nc29 running problems

[dan123]

hi i have a 92 nc29 and it appears to only be running on 3 cylinders. when starting from cold the bike is gutless until it warms up then seems to ride fine. on a cold start i checked the temps of the downpipes and cylinder 2 was a lot lower than the others. i left the bike to idle for some time and noticed cylinder 1 was at 260°C, cylinder 2 at 80°C, cylinder 3 and 4 both at 180°C when revving the bike cylinder 2 does raise in temp and feels fine to ride. any ideas what could be causing this?

[cbr400rrn]

Are you using a tiny bit too much choke and flooding it?

[dan123]

them readings where taken today and i didnt use the choke at all

[dunkenb]

Probably blocked pilot jet on that cylinders carb , had the same on mine .also check the O ring on the mixture adjusting screw, it can perish and suck in air.

[dan123]

what size are the o rings on the pilot screws?

[mattiec321]

I second the pilot jet theory and when were your carbs last balanced?

[dan123]

only just balanced the carbs and it seems to have sorted the issue out. cylinder 1 and 4 downpipe temps are now about 200, cylinders 2 and 3 about 180.