1981 CB750 Cam cap question

lostinmiself

lostinmiself

Active Member
Doing some general maintenance on a bike i purchased not to long ago, noticed the valve cover gasket had a leak at the cam end plug seal, so i am replacing the gasket. Upon re-tightening the valve cover bolts i noticed the front center two bolt holes were stripped. Can i replace just the two cam cover caps without removing them all and torquing them down or am i going to have to remove all the caps and torque them all down at the same time?
 
I take the bolts that hold the cam cover on screw into the tops of the cam caps like a GSXR engine.
If so you may be able to get the threads repaired.
Can you remove just two of the caps and leave the others in place, yes, so long as you don't run the engine, you aren't going to bend the cam.
Can you replace those cam caps with second hand ones from another engine, engineers will tell you no, because they are line bored, but practically you can do it - I did this on a GSXR750 and never had any problems.
 
http://lh4.ggpht.com/_awDuVaHRyjA/THNdiIYcVZI/AAAAAAAAAV8/svpZMfH8G20/s640/CB%20750%20Custom%20079.jpg

See how the cap under the frame has the valve cover bolt that screws in to it, that is stripped. Not sure how the PO had it rigged but i intend to fix it the correct way. I am new to dohc cb750s so i wasnt sure if i could remove the damaged caps and retap them without causing issues. From your reply i should be good to go then. no reason i couldn't retap it rather than trying to source another cap
 
You want to take it off and helicoil it rather than get another one - they are numbered and line bored with the head so you aren't supposed to swap them around or mix them up.


You will want new rubbers under the bolt caps - they compress over time and people will try and tighten them too much which causes the threads to strip. And best to get a new gasket as well.
 
Do yourself a favour - get a drift that fits inside the head of the cam cap bolts and give them a good whack with a hammer before you try and loosen them. Otherwise you risk snapping the bolts (its surprisingly easy to do) and you'll end up with bigger problems.


Make sure the cam is positioned so the valves are closed on that side and you can remove the cap with no damage to the cam.
 
Well i removed them before turning the engine, not much i can do now. I will get them helicoiled, i was thinking that as well but was unsure weather that was the best route. I am ordering valve cover grommet gaskets as well as the speed-o gasket, already have a new valve cover gasket. thanks yall
 
When you get the new bolt grommets compare them to the old ones and you'll see why people tighten the bolts until they strip.
 
I doubt its any different than when people do the same to valve covers on honda car engines. Although they are a little more forgiving, i assume the rubber is suposed to be all the way down the shank of the bolt not half way and sloppy
 
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