#2 & #3 plugs still fouling...

[rpgoerlich]

79 XS1100SF has 54k on the clock. Finished adjusting the valves. Compression was 165-170 on all 4. Carb floats re-checked today and re-adjusted them to 27mm. figuring I had a rich issue. Carbs are synced. Replaced Coil feeding #2 & #3. Both coils check good now with new 5k plug caps. Had found wires on both pickup coils broken, Re-soldered them and they check good now. I took a look at the TCI and re-soldered all the connctions for the spade connectors. It has good spark on all 4. Problem still shows up above 4k rpm as a miss. Inspecting plugs, #2 & #3 plugs are both severly carboned up.

From another post, It looks like I could swap pickup coil inputs at the TCI and see if it moves, Correct ? If it moves=bad pickup coil. If it stays the same=bad TCI. ?

You say you swapped out wome other ignition coils, and still have no spark on 2-3 coil. The next thing is to swap the PICKUP COIL wire connectors/inputs going to the TCI, IF the problem moves to the other igntion coil, then there is a problem with the Pickup coil, either the wires, or even a coil going bad. But if the problem stays with 2-3, then you've isolated it to the TCI.
T.C.

Thanks

[Ken Talbot]

Look for another pick-up coil wire break. Just because you found one doesn't mean there can't be another.

DAMHIKIJD

[rpgoerlich]

Yes, I did. I removed all of the wrapping and tugged on them all, all the way to the TCI connector.

[Ken Talbot]

It is more common to have multiple breaks inside of the left side engine cover, where the pick-up coils are. The trickiest one I ever found turned out to be under the crimp fitting just before the wires exit the cover.

JAT

[TopCatGr58]

Hey Richard,

What I posted was a static test only. IF you want the bike to run, you'll need to swap the plug wires, 1-4 to 2-3 and vice versa otherwise it'll be 180 out and won't start! You DID put in NEW PLUGS didn't you, not just cleaned up the old already fouled ones??? Even after cleaning, they can still foul more easily than NEW and give you false info!
T.C.

[rpgoerlich]

Yes, new plugs. Took it for a run today, same thing. Everything checks out resistance and voltage wise. Seems to miss when I put a load on it, above 4k rpm once it's warmed up.

I have a pickup coil off of an F I'm going to try. I'll have to make a new connector for it as it's different than the one on the SF.

Hope this will rule out either the pickup coil or the TCI.

[TopCatGr58]

Hey again Richard,

The replacement coil, is this another OEM, or are you using aftermarket coils?? Being able to see spark on the plug doesn't necessarily mean that they are able to spark in the engine! Before you swap in the PU coil, try swapping the ignition coils, 1-4 for 2-3, and see IF the fouling stays in the middle, or moves to the outside cylinders. IF stays in the middle, then it's NOT necessarily the electrical, more likely carb. But if it moves to the outer cylinders, then you've moved the GOOD COIL to the inner cylinders, and the replacement bad one to the outer. Unless you do have a bad PU coil, but I thought you had already tested for that. Isn't electrical stuff fun!?

Also, above 4 k is where you're getting heavily into the mains. JAT!?
T.C.

[rpgoerlich]

Replacement coil was OEM. Thought about swapping coils/wires today but they were too short to reach the outer plugs.

Yea, I had tested everything, coil resistance - ok, pickup coil resistance - ok, Voltage ok at TCI.

I pulled down the carbs again yesterday just to verify the jets were stock, needle setting was center on all 4, as the PO had a homade filter in it which was basically a K&N. While I had them out I reset floats a little higher(27mm) to lower the fuel level in the float bowl.

Thus the reason for swapping the Pickup coil as I have another. Just to see if I 'm having some sort of breakdown(in the pickup coil).

It's wierd. #1 & #4 plugs are just right, nice tan. While #2 & #3 plugs are severely carboned up. Actually having a little afterburn in the pipe from unburned fuel.

Probably be a couple weeks before I can get back to it as Spring break is next week. Got a kitchen pass for a week off at the fishcamp. Fishing with my son and his buds. Hopefully we'll have some good weather to get offshore for a few days.

[randy]

You might also want to check the gap at the pickup coils. If the gap is way out, you may never find the problem swapping connectors! The gap should be
.7 mm. The pickups only generate a very small signal and the smaller the gap the better the signal. I have mine set to .5mm. It's a pain to do, cause you need to remove the timing plate and re-install an 8mm bolt in place of the original bolt, or re-use the original with a bunch of washers.

[rpgoerlich]

Yea, double checked the pickup coil clearances Sunday...

[dbeardslee]

When you say you replaced a coil, do you mean with a used oem or a new one? Reason I ask is because, if it's used, the integral high tension wires are probably getting pretty long in the tooth after 30 years. When I replaced my coils I thought I would keep the old ones just in case. I went to put them in a coffee can, and when I bent the wires they snapped in two! There's a thread on here somewhere that shows how to graft new high tension wires into an old coil. Might be something to look at after diagnosing as per Ken/TC/Randy.

What kind of plugs are you running? I've found the ngk iridiums (bp6eix) to be as close to foul-proof as they come, but a little pricy.

[rpgoerlich]

Had a set of NGK bp6es in it, swaped them out for some Autolite 63's.

Here is a pic from tonights run which looks a little better on #3 and worse on #1 & #2. L-R = 1-4.
I guess I'm gonna have to take another look at the carb float height adjustments... It's missing up around 5.5krpm now.

[dbeardslee]

The condition of the plug second from the left in the photo looks awful sooty for one ride. I'm wondering if your valve stem seals are leaking, which can foul 'em pretty quick. Do you have access to a colortune plug so you can see what's going on in the combustion chamber?

[DiverRay]

Richard,
When you fixed the pickup coil wire, did you MAKE SURE The colors didn't get swapped? If you switch the blue for the orange on one coil, it WILL act strange, and not run properly!! DAHIK

[rpgoerlich]

Yes Ray, Wires stayed same on pickup coils.
Looks like rain this weekend, I may get a chance to look at float bowl levels this weekend before I pull the carbs.
I did try and colortune it but had too much fuel in 2 & 3 at the time, with some after burn going on.