VelocityMike

My aunt has a 29 Scarab with twin Merc 350 Small Blocks. At the start of the season both engines were missing extremely bad so she took it in for repairs and they found two cylinders on each engine pooched because of water, both engines had 250 hrs on them. The reason for the water we were told was there were no flappers in the exhaust and so water was getting back in the exhaust thus into the engine. Two long blocks later she was boating again until they winterized the boat and found rust on the plugs again. Now her friend is saying cam overlap. Does anyone know if this is a problem on this motor? Any advice would be great.

berns29scarab

first occurance i've heard of...best of luck

berns29scarab

i would also post on the scarab forum

zoomba

I'd check the exhaust manifolds, and the water elbow/riser gasket flanges and gaskets. Did they replace all that stuff when they did the blocks?

You can definitely get water in the cylinders if the manifold riser gaskets are leaking.

Dave
22'Wellcraft Eclipse

tssteph

I do not have this problem with mine.

fund razor

Ok.... so first it's the flappers and now with two new long blocks it's Cam overlap? Doubt it.

I'm with Dave.... exhaust manifolds/gaskets.

Lots of small blocks fall victim to it.

In fact, I think that I'm gonna do exhaust manifolds in my 26 with SBCs in the spring just because. They're too old and I'm taking chances.

VelocityMike

Hey guys thanks for the advice. When they replaced the engines they also put new manifolds and risers on. Also by flappers I mean it has tip flaps but no internal flaps.

blue thunder

At one time I ran merc centerrise exhaust with the 3" spacers. No matter what I did I couldn't keep gaskets from failing in the riser setup. New parts didn't matter. There was way too much weight put on the long threaded rod riser bolts to keep the exhaust from moving when running hard.

BT

Strip Poker 388

iTrader: (6)

I think on the 29 scarab exhaust tail pipes are high enough not to get water from that way.The cam would have to be not stock for reversion i would think .

I bet it was the exhaust that is and was the problem. I have seen it on 2 scarabs. here is a link to a thread I did on a Buddy's. his was the worse I have ever seen fresh water boat also
http://www.offshoreonly.com/forums/s...highlight=rust

The other scarab was salt water and it was leaking from the cracks and rusted out manifolds.he did not even know it.

I also did a Buddy's Sea Ray 454 1996 exhaust also. One side was good and the other was leaking on the inside . the boat was in perfect condition and no signs of rust on the out side of the exhaust. he always flushed it after trips to the coast, he was real anal about it.

also it could of froze and cracked ?

Blown head gasket?

good Luck

Rob

redfountain420s

I also own a 30ft scarab with twin small blocks and had the same problem with mine when i bought it and it was the exhaust that was the problem. I had the manifolds and risors resurfaced and that solved the problem. But my boat has gil high tourqe exhaust not stock