one plug black, others tan

[thumperjsa]

I have been trying to figure out why I am getting a low speed miss, at least that is what it feels like.

Like I mentioned before, I am no expert and it has been years since I turned a wrench on a car or a bike and it is coming back to me, but not quick enough.

Anyway, I pulled the plugs tonight after taking the bike on a short ride after warming it up and 1,2 qnd 4 were a tan color on the insulator. However number 3 was dark black but dry. I assume this meaning that this cylinder is running a bit rich but I am not sure.

So the next question is, where do I go next for adjustment?

I have been reading through and I am sure I am missing somethign simple, but unsure of what to do next, short of bringing it to a mechanic that would know what to do.

[Winterhawk]

Try checking the compression first before tearing into the carbs.

[thumperjsa]

Compression is low. I can't recall right now what it was on tha cylinder and I think I have ring blow by based on crankcase vent output and increade in compression from putting oil in the cylinder. I believe I was running either 100 or 120 out of that cylinder.

I hope not to pull apart and do a engine rebuild until absoloutly necessary.

I had the carbs rebuilt and tuned when I first got the bike by a shop. It ran much better after it was done. Since then I replaced the intakes because they were leaking real bad and were already repaired at least 2x.

[TonimusMaximus]

I was running 90 psi on my 3rd cylinder. I couldn't figure out why, but when I tore my engine apart, the 3rd cylinder was worn .6 mm oversized. The piston itself was still in good condition.