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)
- 42 slow jet (stock is 35)
- mixture screws set to 1.75 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)

*** all jets bought from either:
- http://jetsrus.com/
- http://www.siriusconinc.com/

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 over a year now.

-Ed

The 650 rebuild is finished. It’s running pretty damn good. Going easy on it for the first few hundred miles.

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.

-Ed

I’m adding a vintage Lockhart oil cooler to my 79 cb650 for several different reasons. Read the below article. It def outlines a couple of my reasons.

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.

-ed

Cleaned everything as best I could, then I took the head and cylinder jugs to Mar automotive in the near northeast.

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.

I’m rebuilding my 79 cb650 engine.

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