Poor Cold Starting

Hello to all - got a problem with the 2004 T100 that I recently bought. When I picked it up it took ages before the engine ran well enough to put the choke fully home but I just thought as the bike had been stood up for quite a while it just needed a good blast which I gave it on the 30 mile trip home. Since having it my workshop I have carried out a fair bit of maintenance including swapping the Norman Hyde Togas over from my 2001 Bonnie and changing the main jets to 120’s and also taking out the pilot jets and cleaning them. Have also fitted an AI removal kit and done the crankcase breather mod.

However the poor starting remains as before - the bike fires up on the near side cylinder then after about 20 - 30 seconds the offside cylinder kicks in I have to then leave it for around 5 mins running with the choke out before it will Rev cleanly and after that it runs fine ...

Just can’t think what could be causing this and wondered if any of you have had the same issue ?

 

Good morning Wire-Wheels thanks for that suggestion and no I haven’t I just cleaned up the old ones and re set the gaps but admit it’s one of the things I had been thinking of trying next...

 

Ok just tried a nearly new spark plug from the other Bonnie and no difference

 

Thanks Callumity I am now also suspecting contaminated/old fuel as I think the bike sat for a long time without being used - when I took off the float bowls to change the main jets I saw a bubble of something odd in the bottom of one of the bowls which may have been water now I come to think of it. The previous owner filled up the tank for me when he got the MOT done but perhaps it would be wise to drain all the fuel out and re fill with fresh, I just tested the offside cylinder spark by firing up the bike with the offside plug still in the cylinder but put the HT lead on a spare plug and the spark look pretty consistent. When I took the other plug out of the O/s cylinder after the spark test it was wet with fuel but I suppose if bubbles of water had condensed inside the tank during standing there may be a whole load more in there...

 

Ok bike back together now and went for a test ride this evening. From cold still got no ignition on the offside cylinder For a few seconds then it kicks in Ran it on choke fast idle for about 5 mins then took to the road.

So goes like a rocket except a cough and splutter when accelerating from low speeds and also when blipping the throttle at tick over once hot - it’s like there is an issue during the transition from Idle jets to main jets. I have fitted 120 mains and the isles have been cleaned and are standard size.....

 

“Isles” = Idles!!

 

Hi Callumity - that is true but I’m sure it’s connected with the starting on one cylinder issue - I feel a carbs removal job is on the cards as even though I’ve removed and cleaned the pilot jets there could still be some crap intermittently blocking the jet drilling. Can’t see a way to spray carb cleaner into those drilling’s in the lower part of the carb inlet without removing the rubber Air box connectors and don’t think that will give me enough room to access those drilling’s even then ?

Chris - yes checked the ht leads with a pair of those see through lead testers and spark good on both cylinders even when offside cylinder not firing - have put new plugs in and no difference...

 

Yes goes like a rocket after it stops farting about - fitted at 18 tooth front sprocket too!

Ok Callumity that sounds a good starting point before taking them off completely- would it be a good idea to undo the inlet manifold bolts too?