there is an “open” in the circuit. Not sure what that means. Anyway… if this is the case and there’s an “open”, the charging system will still kinda work, but it will be erratic. It won’t directly start draining the battery… at least not right away. It will range from 9 > 12 > 7 > 10…. get what I mean… it will be erratic, rather than holding at the 13.5 – 14 like it should be. So… if this happens, you have a good chance of at least making it home before the cycle shits out completely.

Check out what the Haynes manual has to say about it all.

Getting the rotor off can be a pain in the ass. You need a “gear puller”. Pep boys has them. Make sure you back the lock nut out 1/4″ before trying to use the rotor puller.

Once you replace the rotor, stator and regulator rectifier, shit should be good again. 13.5 at idle and around 14 at 4K rpm.

Ok, so… you know how to replace the 3 items in the charging system.

Let me go into detail about other contributing things about why this charging system sucks balls.

I’ve come to the conclusion that heat is one of the main thing that breaks down the rotor. The stock header sits directly next to the stator cover, so I swapped out to a Mac 4-1. This eliminates extra heat on that side. I also installed an oil cooler to keep the engine a tiny bit cooler.

There are other factors that could make the rotor shit out. Not sure if i’m going to say this right, but if you have something in your wiring which is pulling extra amps, or the circuit isn’t flowing right, this could cause more strain on the charging system. So, basically, just make sure your wiring is the way it should be and your fuses are all good.

So, regarding my situation…
I’ve never had the charging system last longer than a year. I’ve done literally everything I can think of to prevent or offset the rotor shitting out:
– Every piece in charging system is brand new
– Different header/exhaust
– Oil cooler
– Rebuilt my entire wiring harness (check that out here)
– Double checked every connection numerous times

And the rotor still shits out on me. The aftermarket rotors have a thicker gauge wire to prevent it from shitting out, and over time… it still shits out.

I’ve researched this problem for the past 3 years, and there seems to be no real solution other than always keeping a backup aftermarket brand rotor and regulator rectifier on hand, so when your stuff shits out, you have a back-up ready.

One other thing to note is the stator rarely ever goes bad. Every time my rotor shits out,… it takes out the regulator rectifier with it, but the stator remains good. But… if you’re replacing all this stuff for the first time. Def make sure you replace all 3 just for a peace of mind.

Resources to buy the new parts:
– ElectroSport.com
– RegulatorRectifier.com
– ebay
– Dime City Cycles – for lower watt bulb

Good luck. This is the only flaw of this cycle. Unfortunately, it’s a big flaw.

Update – March 2013

I’ve been running all the new charging components as outlined above… with a lower wattage headlight bulb from dime city cycles, and shit has been good for over a year now. No problems. Also… I have a custom switch to keep my headlight off during the day. So… try the lower wattage bulb, but keep it off when you can. It seems to help in conjunction with all the new charging components… and oil cooler, and streamlined wiring.

Made some gusset brackets for the mounting hinges. Good idea adam. They look cool.

License plate… crotch rocket style. Right now it’s zip-tied there (and crooked). I need to make some sort of actual real bracket.

This is what’s left:
– Grind off the excess shit on the seat, and clean it up.
– Paint the underside. Boeshield T9 the top.
– Get my seat pad made by J&J auto upholstery. I think it’ll soften the hard edges of the seat.
– Rig up my tail light. Riding dirty, and sketchy right now w/o one.

Pic below is a mock-up of it on the bike with a seat pad …just so you you can get an idea of what it’ll actually look like on the bike.

I got all the pieces to fit almost perfectly.

Then I spot welded it together…

Then I welded the whole thing together… until I ran out of gas.

Next, I need to finish welding, trim the excess shit off… Grind everything smooth, then make my mount brackets. Then get my seat pad made.

1) Photoshop it out

2) Template it out

3) Plan it out

4) Draw it out

5) Cut it out

6) Check it out

Below is the info you need to get pod filters dialed in on your 79-82 cb650.

79-80 (mechanical piston slide carbs)

• 120 main jet (stock is 92) *** try a 115-117 if you’re at high elevation
• 42 slow jet (stock is 35) *** try a 40 if you’re at high elevation. Drill out the 35 to a 40
• mixture screws set to 1.5 turns out
• float height set to stock measurement
• mac 4-1 header / exhaust (ebay)
• emgo 48mm pod filters (ebay) – (you have to slightly modify the 2 inner pods to clear the choke, i doubled up the rubber sleeve and used rubber epoxy to seal, glue them together)
• Better than pod filters are velocity stacks. Bike runs best with these. They’re a little hard to find though. You want 43-46mm. But… you’ll want to run k&n filter bags. Info HERE.

All jets bought from either:

• http://jetsrus.com/
• http://www.siriusconinc.com/

* Note

If you’re having a hard time finding jets, you can buy a jet reaming kit and drill your stock jets out to the sizes you need.

81-82 (constant velocity slide carbs)

DynoJet makes a kit. All the info you need is on below links (the kit says 80-82, but that is a typo… it will only fit 81 and 82):

• http://www.dynojet.com/pdf/1131.pdf
• http://www.dynojet.com/jetkits/motorcycle/honda.aspx

* Note

All this info for 79-82 is dependent on the fact that you’re living around sea-level, and your carbs are already running good. If you have shitty carbs, you might wanna rebuild them and get them clean as fuck before you attempt putting pods on. If you’re high up in the mountains, you want slightly smaller jet sizes than what I spec’d out.

* Note

The cycle will run a little hotter, simply because you’re going to be making a significant amount more power than stock. Makes sense that more power (more of an explosion in the combustion chamber) is going to create more heat. To offset this extra heat, I recommend adding an oil cooler. INFO FOR THAT HERE. Also, for 79-80 carbs, my set up is the tiniest bit rich, so it’s absolutely not running lean. Lean would add extra heat. My spark plugs have been a perfect light-golden brown for years now. No problems at all.

Here’s what I did in the last step:
– Re-did my wiring, I cut out about half my wires. Props to Adam!
– Installed oil cooler
– Spot-painted frame
– Re-mounted gauges lower and tighter
– Installed new rings, assembled engine. Props to Nick!

– Original wiring

– Shit we cut out

– New wiring… streamlined!

– Ready for the engine to go back in

– All back together

– Gauges mounted lower and tighter

– Custom headlight switch, mounted in fork ear
– Oil cooler adapter plate which makes the entire cooler set-up work, purchased from:

www.randakks.com

Thanks to everyone who helped. Couldn’t have done it without you guys. Extra special thanks to Adam, for his intricate wiring knowledge, and Nick for his master engine expertise.

Side note:

To make the oil cooler set-up work on most old 70’s 4cyl hondas, you need a special adapter plate which sits between the engine and the filter. It’s almost impossible to find the right adapter plate with bolt on ebay. Finding the Lockhart cooler was easy. Finding the adapter plate which makes the whole thing work is the hard part.

I couldn’t find it anywhere except this dude:
www.randakks.com/Engine%20Parts.htm#2

So, I paid the $150, and it works perfect. Everywhere else that was mentioned in other blog posts that sells them, does not sell them anymore, except this place.

They cleaned and checked everything, installed my new valve seals, cleaned up the combustion chamber, intake and exhaust ports. They also said I had 1 leaky valve, so they fixed that too. Turned out great, quick turnaround, friendly guys, $110 charge for everything. A while ago they also did the cylinder head on my S2000, and checked out the cb450 head for me, so I can recommend going to them if you have engine work that you want done.

Next, and last step, is re-assembly of the engine with new rings, installation of a Lockhart vintage oil cooler, go through my wiring harness to check everything, and then fire it up.

The engine leaked a shit ton of oil from the rubber o-rings around the head gasket. (Common 4cyl problem on old Hondas.)

My engine fins have always been completely covered with caked on oil, grease and dirt. If you didn’t already know, the engine fins are what cool your engine. So to say the least, my engine prolly wasn’t properly cooling itself as much as it should have been. No matter how much I cleaned it, 2 weeks later it was gross again.

In my plan to reduce overall engine temperatures, and efficiency, I’m doing a new gasket kit, having the cylinder jugs measured, and having the cylinder head pressure tested to see if everything is still within spec. Possibly installing a cb750 oil cooler.

Step 1 – Get the engine apart
Step 2 – Clean everything
Step 3 – Have cylinder jugs and cylinder head tested
Step 4 – Reassembly with new gaskets, new piston rings, possibly oil cooler

* For a complete, exact step-by-step tutorial, consult a real manual. I’m just gonna give the basic steps.

Step 1 – Find a 17mm bolt.
You have to loose the bolt on the top of the fork. It’s a 17mm allen key. Of course no one has 17mm allen keys, so if you can find any 17mm bolt (like the oil drain bolt). You dont wanna use the oil drain bolt because you dont wanna strip it out, so find any other 17mm bolt and grip it up with vice grips as a “make-shift” wrench. Loosen the top two bolts.

Step 2 – Take front wheel off / Loosen the triple tree
This is pretty easy. Take wheel off… Support cycle on milk crate. Once the triple tree bolts are loosened, slide the forks down and off the cycle. You’ll need 2 people for this shit. One person holds the cycle up, while the other person slides 2 milk crates under the head tube. So the cycle is now supported on the center stand, and milk crates.

Step 3 – Forks are off… Now take them apart
This is super easy, just label everything and stay organized as to how the parts come off in sequence. Top comes apart first, then bottom.

Step 4 – Get the fuckin old seals out
This part sucks really bad. The only way Adam and I were able to get the seals out was to grab his torch, and heat up the fork tubes in the spots where the seals sit. Don’t over heat it… Just get it pretty fuckin warm, so the aluminum will expand and you can “pop” the seals out. I used a box wrench wedged under it, and hit it with a hammer until they popped out. Like I said. This part sucked really bad but we eventually got it.

Step 5 – Clean every part of the fork with brake cleaner
Again, this is super easy, just make sure to get all the old oil and gunk off everything. Once every part is clean, lay the parts out on a clean sheet.

Step 6 – Oil everything
I went to the Triumph dealer in manayunk and bought 15W fork oil. The manual called for 10W, but I read online that thicker oil is better for older cycles to help stiffen it up. Anyway, as all the parts are laid out on the clean sheet, with your finger, dip it into the quart of oil and oil every piece.

Step 7 – Reassemble
This is exactly the same as disassembly, but reverse.

Step 8 – Put new seals in
Once the forks are mostly together, slide the new seal over the top tube and down to where they sit in. I used an allen key to gradually push the seal into the area until it finally popped in.

Step 9 – Fill forks with new oil from the top bolt
On my cycle, according to the manual, each fork leg took 5.7oz of new oil. Once each is full, tighten the top bolt up.

Step 10 – Put forks back on the cycle and tighten everything up to spec
This is exactly the same as disassembly, but reverse.

After it’s all said and done my forks feel a little stiffer, plus no more oil leaks out. Pretty cool. Oh, and it took us roughly 5 hours. Not too bad for first time doing it for both of us.

I guess I didn’t read the fine print in the eBay post because when I got the package in the mail, there were 3 cables, bolts etc… in there.

So, I have 2 extra cables, bolts and washers. The cable is 30″ long, so it fits the 650 perfect with basically no slack.

If anybody wants to replace their shitty cable with a legit one, hit me up. You’ll def notice a huge increase in braking power.

Either flow me $20 bones, or get me drunk at N star, and it’s yours. Let me know…

I found a used set on eBay for $27. Got them in the mail in a few days.

• lubed them with various cleaning / greasing shit
• cleaned the throttle sleeve and put a thin layer of grease between the sleeve and the handlebar to keep it smooth
• made sure the mushrooms were feelin fresh
• since I had all the tools out, I took the 450 throttle cable apart too and lubed it up, to make sure both bikes cables were feelin smooth as shit