mercruiser experts

[frankgrimes]

Hi Guys,

My old man has purchased a Bayliner 3555 Avanti with "brand new" 2 x mercruiser 5.7l – not my ideal choice in a boat, but anyways!
Engines supposedly imported from usa with "racing cams" (The previous owner was a bit of a petrol head Im told )....issue is that both engines will stall below 1000rpm (Above 1000 they perform without problem) - With air cleaners off when turning over they are getting fuel vapours (So appears to be flooding)..mechanic checked one of the engines and found hydraulic lifters broken – replaced these but did not fix prob.
Both engines are exhibiting the same problems(i.e. less than 1000rpm they both stall), so the only unknown at this stage is the cams -
For the experts out there(As the old man is getting the run around, and he is 2 states away) - can/would cams present this type of behaviour?
Cheers,
Mick
NB - I have been told that carbs are stock, and they have been checked.

[Salad Fingers]

Im not expert on MerCruisers but big cams and stock carby on a small block chev is not a good look. Probably wouldn't cause the stalling, but anything is possible - really does depend on what the cam is though.

Are you talking about going to full throttle from under 1000rpm and then it stalls?
Or just will not idle below 1000rpm? If it wont idle below 1000rpm with no load then something is wrong, even a very large cam will let you idle below that.

I assume the timing/dissy(cap, rotor, etc) has been checked?

If you take the plugs out are they clean?

[frankgrimes]

Im not expert on MerCruisers but big cams and stock carby on a small block chev is not a good look. Probably wouldn't cause the stalling, but anything is possible - really does depend on what the cam is though.

Are you talking about going to full throttle from under 1000rpm and then it stalls?
Or just will not idle below 1000rpm? If it wont idle below 1000rpm with no load then something is wrong, even a very large cam will let you idle below that.

I assume the timing/dissy(cap, rotor, etc) has been checked?

If you take the plugs out are they clean?

Cheers mate.

Cams are unknown at this stage - Im told it is a mission to find out what they are?

Both engines will not idle below 1000(No load) - I'm hoping what you have suggested has been checked, but the boat/motors are in vic, and my old man is very vague on details!(He has told me 2 seperate "mechanics" have checked engines(Not cams though))

Mick

[krazyfisher]

did it idle under 1000rpm when he bought it? if yes than what has changed if no than why did he buy it?

[frankgrimes]

did it idle under 1000rpm when he bought it? if yes than what has changed if no than why did he buy it?

No - never idled under 1000, he "bought" it as a contra-deal...I told him he was crazy.

[Homer_Jay]

Hey Grimey, (as he likes to be known)


Not sure where he is but there is a guy in Victoria, Nick from Bayside Mairine. He is a bit of a guru with Mercruisers and helped me out alot when I had mine.

He used to be on this forum under the member name "BM" not sure if he is still around here.

PM me if you want his email. Im sure he will be more than willing to pass on some advice.

Cheers

[frankgrimes]

Hey Grimey, (as he likes to be known)


Not sure where he is but there is a guy in Victoria, Nick from Bayside Mairine. He is a bit of a guru with Mercruisers and helped me out alot when I had mine.

He used to be on this forum under the member name "BM" not sure if he is still around here.

PM me if you want his email. Im sure he will be more than willing to pass on some advice.

Cheers

PM sent mate - Cheers.