blew cylinder head plug?

[Randy Knowlton]

I started the bike (81 GS850L)tonight hoping to go for a ride. It was idling fast on choke for about 2 minutes and I started to smell hot oil. I looked in time to see oil running out of the r.h. exhaust cam cover. I shut it down, took the cover off, and the half moon rubber head plug was completly out.

I have put about 100 miles on it since adjusting the valves, new gasket, head plugs, etc.
I checked the breather tube and it was not kinked. How could this happen? could it have just worked its way out? the other 3 look good.

HELP!

[Nessism]

Did you glue them in place? Threebond non hardening sealer is good stuff for this type of application (sold by all the major motorcycle OEM's).

[mark]

I've put a couple of sets in mine and never had that problem. Some put theirs in backwards to avoid that trouble as well as the sealer.

[Jethro]

Can't speak for the 850's, but the factory manuals I have for my 1100's call for the use of sealant at the plugs and VC gasket. I use the grey RTV very, very sparingly. Almost so thin you can barely see it. After 8k miles when I usually do my next valve adjustment, the gasket and plugs peel right off with all the sealant all in one swoop.

Never had a leak or a blown cam end cap.

[SqDancerLynn1]

I got some of the aluminum half moon seals for my next project, they look very nice. I'm sure a very small dab of silicon will be needed. I use a dab of silicon on the rubber 1/2 seals too. With silicon more is not better

[Suzuki mad]

I've found that the new ones are larger than the used ones and once the engines been run they stay right there. No silcone or seleant.

When you did the top end service one may have been loosened or moved hence why it came out.

Suzuki mad
1981 GS1000ET
1983 GS(X)1100ESD
2002 GSF1200 K1.

[49er]

I got some of the aluminum half moon seals for my next project, they look very nice. I'm sure a very small dab of silicon will be needed. I use a dab of silicon on the rubber 1/2 seals too. With silicon more is not better

I've done the same. They are extremely well made.
I fitted the Ali half moons on my 850, with a small amount of Loctite 518 Master Gasket between them and the mating surfaces on the head. The flat surface that mates to the gasket, I leave without sealant. I haven't had any leaks. I do cover both faces of the cam cover gasket with a thin covering of grease. This softens the outer surfaces and promotes a better seal. You can then re-use the gaskets after each valve clearance check as they don't become attached to the Ali surfaces.

[Randy Knowlton]

I used a small amount of three bond 1104 around the plugs, I'll see if I can loosen the cover enough to re-install and see what happens. Otherwise I suppose I'll have to totally remove it and re-seal those areas.
Wouldn't you know it, Its about 70 and sunny right now!
Randy

[AOD]

To the top with this post...I just had the same thing happen to me on my 1100.

One of the plugs pushed out when I torqued the valve cover down, so I had to loosen everything and reseat the plug. When I went on my test ride, BOTH plugs fell out, sending oil everywhere.

I used Yamabond on the bottom side of each plug.

Thoughts on putting the plugs in backwards? The other two plugs stayed in the bike when I changed the gasket, so I left them alone. I'm hoping they continue to hold...

~Adam