Topic: CB550 head cover crack

[Retroben]

I posted this over on my projects thread, but I'd like some more opinions:

Noticed this while adjusting the valves:
http://i1093.photobucket.com/albums/i422/bfranchi/1978%20CB550K/2012-09-07_12-53-59_827.jpg
http://i1093.photobucket.com/albums/i422/bfranchi/1978%20CB550K/2012-09-07_12-54-53_835.jpg


Does this warrant replacing the head cover?
I also saw silicone goop inside the exhaust chamber tappet area. There is also silicone goop seeping out all the way around the head cover-head mating surface. Now I know for sure someone has had the head cover off. Hope they didn't wreck things too bad in there, and wonder what they were doing in there anyway on a bike with 11k miles.

Some of the tappet adjuster locknuts showed signs of mistreatment. No wonder the gaps were all over the place.

Well, this is looking less and less like the first resto job I actually can make any money on. Glad it's so much fun...most days...

[Stev-o]

I would change it.  On the 550, you should be able o do it without pulling the motor.
And get all silicone out, if it clogs oil passages, you are going to have acbigger problem.

[dave500]

yeah find a new one,,thats caused by leaning on those screws first,,do those inside four first working the rear ones then those front ones last,they only need a nip down,,they aint wheel nuts!be sure to have all the tappet adjusters backed well off aswell,itll put less pressure on them all.

[Retroben]

What would be the consequences of not replacing it right away (with relatively easy riding)? Can I get this bike running in the meantime without damage?

I think I got all the excess silicone off the inside, at least where I could see. There wasn't much, actually more on the outside of the engine. When I removed and cleaned the oil pan there didn't seem to be any silicone bits in the sludge at the bottom of the pan, and no foreign matter in the oil sump screen. Of course, if I have a totally blocked oil passage somewhere, I'm not going to know that until it's too late, right?

[dave500]

itll leak probably,remove an outer tappet cover on each side and start the engine,youll see if you have no oil flow quickly.

[lone*X]

When you replace the rocker cover, be sure to get one with the rocker shaft locking pins.  The 74, 75, and some 76's didn't have the locking pins and the shafts rotate in the bores and wear them oval which caused a misalignment between the rockers and valve stems, accelerating wear.  I believe late 76 thru the end of production had the locking pins.