srpbaer ... I have noted on a few occasions that when talking to these customer service people at teagues and others, they often lack substance to their advice. Start to ask technical questions outside the norm and you will see. The advise you are getting here is right on the money. Good things come to those who wait.

Good luck,

Oh yeah, I have the internal flappers with the counter weight and have not had a single problem with inversion. That is what you called it in your original post and I thought that meant backwashing, not reversion. Made sense to me... that is scarey.

BT

14 years later........if any of you guys are still out there! I have CMI E-top headers on my boat. The water exits thru a pipe fitting on the top of the exhaust roughly 8 inches or so before the tail. If you look in my tail pipe tho there are 3 little holes drilled in...the water jacket I guess you may call it. Little water does exit there. My question is can I use external rubber flappers to prevent water from coming in during launch, coming off plane, and sitting still when there are waves? I'm always nervous water will get in the pipes and I'll turn the key and boom! Just dumped more money then I have in this motor so I want to keep it going. Also if I can use the rubber external flappers is there any problems they can cause like forcing the exhaust water back in? Thanks guys

I continue to run the external rubber flappers only and have zero issues with backwash. And I have taken big wakes on the transom while floating enjoying life. I don't believe they have any effect on reversion whatsoever.

BT

I ran wet lightening headers for years with just ext flappers also. No issues what so ever and that was with cams even on 110 lsa. Been at this for over 30 yrs now and the most I had was a milkshake with a cam on a 108 but that was back in the day when reversion wasn't discused much and 75 mph was fast.

So the rubber external flappers shouldn't melt even with dry exhaust?

Btw I still think 75 is fast!! I start getting scared in the mid 80s

75 IS fast in the wrong boat.
My Daytona at 75 is like riding in a CADDY on the highway.

Neither Internal or external won't fair well with dry exhaust. Shotguns simple solution. The only rubber I like to smell burning is whatever I can get the tires to burn on a good brake stand and the smoke passes the front of the vehicle - you know your on a good one. Lol.

If you don't like the rubber ones go stainless that's what I did and looKS way better [IMG][/IMG]