Help 1985 Scarab 454 engine trouble
 

Hey if anyone can give me some imput it would be helpful. Heres the situation. I have a 1985 Scarab 3. with Twin 454 HO 370 HP. I had an over rev situation when one of my drives blew. I shut it down fast, Much money later with new drives i now have a new problem. My left engine is only runing on 3 cyclinders. People are telling all kind of things. Like i have bent valves, droped my valve seats, or even just blew my head gaskets. I lost 3 on one side and 2 on the other. It pops back threw the carb. When engine is cold i can get up to plain but when engine is warmed up no power when under load. Any ideas.

Also anyone know how i can find the specs for the engines on this boat ?

Re: Help 1985 Scarab 454 engine trouble
 

I doubt your engine is running on only 3 cylinders. I would start with a compression check first. Buy a compression tester, remove spark plugs, screw tester in, open throttle fully, crank engine over for about 4 seconds. Make a note of each cyl compression. Chances are if you over revved it you may have damaged valves, springs, etc.

Re: Help 1985 Scarab 454 engine trouble
 

compression test will give you an I dea of what is going on, if you want to know exactly, do a leak down test........or get them done

Re: Help 1985 Scarab 454 engine trouble
 

just to let you know, it was only runing on 3 cyclinders i took off 5 spark plug wires and kept them off as i was looing for the bad ones. only 3 off would change the RPM . I will do compression test i know which ones are bad , but i know the heads have to come off.