Topic: cb550 headgasket

[pinnacle]

i got my gasket kit from partsnmore and am ready to tackle the leaking headgasket now before i do is it a fairly easy job to do with motor still on the bike? will i have to remove the cam and chain and then have to set the timing again and what precautions do i take so not to screw anything up? is there any point in lapping the valves if they are not new should i do it also? anything else i should do to the head while it is off that will imrpove the 550 without getting into expensive head work? some advice please. the bike is a 1978 cb550 k with 43000 km and blowing smoke from tail pipe.

[OldSchool_IsCool]

Do a compression test before you pull 'er apart.  Run a "dry" test and a "wet" test with a teaspoon of fresh oil in the spark plug hole first.  You want consistant pressures accross all 4 cylinders in both tests.  If the wet pressure is say 10% higher then the dry test, then your rings may need replaced.  Good to know that before you crack her open.

Also, by taking the head off, you will likely disturb the base gasket (case to cylinder block interface).  May want to replace that gasket too.  that means pulling the cylinder block off the pistons. 

I use brake parts cleaner to clean up the carbon. 

Yes, the cam shaft is guna need to come out.  Be sure to back off all 8 tappet adjusters before pulling the head.  Also wire up the cam chain so it doesn't fall to the bottom of ur engine.

Inspect your cam chain tensioner too.  If it has deep groves warn into it or the rubber is deteriorating, you may want to replace the tensioner blade and cam chain too.

Take care not to plug the holes at the far ends og the head and cylinder blocks.  These carry oil to the cam bearings.  Plugged oil gallery will KILL your cam pretty quick!  Keep the holes in the bottoms of the cam bearings clear too.

When you put it back together, the base and head gaskets go on dry.  The "pucks" (aka sealing rubbers) should have a thin couat of aviation sealer or 1104 or hondabond.

OK, I know that was a lot of info, and there is a lot more too.  May need to work through this a step at a time.

[bryanj]

Dont forget all the "O" rings in the gaskets and the pucks between cam cover and head also read manual CAREFULLY about re-fitting cam cover unless you want bent valves

[pinnacle]

will i be disturbing the timing and if so is there any precautions i can take so as not to?

[Gordon]

will i be disturbing the timing and if so is there any precautions i can take so as not to?

You can't remove the head without also removing the cam shaft and sprocket.  Just follow the procedure in your manual when putting everything back together and it will be set properly. 

[OldSchool_IsCool]

On a scale of 1 to 10 with 10 being the hardest fixes, this is a 6.

[Gordon]

On a scale of 1 to 10 with 10 being the hardest fixes, this is a 6.

I prefer to think of any project as a certain amount of #1 level tasks.  The more difficult the project is supposed to be, the more #1 level tasks it contains.  So on my scale, this would be six #1 level tasks in a row.