I have recently got my 1963 C15 running after a very long (20 year!) fallow period. It now starts and runs well up to about 3/4 throttle. After this it starts to misfire or maybe hunn (at about 50 MPH). I've checked the main jet and it is a 140 for the 375/34 carb which I think is right for the bike. I've fitted a new 140 main jet and a 150 - all with the same effect. I'm wondering if its something to do with the distributor which does seem to vibrate quite a lot! I'm really emjoying fettling my bike so any advice re my misfire gratefully received.
Hi have you checked out the distributor, my 1959 triumph 3TA did that and it was worn bushes allowing it to wobble about and throw out timing at speed
Cheer
Paul
Not a bad idea to pull the distributor and clean and check it. Mark the position first with a line from the distributor to the crankcase..
Easier to clean and set points when out, check for play in the spindle, check advance mechanism and springs, clean and oil where necessary. They are easy to take apart. Distributor Doctor has spares for them and can also refurbish but that is not cheap!
Quote from: Pauldemob on 03 Aug, 2020, 16:23
Hi have you checked out the distributor, my 1959 triumph 3TA did that and it was worn bushes allowing it to wobble about and throw out timing at speed
Cheer
Paul
Thanks Paul. I haven't done much to the distributor so that's probably where the problem lies. I'll pull it out and try to sort it.
Quote from: AdrianS on 03 Aug, 2020, 16:35
Not a bad idea to pull the distributor and clean and check it. Mark the position first with a line from the distributor to the crankcase..
Easier to clean and set points when out, check for play in the spindle, check advance mechanism and springs, clean and oil where necessary. They are easy to take apart. Distributor Doctor has spares for them and can also refurbish but that is not cheap!
Thanks Adrian. I will do all of this. Really good advice.