FYI: I've never run or tested without flappers, so I never thought about it ...at all.

Learn something new everyday...thanks....

Edit in: and yes, mufflers can effect your 'tuning lengths and etc' also.

SB, thanks for the reply in the middle of a busy day. Sucks having to work on a Saturday. Hope you enjoy the rest of your weekend.

I'm dropping it in tomorrow. Going to play with it a little more this evening, and decide which collector to use. Gotta say the silent choice ones with the 4" extension pipe running through them are looking pretty promising.

My 525, which has a "bigger" cam, has been running fine for years with the CMIs and silent choice diverters and 4" tips with internal flappers. The Y pipes are kind of a safety feature if any water gets past the flappers since it will run down the Y pipe instead of going over the hump.

a misadjusted rocker will cause reversion..like i stated eariler i would not like the angle of the holes the water is coming out of..my gils were like that and i changed them and now the water exits towards the rear and no reversion..

Bud, what did you put the cam in at?

Cam was installed straight up. According to the cam card, the exhaust valve closes "-3.2* ATDC". So I guess this means it closes 3.2* BTDC, right?

Just as a note, that must be timing at .050" lifter rise. Seat (,004" or .006" depending on manufacturer) will be always be ATDC.

Look at cam card again and post what the LSA, ECL and ICL is. This will tell us if the cam , if installed per card, is advanced or not.

Actually, forget that. Give us all the specs and tell us how you installed it (degree wheel and where you set to or just dot to dot) and we'll tell you if advanced or neutral or retarded.

The more u advance it the less it will revert. When the chain stretches it will advance a couple degrees. I usually install mine a little retarded for that reason but don't have water in exhaust problems as you do...

yes, advancing the cam would help...the flappers also work like a check valve of sorts to help as well..

You are correct - the numbers I listed from the card are at .050, so I guess the valve can actually be off its seat a lot sooner than that. I do know that this cam gets the valve open in a hurry. I don't have any numbers at .004 or .006.

Intake centerline is 110* ATDC, and exhaust CL is 118* BTDC. I'm far from an expert but I think that means the cam will be 4* advanced when installed "straight up". That's the way I did it - dot to dot, put a degree wheel, established true TDC with a pointer, and verified that the valve events with the wheel and a dial indicator. Also, the cam card says to install it "* *", which I would take to mean straight up.

Bob doesn't generally want to have the full specs for his cam posted on the web, and I can understand him wanting to protect his intellectual property. He has helped me out lot, so out of respect for him, I don't want to post the full specs out here on the WWW.