BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: TTJOHN on 02 March, 2017, 12:30:31

Title: A65L Starting problems
Post by: TTJOHN on 02 March, 2017, 12:30:31
Hello all just wondered if someone could put in a bit of input into a problem I have with an A65L, I've put on a Boyer Bransden ignition kit, timing is correct, I started the bike up and it cut out almost straight away, so I decided to change the carb from a concentric to a Makuni, started it up and once again it cut out just after starting, it just seems like fuel starvation, the bike has just had a rebore, new pistons rings etc, compression is good. Can anyone shed some light or give me a clues as to what the problem might be?
Answers written on a 5 note might help, if I get enough. ;)

Title: Re: A65L Starting problems
Post by: AWJDThumper on 02 March, 2017, 12:57:36
I would start by checking everything is adjusted correctly, including the tappets. When you say the timing is correct, presumably you've only done this statically rather than using a strobe at this point? If so, I would double check the initial setting.

It could be fuel starvation but a full float bowl of fuel should let the engine run for quite a few seconds. It sounds as though it's cutting out quicker than this which might suggest it's not the carb, especially since you've swapped for a Mikuni! You can always take the drain plug out of the Mikuni and check fuel flows into the carb ok.

If it's not the timing or carburation, it might be necessary to check the engine has been put back together starting with the valve timing. This is not that difficult to do on a twin but needs a timing disk fitted.