Help - Cylinder 1 spark plug black soot
Posted: Mon Oct 19, 2020 3:29 am
Hey guys.
My '97 XJ600S (UK model) has a bit of an issue. Spark plug on cylinder 1 is black and sooty. The rest look perfect, but...
When I got the bike a few months back it was a devil to start, but once coaxed to life it runs / rides perfectly well.
So I bought a good carb / jet cleaner petrol additive and have covered 2 full tanks with it in now. When I pulled the plugs again to check them, plugs 2, 3 and 4 are fine, a nice tan golden brown, which is great because before the carb cleaner additive was used they were all various shades of black and sooty (except plug 4, which was bone white). So the additive seems to have done some good.
Except in cylinder 1. It remains black and sooty and the bike is still reluctant to start (although has got slightly more willing).
So now I'm wondering about idle jets and main jets. I do have a free-flowing air filter (similar to K&N), plus I have a 4 - 1 full stainless exhaust system with noise dampening baffle, so it does still have a little back pressure (it's not a full straight through race exhaust system).
So any suggestions for things I could check out on cylinder 1?
My '97 XJ600S (UK model) has a bit of an issue. Spark plug on cylinder 1 is black and sooty. The rest look perfect, but...
When I got the bike a few months back it was a devil to start, but once coaxed to life it runs / rides perfectly well.
So I bought a good carb / jet cleaner petrol additive and have covered 2 full tanks with it in now. When I pulled the plugs again to check them, plugs 2, 3 and 4 are fine, a nice tan golden brown, which is great because before the carb cleaner additive was used they were all various shades of black and sooty (except plug 4, which was bone white). So the additive seems to have done some good.
Except in cylinder 1. It remains black and sooty and the bike is still reluctant to start (although has got slightly more willing).
So now I'm wondering about idle jets and main jets. I do have a free-flowing air filter (similar to K&N), plus I have a 4 - 1 full stainless exhaust system with noise dampening baffle, so it does still have a little back pressure (it's not a full straight through race exhaust system).
So any suggestions for things I could check out on cylinder 1?