4.3 mercruiser loses power @WOT

[63 Nova]

I have an '89 Sea Ray w/ 4.3 mercruiser/Alpha 1 just bought from co worker. Here's the problem: Cranks and idles fine, takes WOT fine until you back off to less than WOT. Then if you try to give it WOT it acts like it wants to bog, slows down like it is losing power but does not cut off. The last time at the lake I heard what sounded like back fire through the carb a couple of times while trying WOT. Any help would be wonderful, I'd like to have some back ground before I take it for repairs.

 

[Bondo]

Re: 4.3 mercruiser loses power @WOT

Sounds like it's Going Lean.........<br />Change the Fuel Filters...............<br /><br />If you're Lucky,<br />It won't be any Deeper than That............

 

[Westdevil]

Re: 4.3 mercruiser loses power @WOT

check points/plugs/condensor/rotor

 

[Tufan]

Re: 4.3 mercruiser loses power @WOT

I'd also check the fuel - water seperator.<br /><br />Good luck

 

[Blk-n-Blu]

Re: 4.3 mercruiser loses power @WOT

63, Also check to make sure the choke is fully open when the engine is warmed up!

 

[63 Nova]

Re: 4.3 mercruiser loses power @WOT

Thanks guys I changed the fuel seperator, Plugs were changed when I bought it. We took it out today and that didn't help, however we think it is a fuel starvation problem. I ordered a carb rebuild kit today, it cross referenced to an automotive rebiuld kit sposed to be the same thing . Any other suggestions?

 

[jesseoshea]

Re: 4.3 mercruiser loses power @WOT

I agree on checking the other tune up parts (cap, rotor, plugs, wires). I have had a similar problem twice on my boat. First time it was the carb. Second time it was the coil going out. If it's the coil it will progressively get worse. Sometimes you can hear the coil arcing if you're lucky. I though it was the carb until I ran the boat at night and saw it arcing. Also the chip like piece in the distributor under the cap and button is notorious for failing, especially if it hasn't been replaced by the new style (which is black instead of looking like a small circuit board).

Goodluck!