Need help with merc 3.0

[fuze]

i have an 1985 merc 3.0, that surges at 4,000 rpms, and when i turn hard to the right. it runs fine when turning left, at idle and lower rpms. does anyone know what the problem is and how to fix it. thanks

 

[fuze]

Re: Need help with merc 3.0

thanks for all of the replys and suggestions.

 

[marlboro180]

Re: Need help with merc 3.0

Is your trim all the way down when this happens? Don't know the hull shape but my 4 winns does this if its trimmed up while cranking hard turns or running hard near WOT- the prop comes out a bit and sucks air down instead of water---

"Surface cavitation"

Is it just a surge or does the motor really wind up freely? If really winding up near 4300 rpm , be careful it doesn't go beyond that!

What prop you running?

 

[Bondo]

Re: Need help with merc 3.0

i have an 1985 merc 3.0, that surges at 4,000 rpms,
thanks for all of the replys and suggestions.

Ayuh,... How about a little Service History....

As far as the Lack of Replies,... It probably has to do with the Lack of Info...

 

[fuze]

Re: Need help with merc 3.0

the trim is about half way up when running wot. it doesnt spin out. it loses power so rpms drop off.

 

[marlboro180]

Re: Need help with merc 3.0

Gotta agree w/ Bond-o- more info would be helpful. Guess I was hoping for something simple w/ prop issue but now it is clear it is not a surge but loss of rpm's / power.

How's your fuel system? ( float level?)

 

[searay3]

Re: Need help with merc 3.0

A 3.0 is not a horsepower package. Need to know how big a boat, what kind of load, what are you using it for. If you have a 21ft boat, pulling a skier, with people and gear onboard, going into a turn WILL slow it down considerably. I think you get what the guys are saying about more info....

 

[Bondo]

Re: Need help with merc 3.0

and when i turn hard to the right. it runs fine when turning left, at idle and lower rpms. does anyone know what the problem is and how to fix it.

Ayuh,... There's a restriction in the fuel pickup,+ when the fuel sloshs around on a Port turn,....
It runs outa Gas.....
At less than hammering it, it isn't needing near as much fuel, hence it runs fine....

When was the last time this rig saw a Full,+ Complete Tune Up,+ Service,..??