Topic: early 550K cam cover wear O-ring fix- in practice

[Klark Kent]

so i finally started seeing a weep from my throttle side cam cover.  with a K1 550 approaching 30K i had been advised to expect/prepare for/pray about it.  Upon inspection i found the intake side cam cover plug to be slightly shorter than the exhaust plug.  I put an o ring with an outer diameter of 12mm in both holes thinking that this is both a cure for the effected rocker shaft cap and a preventative measure for the one that apears in tact and i planned on putting o rings in all the holes, but the wear was significant enough that this seats the cam cover ever so slightly off flush with the engine.  not by a hell of a lot, maybe half a mm 

Pics will follow when i can get to a digital camera and the bike, but if anyone (TT) can tell from my butchering of the terminology, and haphazard guessing about the half mm gap whether i should be putting O rings all around and maybe an extra in the spot with the wear to obtain a flush mount, or if a single o ring to stop the wear and an eye on the others is the way to go, that would be cool too.

thanks
-KK

[bryanj]

There are two possible leaks
(1) the "O" rings on the pegs in the cover that seal the rocker shaft bores
(2) The soft washer under the fixing bracket.

If the shafts have worn the cover holes oval no amount of tinkering with "O" rings will cure it

[clarkjh]

I just replace all four O-rings, $6.79 Cnd from Honda.  My leaks gone.

James

[Klark Kent]

one of my rocker shaft holes is oblong.  at this point i need to replace the cylinder head cover and the two side covers, which show wear, right?  how long (far) can i ride it until then?  would 300 miles of 7krpm r less be within the realm of making it without screwing my cam shaft?  i can order the end covers from honda still, and i have a cylinder head cover in NY (300 miles away right now  ) so, i would be interested in anyone with the parts in good shape close to baltimore.

[TwoTired]

If you just want to stop it from leaking, new orings should stop the leak.  The rocker wear is in a different place than where the orings seal.

Oblong wear in the cam cover usually kants the rocker and causes the cam follower and the cam to wear toward one side of the lobe.
When the cam follower load is no longer spread across the entire lobe face, the resultant uneven wear is not recoverable without a regrind of the cam.  The rocker follower faces also gall from the ordeal and either need to be refaced and surface hardended or replaced.  Of course, the cam cover must be renewed also.  The extent of the damage must be assessed on disassembly.

I've not seen it, but it is possible the cam cover can wear so that valve movement telegraphs through the rocker shaft, which frets against the cam cover end plugs.  The movement would break the oring seal as it oscillates.  A possible stop gap fix would be to replace the orings in the end plugs and put an extra oring between the end plug and the rocker shaft.  If the cam cover wear is not too severe, this extra friction of the oring, stops or retards the rocker shaft rotation and further wear on the cam cover.

These run a long time in the worn condition and 300 miles is not significant.   If I had to guess from your description, it seems likely your cam is already worn unevenly.   Shop for a cam and cam cover from a 77-78 CB550.  A matched set would be ideal.

Cheers,