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Old 08-06-2006, 08:26 PM   #1
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Help 454 HO 370 hp Scarab

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 ?
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Old 08-06-2006, 08:54 PM   #2
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Re: Help 454 HO 370 hp Scarab

I would do a compression test before I did anything else. That will at least give you a idea what the problem is. It could be something stupid like a loose rocker arm- but a compression test will give you a place to start. I think I might have the specs at home on those engines- I will check.

Good luck-

Scott
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Old 08-06-2006, 10:56 PM   #3
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Re: Help 454 HO 370 hp Scarab

Second the leak down test.... I hate to ask... but have you checked your distrbutor? Sounds like timming is way off... maybe rotor is out of place and you are missing.
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Old 08-07-2006, 11:31 AM   #4
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Re: Help 454 HO 370 hp Scarab

Could the timing chain have jumped a tooth?
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Old 08-07-2006, 01:39 PM   #5
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Re: Help 454 HO 370 hp Scarab

Sounds Like Bad Rings
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Old 08-07-2006, 06:04 PM   #6
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Re: Help 454 HO 370 hp Scarab

Thanks guys for your imput. I have found the problem i took the heads off and i have sunken seats and broken valves. Heads are trash. Now i need new or some used heads
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