WOT Problems HELP PLEASE!

J

jaysnewboat

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Joined
Jun 26, 2010
Messages
4
I am having a problem with my mercruiser inboard 4 cylinder when I throttle up with no load(neutral) the engine revs fine. As soon as I put a load on it I throttle up and it revs up for like 45 seconds and then the engine bogs right down?? I can run at low throttle engine runs fine but as soon as I WOT the engine bogs right down. I have changed all the regular items points, condenser, coil, plugs, wires fuel filters etc. Even replaced the Carb with a factory rebuilt. Still having this problem. Can someone please give me some information on how to do a complete timing alignment. I have a feeling that the all the components are not set to top dead center because when I was adjusting the timing way out of scope seemed to make it run better.

Thank you in advance.

No pun intended.
 
J

jaysnewboat

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Jun 26, 2010
Messages
4
Re: WOT Problems HELP PLEASE!

I should add that I bought this boat and was not the only one working on the engine prior owner worked on it as well. That is the reason for me hinking timing may be way off.
 
J

jaysnewboat

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Jun 26, 2010
Messages
4
Re: WOT Problems HELP PLEASE!

I have downloaded the manual thank you for the link. I have checked everything that it says to check in the manual and things look good as far as the timing is concerned. could it be the fuel pump?? I am going to get a rig to test pressure and vacuum as well as look for air in the lines. I checked the vent to the fuel tank air is going through the vent fine. The engine is a 1984 four cylinder mercruiser 488. It has a mercruiser outdrive. When I start off it actually goes ggod for 45 seconds then dies back to a bog let off the throttle and it catches up and I can run at lower throttle like a 1/4 to less than half and it runs fine but when I trottle up bogs down??
Seems to be either fuel starved or over fueled I am not that familiar with this type of thing so I would appreciate some opinions.
Thanks Jay
 
Bifflefan

Bifflefan

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May 27, 2009
Messages
2,933
Re: WOT Problems HELP PLEASE!

jaysnewboat said:
I have changed all the regular items points, condenser, coil, plugs, wires fuel filters etc. Even replaced the Carb with a factory rebuilt. Still having this problem.
Click to expand...

Not one of those was the fuel pump.
Id say it is shot. Pumping only enough gas to make her idle. You have replaced everything else, whats it gonna hurt.

The pump is 175.00 at Napa. Or about the same price in the store here. I just replaced mine last week, I had the same issues as you are having.
 
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