Topic: getting ready to change my crank seals

[purf_man]

alright as some might remember (I doubt it) I have a 1975 cb550k with a leaky crank seal (may have been damaged in a wreck from debris....who knows)  I ordered up a gasket set AND the seals (why can't they sell them together?)  I am picking up an under frame lift/jack to use whlie doing all this and have a buddy lined up to help heave the motor around.  now the important questions...

I am told you can just split the cases (leaving chains intact) and gain enough room to slide the selas out.  I am planning on this route but might go a step farther and pop the cam out (wire the chains to pull it back up) so I can slide the top of the motor (topend and all) up until all the pistons bottom out in the bores which should give me plenty of room to shimmy in there.  after this you just seal up the cases and button it up right?

as mentioned I bought the full gaskets to be perpared just in case I have to pull the topend off the cases.

the mystery question...

are there any oil passages I need to seal or get orings in between the cases that would require full access to them?

how tough is it to wiggle the carbs off the motor/bike?

well if I am successful I have a full set of covers polished ready to go on the bike and am leaning towards tossing a cam in it if she is leak free and porting out my spare intakes and a worked over head (I have a spare)  but that is all down the road a ways...

so will this work plan work for me?  or do you HAVE to do a full teardown?

[bryanj]

No "O" rings (except in head and base gaskets

Carbs are a #$%*

DO NOT loosen the head/barrells  UNLESS you are going to take them ALL the way off and replace gaskets.

BE advised that primary chains wear a lot and need the crank out to change

[purf_man]

so popping out the cam and backing off the adjuster should giv eme enough room to work between the cases?  I figure this should give enough room to get a look at the main journals to see if they are toasted looking.  if I can slap it together for the cost of the seals and a little sealer then I will be happy.  if it needs torn down then I might be looking at a head porting job (have a spare) and putting in a cam I think.

going to start pulling things this week and maybe get it out and split this weekend depending on how things go.  I figured a little each night doing things like pulling the header, covers, drive chain carbs will pay off giving me plenty of time once th eweekend gets here to pull the lump and go into it.

[rhinoracer]

If you're not planning on pulling the motor off the frame I would try and take the seal off without cracking the cases open (Don't know if possible on a 550, my 750 seal has a smooth outer diameter) and just loosening the main cap for the seal end.

Otherwise you might end up with more leaks than you started with.

[purf_man]

550 cases are the main caps.  planning on pulling the motor out just not taking the whole motor apart (leaving top end in place)  I think I am going ot go pull off some small parts tonight (header, chain, stator) and drain the oil.figured I would do alittle each night this week and hopefully have it all lined out for this weekend.  this is the first 4 stroke multi clyinder bike motor I have messed with (built a few automotive motors though and a couple 2stroke dirt bike motors)

[Bodi]

Remove the cam and tie a string around the chain. Set all 4 cylinders to 1/2 way between TDC and BDC. Undo all the case bolts on top first, then flip it over and undo the reast. Lift the bottom case off, you will be able to lift the crank plenty enough to see the top journals, at least an inch (the stroke is about 60mm right? half the stroke, anyway.)
If you just want to do the seals you don't have to lift the crank more than a few mm, loosening the adjuster might be enough but slipping the chain off the sprocket will be plenty.

[purf_man]

well I put the bike up on a lift tonight.  pulled off the stator and countershaft covers.  popped the oil pump off so I can get in there and clean real good (rubber stoppers in the holes)  and pulled the 4-1 header/muffler off the bike.

is there any good solution to crudy looking exhaust clamps?  I still have the factory ones holding the head pipes to the head but they are kinda sorry looking.  I was thinking maybe just see if I can get them blasted somewhere cheap and soe BBQ black on them?

[purf_man]

well stripped just about everything but the motor mount bolts off tonight.  carbs and all.another hour to pop off some mounts and out it comes (need to find a helper first)  so it is coming along.  need to order up some yamabond and a flywheel puller and then I will be set to really take off on it.

[purf_man]

well breaking wn bits I was looking at the head and forgot it was weeping a little bit....I do have gaskets on hand...

or should I leave it alone for now and if the fix takes R&R the top end later on?