Scooterotica

Coming back from Bridlington, started to have misfires between 4000-4500 rpm that caused loss of power, almost like being massively over rich. If I dropped to a lower gear I could rev through it and above those revs and below it was OK. But it got worse on the way home to where it cut out a couple of times, but re-started on first kick. Did change plug and no difference and plug colour looked perfect on one I changed and on the new one when I got home. Also always fired up straight away all weekend and on the way back home.

When we stopped to fuel up and the engine cooled down, the problem didn’t manifest until a few miles later, when the engine warmed up. This suggest to me that it could be the coil or pickup on the BGM stator.

This weekend, I’ll do plug chops around the problem rev range to discount jetting, then probably change CDI unit and then stator.

Anyone else had similar problems and found the cause, because I hate taking off those runner boards. I know there are only three fixings, but for some reason it becomes a mental barrier.

Typical of worn carb parts or stator issues. Unfortunately, stripping to inspect is your first move.

I recently had very similar issues as yours and it turned out to be a worn carb needle. I changed everything electrical 1st. It's worth checking the carb 1st I'd say.

I';ve got same prob which can only be erradicted by leaning to dangerous limits . tried different pipes, carbs & Cdi's but to no avail, gonna try stator but i believe the issue to be deeper than that.

similar happened to me but a bit higher up the rev range, turned out
to be the l.t coiled a reading on your stator wires