'82 450L, no compression

[Eli]

I've had a minor oil leak on this bike ever since i purchased it. Nothing major, a few drops every time i'd ride. I'd typically do anywhere from 150-200mi a week, sometimes more, oftentimes highway. It took a quart every few weeks.

A couple weeks back, something apparently went very wrong. All the oil blew out pretty much at once, best as i could tell from somewhere high on the engine. I have the Clymer manual, all the necessary tools, and some mechanical experience, so i ordered a new valve cover gasket, head gasket, and some of the minor parts i knew i'd have to replace (half moons and such). I was able to tear down the engine head and replace the head gasket, then reassemble the head and replace the cams. The valves were not removed at any point. I washed most of the inside in parts cleaner, but carefully wiped out the pistons. I found no evidence of cracks or scoring in the cylinders. I have not yet removed the pistons to inspect the rings.

While replacing everything, i'm pretty certain i put the timing marks back correctly ("T" for right piston to top-dead-center it, then the "1", "2", and "3" marks on the camshafts according to the manual), got the cam chain tensioner in correctly, and had the head seated over the new gasket snugly.

I have no compression in the right cylinder, and only about 30psi in the left. I checked those numbers with two compression testers. I have not done a wet test, but will try to do one tomorrow and post the results.

I noticed something else, though- when replacing the camshafts, the shims now have well under the specified clearances. They're all 2.50mm's and higher, so i'm gonna swap in some 2.00s on Tuesday when the local parts shop opens and get some actual measurements, but for now, the spare 2.20 i have around has almost no clearance on any of the cam lobes (<.025mm). Could these be the root of my problems?

Also, i have a sneaking suspicion i may be one link's worth of turn off timing, but i'm not 100% certain about that. According to the manual, the "1" arrow should point just under the gasket surface, but i have it aligned pretty much even with the edge. If i keep the "T" mark in line, should i rotate that "1" arrow another link down until it truly is pointing below the edge of the head, even though that makes it noticeably lower?

 

[Nessism]

Sounds like a number of issues here...

For one, you should always pull the cylinder and replace the base gasket each time the head is pulled otherwise you have a very real chance for leakage, either immediately or in the near future. You should also pull the valves out of the head, inspect the sealing surfaces, and replace the valve stem seals.

The shim situation you describe sounds strange. The existing shims are 2.50+ but you get no clearance with 2.20's? If that's correct the valves might all be burned to crap. Also, the thinnest shim is a 2.15, there is no such thing as 2.00's.

Honestly, I'd pull the head back off, pull the cylinder, and start from scratch. You should inspect the rings too while the engine is apart. Short cuts are long cuts on these old bikes and you are learning the hard way.

 

[Eli]

I kinda worried that it might be valves. Sounds like another week+ of waiting for shipping of parts.

Could the valve problem have been caused by the sudden loss of oil? Is it simply a routine problem? Bike only has about 15k mi. Is it likely connected to something else, that i need to check?

A relevant negative i forgot to mention, just in case- there was no unusual smoke coming from the exhaust.

Also, thanks.

 

[tom203]

Odd to lose all that valve clearance- you sure you got cam bearing caps in original orientation ? Do the valve/seats look pitiful?

 

[Nessism]

How and where did the oil "blow out"?

 

[Eli]

@Tom: I need to rent a valve removal tool to check them. I'll have to get back to you on that.

The oil began leaking while riding. As to how/where, i can't say i'm certain. One moment, i'm moving along, doing okay... the next, oil is all over the outside of the engine. I mean everywhere, up high, front, back, low, but with no smoke coming out of the exhaust, at least. It also ran back and seemed to get on the rear brake. I pulled over immediately and shut it off.

 

[Nessism]

Some info on how to remove valves here using ordinary tools...http://members.dslextreme.com/users/bikecliff/images/valve_replacement.html

Best to pull the top end down all the way to the crankcase. Inspect everything then go from there. For gaskets, only use original Suzuki gaskets. You can often find Suzuki gaskets on ebay for fair prices.

Good luck

 

[Eli]

I feel like i should have thought of that myself. Easy enough to make. I now have the clearance problem settled, as well. Apparently, when i took the tappets out and sprayed aerosol parts cleaner throughout the head, i removed most of the gunk... but i forgot to cover the valve holes, or clean the insides of the buckets, or something, and had re-accumulated a decent ring of grit in there. Next time, i'm taking the thing to a buddy's professional garage to work on it. He keeps his place spotless.

While i've got your attention though, i do have two other questions. While reading through one of these forums, i seem to recall a post mentioning that you shouldn't put gasket sealer on the valve cover or breather gaskets (i definitely did NOT think about putting it on the head gasket, no worries). I can't find that post again even with an advanced search. What's your take on sealing gasket surfaces?

And last, is there any way to do a hand-crank compression test on these bikes, or is that doomed to failure?