Triumph Triple 900 Blues

odinz · May 20, 2017

Hi there ,heres a doosey for you all.Ive had a reaccurring miss on no 3 pot since Ive brought bike.
Ive stripped carbs had them ultra sonicly cleaned.Balanced and put back on.Ive had head off ,found lots of carbon build up on no 3 pot so cleaned and re seated valves.Normal compression has returned.Ive checked coils and leads replaced plugs,new petrol filters.Finally I reshimmed re seated valves.....Put it back together and lo and behold bloody miss still there.....It starts runs on 2 cylinders and once engine reaches say 2-3000 revs 3pot comes in and engine runs clean as it should ,drop revs back down and 3 pot disappears again..Im at a loss???any ideas?

dilligaf · May 20, 2017

Hmm could call it a Bonneville

Sorry mate sounds like a strange one though
Can you swap parts over to see if you can move the problem to another cylinder?
Plug/leads/coils?
If the problem moves that should tell you where the fault is

Oldyam · May 20, 2017

Only Fault I ever had like this was on an 79 R100RT but was the other way around ran fine at idle but went down to one cylinder at about 3000 rpm, checked everything without finding the problem eventually turned out to be a faulty resistor type plug cap failing under load.

I personally would change the lead and cap for new parts just to be sure

odinz · May 22, 2017

Well after all that the bike rins spot on now.Got me what happened only thing I ended up doing in end was twisting petrol petcock around a few times ,syarted it to show a friend the problem and its running perfect?????
Been for a blast yestsrday and still running good.Thanks for the help chaps.