Topic: 77 CB550 Top end leaking oil??

[sniper1]

I noticed that the head is leaking oil, not at an alarming rate but enough to make me worry. What am I in for and what should I be looking for? I'm thinking a new head gasket for sure, but what else? How much work is it? Any assistance would be appreciated.

Thanks,

[shizzomynizzo]

If it's leaking so little that you do not have to add oil in between normal changes, don't worry about it.

[steam-powered man]

there's a few places that may leak on these bikes, with varying degrees of difficulty in making the repair.  

a leaking valve cover gasket can be replaced wtih the engine in the bike, but care needs to be taken when removing and replacing the valve cover (the cover is also the cam holder).  

the valve adjuster caps can leak (my "o"-rings were rectangles). the end caps can leak (sealed with 2 "o"-rings).  the aluminum washer under the end cap bolts can get mushed (like mine were)and leak.            

[gregimotis]

there's a few places that may leak on these bikes, with varying degrees of difficulty in making the repair.  

a leaking valve cover gasket can be replaced wtih the engine in the bike, but care needs to be taken when removing and replacing the valve cover (the cover is also the cam holder).  

the valve adjuster caps can leak (my "o"-rings were rectangles). the end caps can leak (sealed with 2 "o"-rings).  the aluminum washer under the end cap bolts can get mushed (like mine were)and leak.            

Does the 550 have the same habitually leaking head gasket / rubber pucks as the 750?  That repair certainly requires an engine pull and considerable teardown.


I used a trick posted on the forum a while ago to locate the source of my head leak and it worked beautifully:
Clean all the fresh oil off the engine and then spray a can or two of athletes foot powder all over everything.  Run the engine and the bright white powder will turn jet black at the source of the leak - it'll be clear as day.
After the powder rinses right off.

[OldSchool_IsCool]

+1 on the foot powder trick.

If the leak is small, you can cram a rolled up paper towel or chunk of cotton rope in between the fins to keep your pant leg clean.  Change the packing when saturated.  If your paper towel expenses exceed your dry cleaning bill, then it's time for a tear down.

[steam-powered man]

valve cover is easily removed with the engine in place on my 77cb550, i've done it.  replaced valve cover gasket, pucks, etc.

[lefty2023]

so you dont have to remove the engine from the frame right? all the manuals i have say you dont have to but i just want to make sure. mine is leaking oil on the left side between the head and the block

[TwoTired]

How bad is the leak?
At each end of the block is an oil passage going to the cam, etc.  They have o rings for a seal that harden with heat/time. They seldom do more than weep annoyingly, requiring a wipe off once a week or so.

I just ignore mine until it starts dripping on me.  Then you must remove the head to access the o rings.  If the cylinder base gasket gets disturbed (likely) then you have to take the cylinder block off too, to replace it, along with all the gaskets/seals from there up.

If you break a ring you have a ring job and boring/hone to do.  If you install the cam cover(cylinder cover) improperly, you'll have bent valves to replace.

Yes, all the work can be performed with the engine in the frame.

Cheers,

[Gordon]

so you dont have to remove the engine from the frame right? all the manuals i have say you dont have to but i just want to make sure. mine is leaking oil on the left side between the head and the block

You can do all of the top end work with the engine in the frame on all sohc4 models, without frame modifications, except for the 750K and 750F.