GSR please save my bike! major oil leak on startup after rebuild

[Guest]

OK, long story short, i have a 1979 gs550, at the end of last year i developed a minor oil seepage from my base gasket. So over the course of the winter i have disassembled my motor, cleaned, painted, and purchases new suzuki OEM gaskets to rebuild with.

Step one, tore down the head, ran in acid bath/hot tank for a day, cleaned valves, lapped valves, installed new valve seals, measured valve clearance. That all checked out ok.

upon assembly of the motor i followed my haynes manual to the T. cleaned all the mating surfaces of engine parts with brake cleaner and a razor blade, and a 600 grit sandpaper. I cleaned the cylinder bores with a air grinder and 3M roloc aluminum sander "finger style" i guess you call them, discs. They remove the gasket but not the material.

NOW, the fun part. Last night i assembled the motor, put everything together, and BOOM fired it up on the 3rd kick like normal. And then all hell breaks loose.

Right around the #1 cylinder, bottom of the cylinder bores where the bores meet the crankcase its POURING oil, like i mean its just draining the thing. I used SUZUKI OEM gaskets, o rings, everything!

So tonight i pull EVERYTHING apart again, bring out the spare set i ordered for that "just in case" situation(here it is...) Double check my surfaces, yup, clean. this time i used some black RTV around the O rings and that particular area where the leak is, and well you can guess what happens next...

still leaks...

im dumbfounded. Im a 4th year apprentice toyota mechanic and consider myself extremely mechanically inclined. This has me stumped! The only idea i can fathom is that my mating surfaces are not flat. ill rip it apart and bring a straightedge home to "square" things away. yukyuk


I really could use the help, this has me scratching my head.

[7981GS]

Did you remember those egg-shaped O-rings that go in the base gasket in those corners?

Daniel

[SqDancerLynn1]

Parts fish calls for an O ring at that corner. ????

[rangerdanger]

Brand new. both sides. is there supposed to be an alignment pin like in the front there as well?

[mlinder]

Back of the jugs. Weird oblong egg shaped indentations on case, oil galleys. Orings go there.
You took 600 grit sandpaper to the mating surfaces?

[chef1366]

If it's pouring out like you say than that breaks it down to where the oil is pumped up through the cylinder into the head.
Since you are a mechanic I won't insult your intelligence and ask if you followed the proper tourque sequence and tourque pounds.
If you did it twice I'd say you have a problem with the mating surfaces and it may behoove you to get the surfaces checked and machined.
I'd also check and make sure the dowels are lined up and mating properly. (first) If they are anything like mine there are two in the rear.

[mlinder]

Chef, dowels are in the front on the 550, but good points regardless.

[mlinder]

#6 here: http://www.bikebandit.com/1979-suzuk...6071#sch284030

[7981GS]

Have you tried a small circle of Ultra Blue or Black around the dowels?
(Both sides of the gasket)
Just like on a water passage on a V-8.

Daniel

[mlinder]

Brand new. both sides. is there supposed to be an alignment pin like in the front there as well?

No. There isn't.

[Suzuki_Don]

cleaned all the mating surfaces of engine parts with brake cleaner and a razor blade, and a 600 grit sandpaper. I cleaned the cylinder bores with a air grinder and 3M roloc aluminum sander "finger style" i guess you call them, discs. They remove the gasket but not the material.

Not sure what you mean by this. But if you cleaned the lower surface of the cylinder face or the upper surface of the crankcase with these 3M products I would say that is your trouble. Maybe you use these techniques at your workplace but not on a 30 year old motorcycle. Car motors are either metal or harder alloy than is used on our motors.

By all means bring home a straight edge and run it over your motor (good luck getting the studs out of the crankcase). I can tell you now it will not be the egg shaped "O" rings that are leaking, it is something else. And keep that silicon away from these motors. A bit of grease on each side of the base gasket and on the valve cover gasket is all that is required.

The fact of the matter is that there was only oil seepage originally and now it is pouring out. So something has happened between pulling the motor down and putting it back together again. Examine your work practises. Look for something you might have done that could cause a mismatch of those surfaces (you did put a base gasket back in place with the two egg shaped "O" rings didn't you.

If all else fails take the various parts to your workplace and get other opinions from work mates.

How about some pics of engine assemby.

[Nessism]

Silicone sealer goop should NOT be used on the O-rings or base gasket. And I agree with Don, those roloc things are dangerous. A machinist recently told me he's seen a LOT of damaged parts due to those stupid things.

[mlinder]

I still can't get past the 600 grit sandpaper used on mating surfaces...

[UncleMike]

I still can't get past the 600 grit sandpaper used on mating surfaces...

Seems like that alone would be enough to augment the mating surfaces and cause a leak.

[TheCafeKid]

I still can't get past the 600 grit sandpaper used on mating surfaces...

Yeah that's a little stout. I used 1500-2000 grit to clean and prep valve covers for a new gasket and maybe non pressurized gaskets like clutch cover stator etc. But 600 would leave a good deal of little gouges in that surface. Anyplace that isn't flush plumb or flat is gonna let oil seep past.
Perhaps with a car engine, the higher torque down numbers allow for this, but these are a little less tollerant.

Say Mike, totally off subject, what tire size did you end up goin with?