left plug fouled

[Anonymous]

Well i have a 81 GS450 and it had been running perfectly until yesterday, I went out and started it, but it was only running on the right side. The left side is not firing. I have taken the tank off and checked the connections and i have spark, After playing around with it, i was able to get it to start with only being connected on the left side, it runs rough and won't idle. The plug is very wet and black. I got it running yesterday on both sides and took it out for like 50 miles thinking maybe a good run would clear things out. But this morning it started right up, but only on the right side. I have really no idea, so any ideas would be greatly appreciated. Everytime i start it the left side plug gets fouled up. Is this just a carb thing.

[KEITH KRAUSE]

Let me ask a few questions first.
Does the fouled plug look shiny black (oil fouled) or a dull or sooty black?(rich mixture)
If you let the wet plug just sit, will it become completely dry?
Do you see ANY white smoke (oil) out of the left pipe, ESPECIALLY at start up?
Do you see ANY fuel overflowing from the carb?
Are you able to do a compression test?

You say the bike ran perfectly and then suddenly had this problem? Do you mean it ran good one day and the very next day it started fouling the plug, no warning at all?
Or did the bike run good and then sit for a while before the problem started?

[Anonymous]

the plugs are shiny black like oil, there isn't any gas overflowing the carbs. When i start the bike there is usually some white smoke, The bike ran fine and maybe sat 3 days before the problem started. About a month ago there was allot of white smoke pouring out of the exhaust and i added one of those oil additives that are supposed to help stop that.

[Anonymous]

oh sorry, i don't have the equipment or the knowhow to do a compression test.

[SqDancerLynn1]

Did you check the petcock??? Install a new plug and disconnect the vacuum line from the petcock and plug it with a screw. Then Try running the bike with the petcock on prime. DOn't forget to turn it back to the ON position when you shut the motor off

[KEITH KRAUSE]

the plugs are shiny black like oil, there isn't any gas overflowing the carbs. When i start the bike there is usually some white smoke, The bike ran fine and maybe sat 3 days before the problem started. About a month ago there was allot of white smoke pouring out of the exhaust and i added one of those oil additives that are supposed to help stop that.

The only way you can oil foul the plug is a bad piston ring or a leaking valve/valve guide or seal. The white smoke is more proof that you're burning oil. When the engine is cold the oil will leak into the combustion chamber easier. This is why the plug fouling is at its worst at start up. As the engine warms up, the clearances tighten up and the oil leak decreases a little. It will only get worse.
The oil additives sometimes help, but only temporarily. Good luck!

[SqDancerLynn1]

Keith knows his GS bikes------ And if the petcock leaks into the cylinder it washes the oil off of the cylinders and can drastically shorten the life of the rings

[Anonymous]

so theres no chance cleaning the carbs would solve that? What are my options if the oil additive doesn't stop this?

[SqDancerLynn1]

It is a process of elimination to determine the problem.
did you check the petcock??????http://www.thegsresources.com/_forum...ic.php?t=21714

[Anonymous]

I went to check my petcock and it won't move, It is absolutly stuck in the on position. Now I don't know if this went out recently or not, i don't remember the last time i moved it to prime or reserve.

[KEITH KRAUSE]

so theres no chance cleaning the carbs would solve that? What are my options if the oil additive doesn't stop this?

White smoke, oil fouled plug. You have either a piston ring or valve leaking oil. This is not a carb problem.
There are several ways this could have happened. As Lynn pointed out, over time, a leaking petcock could allow too much gas into the cylinder and cause your problem. It could also be too many "dry" starts from the bike sitting between rides. Dirty oil. Parts wear out, seals go bad.
It sounds like you're already past the point where an additive can help.
You may be able to take apart the petcock and clean it up. You may have to rebuild it if you can find a kit. If the diaphragm is bad and leaking gas through the vacuum line and into the carb you may be able to rebuild it?
My petcock diaphragm was not rebuildable, you have to buy a new petcock or maybe a Pingel valve.

[Anonymous]

well i have a new petcock on the way, so after i replace that what is my next step. I was thinking getting new spark plugs and changing the oil, I was reading some stuff and some of the thicker oils would help slow the leak. Also i have been putting in new spark plugs on the left side and taking it out for a ride praying that the oil additve would magically cure everything. No luck yet though. When i put a new plug on it, it fires right up and and it runs okay, but even if i get it going to aroung 60 as soon as i have to come to a stop it goes back to one cylinder, About midway through first gear you can feel the left side fire up. Sorry for all the questions and the long notes, i just want to give all the info i have to see if there is anything i can do. Also, what about the vavle seals, is this something i can do myself, or is the bike dead.?

[KEITH KRAUSE]

All you can do is take it apart and inspect things or take it to a shop.