Went to the river this weeken me and a buddy my boat ran great his boat possible some serious motor problems so shorten up the story when on a long 20 plus mile run dwn river on our way up river he decided to flat foot it almost all the way back at 4500 rpm when we parked it motor was pretty hot oil pressure went from 65 dwn to 20.  We let the boat sit drove it to the launch ramp running badly    Later that nite pulled the plugs water in 6 of 8 cylinders milk shake oil  I think over heated the oil block seemed warm valve  covers un touchable is it possible to blow both head gaskets at once.  He did a compression test today and to dead cylinders  motor is 100% stock 454  any insite on this would help thanks


Sent from my iPad using SoCal Jet Boats

Time for a new motor

So why do you suppose it had a detination problem in one cylinder would the crack in the head do it


Sent from my iPad using SoCal Jet Boats

Sounds like the motors coming out going into the shop what should I be looking for so this doesn't happen again it has center rise exhaust and 750 single pump vac sec and a msd ingnition


Sent from my iPad using SoCal Jet Boats

That think detonated itself to death. I agree with Mr. Joe. Lean as hell and probably too much timing.

What carburetor is on this deal, 750 vacuum secondary what?

Ir almost looks as though the vales started coming apart.

Fat is not fast, but it's safe.

Here's the other head


Sent from my iPad using SoCal Jet Boats

the carb was a vac sec carb that they made mechanical sec with a nut and bolt.

That modification killed that engine IMHO.

GT

That modification killed that engine IMHO.

GT

that sucks I called a carb shop asking if the carb would still wrk the same and he said if it's running good run it. I question that as soon as he bought the boat


Sent from my iPad using SoCal Jet Boats

If you are going to run that far and hard I recommend a step  retard box and set it to at least 3-4 degrees retard. You don't need all the that timing at full speed.