OK, here is the deal.

Late this past summer, I installed Lightning Headers on a stock 502 MPI. It has a K&N Flame Arrestor. Everything else is bone stock.

I currently run a stock 24 B1 prop and am hitting the rev limiter regularly. Even with a full bag of gas.

1. I am told I better get my ECU reprogrammed (might be running too lean).

2. I think I might try a 26 B1. I am wondering if I will be able to spin it. If not, I could lab it to gain back a few rpm's?

2000 Sunsation 288. Best GPS speed was 69.4

Any thoughts?

1. check your plugs. those will tell you if running lean or rich

2. i would also try that prop and if its too big then yes you can have it labbed to get a few RPM back. Or you can try and have your current prop pitched up a pitch to a 25 and see how it does....no sence in spending money on a new prop if you dont have to. Another option is to see if anyone would be willing to let you try one of their props and see how the boat like it!

If you were in my area here i could let ya try a 27 mirage

mlitefan - do you (or did you) have switchable Quick and Quite that works with the Lighting headers? I have a '98 502 MPI and am weighing options but want to keep the Q&Q. Oh - totally stock running a 25 Mirage Plus just under the limiter (is it 5050 RPM ???) - 22 Donzi Classic

Thanks

No Q&Q on my setup. I might add switchable tips at some point. I thought about adding cup, as was suggested by another OSOe'r as well.

Well I installed CMI exhaust and KN on a 502mpi and it was a little lean in the mid range. I installed a adjustable regulator and just bumped the pressure a couple pounds. No problems. Gained a little punch but did not gain much if any on top end.