• Enter the March CB750 Supply gift certificate giveaway! It's easy... Click here, post something, and you're entered into the drawing!

How to install new cylinder head cover bolts?

The Jimbonaut

The Jimbonaut
Messages
67
Reaction score
0
Points
6
Location
Montreal
Hi guys,

The rubber grommets on my cylinder head cover bolts are shot (crumbling big time) so I bought some NOS replacements yesterday. I've removed the 4 outside bolts from the cover (not the 4 inside ones yet), but I don't know how to a) remove the 4 inside bolts and b) install all 8 of the the new bolts. The grommets will have to come off first I'm guessing, but how? And how to get them back on without damaging the rubber?

Thanks as always,

- J
 
You can oil the rubber lightly or throw grommet in very hot water to make it more pliable for a minute.

Whatever you do, when installing cover simply run all down at the same amount in an attempt to hit all at close to same time and then hit all down to the solid hit and just enough more to not be loose. Torquing them is what strips the holes in cam cap out, people do it so much it's beyond belief.

Many cars (like my two Focus) are like that too, the bolts have a positive stop shoulder and if you insist on 'torquing' them you can plan on lots of stripped out holes.

A tip.............the 6 mm. shank used on bolts on these bikes like valve cover, cam caps, and front cam chain tensioner are often mentioned in service manual as torquing to 10 ft.lbs. or so, they STRIP at below that and common.................use 6 to 8 MAX and don't get carried away with it. The valve cover bolts all interfere with each other and why they will NOT back out, the grommet stops that too. The bolts as well are super soft and break at even so much as a hint of 'torquing' them, why so many of the cam cap holding bolts break on these too, same thing 6-8 MAX!
 
Thanks again amc - sadly looks the damage has already been done by a precious owner on several of the threads. Can chain tensioner bolt thread? Stripped. Bolt securing the tach to the cylinder cover? Stripped. Wonder what else I'll find the deeper I go...

Incidentally, replaced the necessary shims yesterday and now have clearances of 0.005 (+/- 0.001) across the board. Thing is, when I ran a compression test, the psi on cylinder 2, which was 150, has now dropped to 130. Puzzled. The exhaust valve clearances are now better (before they were 0.003) - lower compression was not what I was expecting.
 
You gotta get it up and running and frag it for a bit. The valve seats when allowed to close up clearance build up carbon on them and the valve then reseats a bit different every time. The fragout hopefully beats some of the carbon off, it's worked for many before. Recheck the clearances after, if real bad you often find the beating off carbon has closed a few of them again but you are getting down to true valveseat material and eventually it steadies up. Or shows true damage done by running them too close to burn.
 
Back
Top