Misfire on Triton

[A65rider]

I'm trying to run in my recently rebuilt Triton engine but am being plagued by a misfire in the RH cylinder. I've changed plugs having found one brand new NGK plug to be faulty but its not completely solved the problem. The bike has Lucas Rita ignition with 6V PVL coils and Amal Mk2 concentric carbs. The engine has a 8 valve Nourish head and 920cc barrel. I've also noticed that when I switch on the ignition the ammeter goes into the -ve - is this normal. Thoughts welcome

[mini-me]

 -ve Normal because you are using current to charge the coils.

Electronic ignition is a nightmare, I gave up using it years ago, but I'm sure there is help coming.

[Grunt]

I’ve got Lucas Rita electronic ignition on my Rocket Three. I’ve not had it running for years but the memory of it misfiring has still remains with me. All it was was the rotor Furring up with ally corrosion. I’m not sure it’s likely to be this though if it’s  a recent rebuild.

[iansoady]

I'd start with the usual - swapping components from one side to the other to see if the problem moves with them. I don't know about RITA but Boyers were notorious for problems with the connections to the pickup coils, especially on Commandos. But that showed up on both cylinders rather than just one.

[Rex]

Having said that, with a Boyer a low battery voltage shows as a misfire on one pot first, although having done so much work on the bike you must have checked the battery condition and charging?

[A65rider]

thanks for all your comments. The battery is brand new although due to the size I wanted it is only 5Ah, it does normally have over 12.6V though and the ammeter indicates its charging when running. Re the -ve when I switch on I can understand an initial period of charging the coils but not continuously doing it. I'm going to change out the circuit board on the Rita ignition with a new one from Rex's Speedshop and then probably move onto a new 3 phase alternator and voltage regulator. Anybody any thoughts on carbs and how to check if jets are too big / too small. Rgds

[mini-me]

Carbs won't cause a misfire.

[chaterlea25]

Hi
I would hook on a decent sized battery and see if the performance improves ?
I know guys on the BSA C forum have had problems running with small AH batteries

John

[largeviking]

Had similar problem on my Triton, it has a T140 top end with twin 930’s. Tried changing plugs, leads, coils, voltage regulator, needles, set float heights too, all to no avail. Came to change jets and noticed one had come loose, tightened it up, problem solved.