Friend has a 29 Scarab with twin small blocks. Two years ago the boat had a very bad miss and she took it to a local mechanic to find that both engines had sucked water into them and lost a couple cylinders on each engine.
The cause of the problems was found to be that the flappers had gotten blown out of the tips and sucked water back into the engine. Two engines later and flappers reaplaced problem solved. This all happened mid summer.
That winter it happened again but was caught in time to prevent any damamge.
This year she called to have the boat pulled out and the mechanic noticed the boat had a miss again. He did a leak down check and there were two bad cynliders again on the port engine. Luckly this time a head job fixed the problem but the cause was no flappers again!!
Art Lilly has the boat now and told me that he is going to replace the tips with a different style to take care of the problem.


Has anyone else with a 29 Scarab had this problem before?
What did it take to fix it.

Any help would be great.

Thanks!

Thats suck dude!! I have never had any issues with flappers or reversion problems. It will be intersting to see if anyone else has had this issue.

Coming from a boat mechanic, it sounds like she probably has cracks/corrosion in the exhaust manifolds or the gasket between the manifolds and risers is leaking. They need to be removed and pressure checked.

No problems here at all. This issue/problem has nothing to do with Scarabs. This can happen on any boat. I agree on the exhaust manifold comments above.

When the engines were put in there were new manifolds and risers put on....

Did someone change Cam’s? That could (would) cause it to suck water.

It's got new Merc engines in it.

That boat with twins, has very little drop from the manifold to tip.... alot of the 29's had the Teague switchable muffler tips on them, and they didn't seem to have the water problems.

Mine has a single so I can't comment.

Mine did not have switchable exhaust and still does not and I have never had a problem.