Ring and Gasket Sealing Questions

[Guest]

I finally finished my rebuild of the 79 GS 550 and it runs like a champ! But the problem comes with an oil leak. I rebuilt the engine, replacing the rings, wrist pin snaps, honing the barrels, lapping the valves, new stem seals, valve adjustment, etc. When I finally finished it, however, I found that it leaks oil at an unbelievable rate - obviously a problem with the rebuild.

It appears as though the base gasket is the culprit, (not the mystery hole, lol) and I am preparing to rebuild the engine again with new gaskets hoping to finally seal it. Thus I'm wondering, since gaskets compress once torqued, could a gasket torqued down twice not seal? (I would replace all the gaskets anyway). As well, what gaskets would experienced GS rebuilders recommend to encourage a solid seal?

As well, the rings I used in the previous rebuild have less than 2500 miles on them, but I'm concerned about reusing them. Question: Do rings ever fully set a second time? Or must they be replaced once pulled out of the barrels regardless of wear or condition?

I would appreciate any light this grand community could shed on this, let's get these beauties on the road where they belong!

[gearhead13]

Stock Suzuki gaskets are best. Have you done compression tests to check the condition of the rings/bore? THAT will be a big factor in whether to use the same rings again. Definatly a new hone job whether new rings or not. Many here say that even pulling the head requires a new base gasket, it disturbs the seal. I always use a sealer on my base gaskets, just around the oil passages, as well as on the oil passages around the head gasket

[Suzuki_Don]

I would say most likely the oil leak is around the egg shaped oil seals at the rear of the cylinders. Did you replace these "O" rings.

I make my own base gaskets, but failing that use ONLY Suzuki OEM base and head gaskets.

In my opinion, replace base gasket, egg shaped "O" rings, head gasket and rings, plus a hone and everything should turn out OK for you.

Cleanliness is the key, remove every trace of gasket material or a leak is most likely.

I NEVER use sealer on any of my gaskets or mating surfaces, a little grease sometimes to hold things together and help in sealing initially, but that's all.

[derickson104]

All right, that's all excellent information. As a matter of fact, I did replace all the o-rings, even the egg-shaped ones near the corner of the cylinder base - the leaks surprised me, to say the least. As did the information about aftermarket gasket kits. I assumed they met the same specs as the OEM and would seal, as one would expect from a gasket.

The compression test and a new hone are no problem, though I am curious if anyone knows if Suzuki sells OEM gasket kits? As well, I've heard that using a sealer, like a permetex RTV on lower gaskets (head and base) can cause the sealer to mix with the oil and, well, 'slow down' oil flow throughout the engine, has anyone experienced anything like this?

Once again, thanks to the great GS forum front, you all are invaluable!

[Suzuki_Don]

Just buy the Suzuki factory gaskets and "O" rings from your local dealer on a "needs" basis, don't worry about trying to buy a kit - you wouldn't use half of the gaskets anyway. You only need a cylinder base gasket, egg shaped "O" rings, rectangle "O" ring between cylinders and head for cam tunnel, cylinder head gasket and maybe a valve cover gasket depending on the condition of the one you already have.

BTW there are seals on the head gasket holes where the studs pass through and enable oil to pass up to the cylinder head and cams. Make sure these seals are in place. Do a search, this item is covered in the archives if you want more info.

Where was your oil leak coming from specifically, cylinder base joint, head joint, etc. Sometimes these leaks can be deceptive, the leak might be higher up on the motor but running down the back of the motor and appearing like it is a base gasket leak, cam chain tensioner leak can add to the frustration as well and not easy to spot.

[tkent02]

With only 2,500 miles I wouldn't even think about replacing the rings, unless they were damaged. Where exactly is the leak?

[derickson104]

Thanks for the bit about the metal rings for the head gasket, I did find them on the parts lists, and those are in place now, but I'll be sure to include them in future orders (sneaky buggers).

By cleaning the front surface of the engine and running it, it is very apparent that I have oil running down from the valve cover gasket, front, just left of where the vertical tensioner bar sits for the timing chain. I also have a small pool of oil which forms in the pocket to the right of the cam chain tensioner. As well, the base gasket shows slight leaking around the left side, rear stud, where the egg o-rings are. I believe this is it, though I also have my suspicions about the head gasket completely sealing, the way the bike 'seems' to burn some oil at startup, despite new valve stem seals. What this all amounts to is a nice greasy crud developing across the entire front of the motor as the oil leaks and is pulled across the front of the motor by the wind. The other suspected leaks cover the oil pan in grim, which drips onto the exhaust pipes (smells great!) whew!

Now, I've replaced all these gaskets myself, with (i thought) adequate attention to the flawlessness of the mating surfaces. After hearing this though, I'm thinking the gasket kit I used was sub-par at best. The problem with the base gasket is that I had to replace the head after the first rebuild and didn't replace the base gasket. I suspect it compressed and didn't seal when torqued again with a new head (punishment for sub-standard parts and rushing the job!)

Thus it sounds like the GS needs another rebuild and hone with new, OEM gaskets. I suspect no problems with the rings, since they are so young, though I still need to do another compression test. Perhaps they will be replaced again as well.

This is a grimy adventure gents! Any comments or illuminating past experiences from GSers who have successfully sealed oil leaks would be greatly appreciated. Thanks again to all!

[Big T]

New gaskets, yes

There's no reason to hone or put in another set of rings, since you just did it

I had an issue when I rebuilt my 78 motor that the #1 cylinder pumped oil, very badly

I had the motor apart 4 times, the head went back to the machinst twice, no change

I finally took the entire top of the engine to a friend who's a turbine machinst - he found the bore job was defective with a gouge in #1. Honed that defect out, swapped the pistons around to maintain clearances and 25k later it still runs fine

So, new rings do not need another honing, they'll reseal just fine.

In your case, I'd retorque the head and see if the base gasket leak stops. definitely replace the valve cover gasket and go from there