1985 omc i/o problems excelerating

[Ryan O]

I'm having problems wile on the water. motor bogs down and I have no power but will run full throttle on land. been over the timing and cleaned out the carb. runs like a champ out of the water but wile in water it won't go faster then 8 or 9 mph and can't get full throttle. if operated by hand (not in gear) I can get full throttle and runs smooth. any idea's?

 

[Ryan O]

by the way it is a 2.5 liter four cyl omc stern drive

 

[hogg]

Is it otherwise known as a Me cruiser 140 Hp? I have some parts left over from a boat I had that had Twin 140's. Bogging or not accelerating on the Briny Deep is normally fuel related. The older 140's had a rebuild-able fuel pump. A nice 2bbl Carb and a metal fuel line from the Pump up to the Carb. If the Distributor timing is too fast (advanced) it will run fine in the driveway, but not under a load. Also the Distributor points set too narrow/Wide will cause the same thing. Have you done any work on it that might contribute to the problem. A self-inflicted wound is not out of the question. If

 

[southkogs]

Hi Ryan, and welcome aboard.

So, you're not seriously crankin' that engine WOT on land are you? Yikes! You can burn stuff up that way.

How long have ya' had the boat? Is this something that it just started doing? How's your compression on the cylinders?

 

[Ryan O]

I've adjusted the points and set the timing. The carb has been cleaned out but not rebuilt. I switched out the old fuel pump and installed a in line electric fuel pump. I think maybe rebuilding the carb mite help?

 

[Ryan O]

I've had the boat three weeks and in the water twice. It is a 1985 renken bow rider. The compression seems good in all cylinders. When in the water I can put it in gear and move slowly (no wake zone) when I reach open water I can accelerate a little more but that's it. It acts like it wants to go but won't. I don't run it wot on land but i'll bring it to full throttle briefly. When at idle speed it's taching at 1,500 rpm will not idle at 800 like it should.

 

[southkogs]

Have you changed lube in your sterndrive? I'm wondering how the boat would idle with the stern drive removed. Have you tried that to see if you can get it to idle at 800?

 

[bruceb58]

How fast it runs in neutral means absolutely nothing.

What is the history of this engine to you? What does the compression look like? Have you changed all the fuel filters? Age of the fuel?

 

[southkogs]

How fast it runs in neutral means absolutely nothing.?

Yeah ... I'm wondering if something isn't going on in the stern drive to "gum up" the operation. I suppose more trying to eliminate the stern drive as a problem.

 

[Ryan O]

All new fuel filters and pump, fluids in stern drive look good they're black in color not milky like water got in. When put I. Gear the dive pushs the boat with minamum effort forward and reverse. Engine oil is new no trash or metal shavings. I'm sure the carb is not performing properly mite be accompanied by other issues but I'm not sure what.