all 4 plugs fouled; ideas please

[trispeed]

12.7 and over 14 when running

[chuckycheese]

Good

Well, then, that certainly can't be the problem!

[myk65]

I have a 1982 GS1100L with 51,000 miles... compression is 150 every cylinder. Does that sound like it is nearing the end? It does have a vibration at ~3200 rpm and is somewhat noisy; but from what I've read that is normal for these GS'?

Do a compression test. I about guarontee you have weak piston rings. 48K is definately near the end of an engine's top end lifespan.

[trispeed]

125- 185 is in spec, 100 is the service minimum.
; i 'm looking for insight. I have checked and re- checked and re- checked all the obvious. I also replaced the ignitor with a used one,no luck, I just replaced the coils with dyna items, no luck.
I have good compression, clean carbs with stock jetting, clean air filter,new coils, good battery and charging system. ???Any ideas, thanks.
It won't even start at all now, though I have lots of fuel and a small spark. what else in the ignition system could explain small spark?
what could go wrong in the carbs that would flow way too much fuel through ALL of them, if the spark is actually OK?
Thanks.

[flyingace]

Well, then, that certainly can't be the problem!

The issue is the voltage drop between the battery and the coil lead. Does anybody know if there's a reason it should be almost 2 volts below the battery?

[49er]

Try checking the rubber inlet on your airbox in case it is crushed or has a piece of plastic or paper sucked into it. This may cause an over rich condition and cause all plugs to foul.

[trispeed]

can someone with experience please tell me if 10.6 volts at the ignitor connector and at the coils is the problem. I have 12.7 at the battery and the starter solenoid.All of the other obvious stuff I have checked 3 times. All of the obvious stuff; there's no mongoose in the airbox, the battery isn't weak, the charging system is up to spec; the compression is up to spec, the carbs are clean and jetting is stock, the exhaust is stock, the plugs, wires and coils are new, HELP!

[nabrams]

10.6 volts at the coil is a bit low. More than 2 volts getting lost on the way to the coils is definitely not normal.
Now, just for a sanity check: Jump your bike up to a car battery (car engine must NOT be running).
Start the bike up.
Is there any improvement? If yes, that means the extra current from the car battery is overcoming whatever current draw is robbing those 2 volts from the coils. The current draw may be dirty/loose connections (perhaps in the ignition switch - where the key goes - see other posts regarding this). You need to fix that 2 volt drop. Typically there would be a 0.5 - 0.8 volt drop for a bike with fairly decent electrical connections - see other posts.

[rustybronco]

The choke linkage holding open? common to all.

[mark]

Air screws turned all the way in? I did that one once.......

[arveejay]

You say it will foul the plugs instantly, without the filter it's better but will still foul out. You've eliminated the intake as a problem. The only way this could happen is if the floats were set too deep and it was pulling raw fuel instead of atomized fuel, or if your choke is not releasing, or if your float valves are not shuting off the fuel flow, or orings around float valve leaking, or your airscrews are set way to rich(set them to 1 1/8 turns out from bottom), or the carbs are not getting atomizing air because of a blockage and is pulling raw fuel, try these first. Unless the bike was ridden every year for the last 25 years, the carbs will need seperated, stripped, cleaned, and fitted with new O rings, before it will ever run right. Someone before you might have drilled the jets to save buying new size jets. Do yourself a favor and get OEM filter for the airbox. If the carbs were clean, factory jetted, floats to specs, and airscrews set right and working properly, you'd be running lean and you would be in rejetting hell by now.

[chiphead]

Make absolutely sure ALL the choke plungers and choke linkage is allowing the plungers to fully seat.

[gs54]

My guess is that he needs to turn his aie jets up some, I myself would try that, Just a thought.

[BadBillyB]

can someone with experience please tell me if 10.6 volts at the ignitor connector and at the coils is the problem. I have 12.7 at the battery and the starter solenoid.All of the other obvious stuff I have checked 3 times. All of the obvious stuff; there's no mongoose in the airbox, the battery isn't weak, the charging system is up to spec; the compression is up to spec, the carbs are clean and jetting is stock, the exhaust is stock, the plugs, wires and coils are new, HELP!

I can tell you from experience, that 10.6 volts at the coils with the engine off/key on, is very acceptable. This will give you over 12 volts with the engine running.....Your compression is a little on the low side. If it were mine, I would pull the valve cover and make sure the cam timing is correct. If its off one tooth, it can wreak havoc on your fuel mixture and compression. Also inspect/change your engine oil as its probably full of fuel by now....Cam timing will affect all 4 cylinders the same......My GS1000, with VM carbs, runs so rich on the bottom end, that it is right on the verge of fuel fouling the spark plugs. I have narrowed the problem down to worn out needle jets and have yet to replace them.........BadBillyB

[flyingace]

I was looking if anybody knew why the coil lead wouldn't be the same voltage as the battery. I'd measure my own bike, but I'm too lazy to take the seat and tank off. It would be a good piece of info to have.