Re: Clutch RPM limit
The rev limiter is set at 8300 I believe. I had the same problem hitting the rev limiter and the way to fix it is with clutch weights. Do you know what size weights you have? When I bought my riot it had 4 37gram weights and it would often hit the rev limiter. I found that 2 37grams and 2 39grams weights works best for me, keeping it right at 8200rpm. But that shouldn't effect your top speed by that much maybe a few mph, but the weights wouldn't be causing a top speed of 30. Hopefully someone else has a thought on that low top speed.
As far as the backfiring goes, do you have a big gun programmer and exhaust? I've found if my programmer isn't set quite right it backfires a decent amount.
I would suggest getting figuring out which weights you have in your clutch and pick up a few 39's and see what works best for you, it's very easy to change the weights to compare everything. And also a big gun programmer should help that back firing problem