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ST Poor running - self inflicted

Posted: Sun Nov 15, 2009 5:19 pm
Author: Mick Hayward
Hi Guys

I thought I'd post this in case anyone else has the same problem.

Got my ST running several weeks ago and it was fine. This was I might add without the air cleaner, which was duly fitted when found. The bike was still okay then disaster. 10 mile out and we had a missfire which got steadliy worse. Nursed it home and removed plugs 1 and 4 were carbon fouled. Spent the next 2 weeks off and on trying to find out what was wrong. Changed plugs, Removed air filter weakened pilot screws. Nothing changed the plug fouling. Checked for spark, not fantastic but there. Gave up in dispair today and went back on the forum for a search on poor running. Found a mention on suppressor caps and then the penny dropped. I had inadvertantly caused the problem myself. As the HT leads are a permenant fixture in the coils the previous owner had cut the leads and inserted the old style WD (with a crows foot) suppressors to facilitate fitting silicone leads with permenant caps. These straight caps looked pretty awful on number 1 and 4 so I cut them off and fitted 2 NGK right angle caps, (surpressed). Forgetting of course that suppressors were already in line further back towards the coils. As I said bike ran well initially and then went to rats. Reading the forum reminded me of what I'd done. So I rushed out to the garage, unsrewed the ngk caps and pushed the leads directly onto the plugs 1 and 4. Pressed the starter and hey presto it burst into life. Runs as sweet as it did before. Problem solved. What a prat. So it goes to show you can always find help on the forum and don't forget the old adage if somethings gone wrong ask yourself what have I done before going off at a tangent.!!!!!! And dont fit 2 surpressors in one HT lead

Cheers all.

Mick

Posted: Sun Nov 15, 2009 6:38 pm
Author: mikey
Live and learn mick glad you got it sorted though

Posted: Sun Nov 15, 2009 6:49 pm
Author: Mick Hayward
Hi Mikey

You certainly do. Buts its worth persevering, you do get there in the end. Doesn't help when you shoot yourself in the foot though.

Mick

Posted: Sun Nov 15, 2009 8:29 pm
Author: Garn 1
Mick H, thanks for that explanation. I used to often use that "Surpressor" method of joining the old HT leads from the coil to new leads and still using the original surpressor caps. I now use new coils and discard the 30 odd year old coils, albeit, they still worked.
RegardZ.

Posted: Sun Nov 15, 2009 8:52 pm
Author: Mick Hayward
Hi Garn

I don't think it will be long before I go down your route as well. I need to save up some money first.

Best wishes

Mick