Comments on: cb650 engine rebuild Step 1 of 4

By: David

David — Wed, 11 Apr 2018 16:57:35 +0000

I have an 82′ cb650sc and is only firing on cilynder 3. any ideas?

By: mike morris

mike morris — Thu, 20 Jul 2017 01:19:40 +0000

where does it tell me / show me how to get the engine apart?

By: Terry

Terry — Thu, 21 Apr 2016 22:20:13 +0000

I have a 1980 CB650C also. I have a couple of small very minor problems with the engine until now. I sheared one of the valve steam adjuster screws and need to replace it, probably need to take the engine out to fix this. Do you think it would be worth it for me to do a total engine rebuild while I have it out? I don’t have any leaks or issues, so maybe this is entirely unnecessary.

By: Joe

Joe — Wed, 11 Nov 2015 01:52:45 +0000

I have just started a tear down of my 82 CB650SC. I have owned it from 1984 and the last time it was on the road was 93. I have taken it down to exposing the pistons above the crank and everything looks good. Very little scoring in the piston sleeves and the valves look extremely clean. Will flip over tomorrow and expose the crank shaft to see how much rust dust it has collected. I have only found very light rusting inside and it was easy to take apart.

By: Neal

Neal — Thu, 19 Mar 2015 17:57:09 +0000

I was wondering…on this rebuild, did you address main and con rod bearings?

By: jeff

jeff — Thu, 05 Mar 2015 05:26:12 +0000

hey gasket kit did you use? and feedback on quality/fitment? thanks!

By: ed

ed — Mon, 23 Jun 2014 14:58:55 +0000

@Rick
It depends. Below are super generalized estimates.

If you’re just doing gaskets and cleaning. $100-200

If you’re doing pistons / head work / machine shop work. $500-800

By: Rick

Rick — Sat, 21 Jun 2014 19:01:36 +0000

How much does it cost to rebuild a cb650 engine

By: Salzig Hund

Salzig Hund — Wed, 26 Mar 2014 18:40:26 +0000

Thanks a bunch for the insight and photos. I’ve had my engine (650) on the stand for months because I wasn’t sure what to do. Your photos and quick run though of what you did was helpful. Going down stairs to deal w/ it now. Please tell me did you:

1. Hone the jugs/ cylinders
2. replace crank case gaskets? its sat for 21 years

By: admin

admin — Wed, 22 Sep 2010 18:35:24 +0000

Just to clarify, I never split the crankcase. We only took the head and cylinders off, which was super easy. Once you get all the bolts out, just use a rubber mallet to tap the cylinders and head loose.

-Ed

By: Kyle

Kyle — Fri, 27 Aug 2010 00:44:40 +0000

Great Site! Very excited to see that there are other vintage bike enthusiast out there.

What is required to separate the two halves of the engine? I got to replace a gasket to stop an oil leak. Thanks!

By: admin

admin — Mon, 23 Aug 2010 22:00:53 +0000

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By: admin

admin — Mon, 23 Aug 2010 21:52:20 +0000

yea