Fouled plugs

[Guest]

I have a 1980 gs850gl it is fouling plugs #1 &#4 while plugs #2 &#3 are good can somebody tell me why ?

[fastbysuzuki]

I have a 1980 gs850gl it is fouling plugs #1 &#4 while plugs #2 &#3 are good can somebody tell me why ?

1&4 set too Rich, worn cylinders, incorrect ignition timing,
its a matter of illumination really when you say fowling do you mean black sooty oily? Or maybe metal debris?
if you have a compression gauge take out the plugs and measure each cylinder not forgetting to hold the throttle wide open whilst turning it over via the starter and report findings on here.
not saying your cylinders are worn but it is a starting point.

[ceh3523]

Plugs are black sooty , how do I lean out 1 & 4 ?

[Steve]

Note that 1&4 plugs are fired by the same coil. Might check its performance, as well.

How to lean out the carbs? Which circuit? There are four major circuits in the carb. You will need to start with some fresh plugs, then do what is known as "plug chops" to determine where the problem is.

First, start and warm up your engine with your current dirty plugs. Put the new plugs in, turn the idle up to about 1500, let the engine idle for a couple of minutes. Take the plugs out, check the color. If they are still good, your PILOT circuit is good. Next, find a road that has a slight hill. Hopefully it has someplace near the top where it is safe to pull over and stop. Start at the bottom of the hill, 3rd or 4th gear, half throttle, hold the throttle in that position, DO NOT MOVE IT. A 30-second run might be enough, a bit longer is better. If you run out of engine speed or room on the road, hit the kill switch, pull the clutch in, coast to a stop. Pull the plugs, check the color. This checks the NEEDLE jetting. Finally, on the same hill, or a steeper one, do the same thing, but a FULL THROTTLE. Again, while still holding full throttle, hit the kill switch, pull the clutch, coast to a stop. This does not have to be at, or near, the redline, as long as it's full throttle. Choose a gear that is high enough to allow you to hold one gear without shifting, but also low enough to keep your road speed somewhat reasonable. This will check the MAIN jetting. If you have problems with jetting, they will show here. The fourth circuit is the enrichment (starting) circuit. Usually hard to keep it on long enough to foul plugs.

One final question: are the plugs all the same? If someone had installed a couple of 'colder' plugs, that will also show as fouling.

.

[ceh3523]

Yes plugs are all the same, how do you check the coil ?

[tom203]

Yes plugs are all the same, how do you check the coil ?

have a read here...

http://members.dslextreme.com/users/storagecliff/images/electrical_odd-n-ends.html#A17

be suspicious of the spark plug caps.... they corrode and give reading errors