stripped cylinder head bolt?

[bikerfox]

I just got my '80 GS850 today, and it leaked like crazy all the way home. I get home, tryin to find the leak's source (its dripping like crazy off of the exhaust flanges) and when i poke the cylinder head bolt under the spark plug, its loose! Its all the way down in, and i pulled it right out with some resistance.

Not only that, the far left (sitting on the bike) plug is completely clean, like it was brand new! Could this be the source? And can it be repaired on the bike or does the metal have to fly?

I have been riding a GS500E basket case before this one :P wondering if i should have kept it and its driveshaft leak/blown fork seals
(though i do love having the bigger bike)

[SqDancerLynn1]

Probably why the head gasket blew. No choice but to strip the top end
We are talking about the head bolts Not the cam cover bolts Yes??

[bikerfox]

i believe so, its the one right under the spark plug on the far left. Useless without any pics i know, no working camera tonight

Its not one of the huge acorn nuts, though. Its a smaller bolt.

Bummer, how hard is a head gasket job on these?

[bikerfox]

this might help

http://www.bikebandit.com/houseofmotorcycles/suzuki-motorcycle-gs850glt-1980-cylinder-head/o/m6118sch255621

Its number 10 in this diagram.

oh yeah, i found out if the bike is leaned over more it leaks off the corner of the fins, seems to be pouring out of the recess where the inner left spark plug sits

[Big N daft]

If that bolt is stripped I don't beleive it would account for your leak unless some of the 8 cylinder head studs were stripped as well. You could probably get away with helicoiling that one without removing the head.

Also if the oil is dripping down off the exahust flanges then that would seem to me to show that the leak is actually higher than head gasket joint. Check the cam cover and also the tacho drive.

It doesn't neccesarily mean blown gasket it could be that the valve stem seals have gone and are allowing oil through, it could also be that the piston rings are stuck and allowing oil into the cylinders stopping the bike from firing and forcing the oil out through the exhaust.

[seuadr]

could your breather be clogged?

[bikerfox]

The bike runs, and boy does that engine sound BEAUTIFUL!

That clean looking spark plug now shows a somewhat lean but still ok condition (leaky, cracked carb boots, gonna change em) and with the tank off but still connected, running the bike seems to be leaking the oil from the valve cover gasket, but its quite a bit of oil, will it normally leak this much? It probably leaked a quart in 25-30 miles of riding!

Theres no smoke from the exhaust, and doesnt smell like its burning any oil through it. Even at a good load still no smoke. All the smoke comes from the oil burning ON the exhaust

Other than that, this bike is like a cadillac compared to my GS500E

i love how smooth the engine hums

[hampshirehog]

That bolt doesn't do a great deal in tightening down you cylinder head - it's a low torque spec (I normally replace them with stainless bolts and don't bother getting the torque wrench out). If the thread has gone have you got enough room underneath to slide in a 10mm nut - on some bikes you can do this and I think that's fine as a fix.

Your cam cover shouldn't leak any oil at all. You're gonna have to pull it off and replace. Be careful when removing the old gasket that bits don't drop down in to the motor and be careful torquing down the bolts that hold it on - loads of fellas on here have stripped the threads.

[bikerfox]

thanks for the help everyone glad i joined up!

Im going to order a new gasket from bikebandit (i get it overnight, even on the cheapy ground shipments, i love being 2 hours from their warehouse)

Ive made mistakes like that on cars, a chrysler new yorker is oversensitive to over tightening the valve cover bolts, cuts gaskets with ease!

Im looking forward to many miles with my new friend, and my new friends

[bwringer]

Check to see if the breather system (hose running from valve cover to airbox) is clogged. Sometimes the steel fitting on the 79-81 airbox rusts shut. This can allow the engine to pressurize and worsen any leaks.

You may have also lost or displaced one of the half-moon shaped seals -- take the decorative caps off the ends of the valve cover and take a look.

I use lifetime silicone RealGasket valve cover gaskets on 850 engines:

http://realgaskets.com/files/motorcycle.htm

You'll need the RG-GS850-G1 valve cover gasket and the RG-SBC-2 breather cover gasket.

Just PLEASE pay attention to the extremely low torque spec -- it's given in Inch-pounds, not foot-pounds. 15 inch pounds is just barely past finger-tight, but it's plenty to compress the silicone perfectly and make a great seal.




Here are instructions for fixing couple of other very common GS850 leaks, although these just seep enough to be annoying rather than the gusher you're dealing with now:

http://bwringer.com/gs/tachcableseals.html

http://bwringer.com/gs/camchaintens.html

[bikerfox]

Theres an idea, come to think of it, it does take a couple miles of riding to start leaking. Ill check that tomorrow, thanks!