the rear bearing design.

Is that it?

from asking that same question to a Factory driver.. yes thats it.. well the case is different to fit the new rear bearing.. but i was told its practically the same engine..

Don't know the benefits of the rear bearing design though

Thanks for the info, any tips on breaking in a btts then?

if you broke in an engine before and you had good life on it .. use that method.. as long as the engine was a Novarossi.. :-) .. but look at the break in bible that's what i always use..

think i got my answer..

Can some of you tell me the performance and runtime difference between the keepoff 7 port and the keepoff 4 port or btts.

No problem, glad I could help. After buying a 2096 pipe I saw an increase of a good 2+ minutes in run time over the 9901 it replaced. I actualy was able to launch harder out of turns too because the low end became slightly softer and didn't produce excessive wheel spin. easier on fuel, easier on tires, and easier to drive fast. If you get a chance to borrow a 2096 try it out, you won't regret it.

I will be running a Keepoff 7 port in buggy, should I go 9901 or 2096?

Yes the main difference is the rear bearing and the case design for the Keep Off base engines.

The Keep Off has slightly more top end over the BTTs WC.

Glenn

I been running a keepoff 7 port in truggy with a 7mm restrictor, 9901 w/41021 header and it's an animal. In buggy I would suggest running a 6mm restrictor, 2096 pipe w/ 41012 pipe/header combo.

I would run a 9886 or 2052 pipe but the header you have is good.

Thanks man..

I'll definitely find a 2096 to try.

I've got a 2096 pipe only ran in practice one time pm me for price!