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89 mercruiser 7.4 454 v8 with bravo 1, bogging down

Combs4993

New member
I have recently purchased a 89 powerplay spectra 222 with a 7.4 mercruiser in it, originally it was overheating, but was able to solve that problem, now it is bogging down or sounds like its out of gas, with it in gear I can get up to 3k rpm but if I pin the throttle it breaks up and sounds like it wants to die out.
Now heres the weird thing it doesn't do the with it out over gear I can rev it to high heaven and it be fine

Also the batteries aren't charging due to a loose alternator belt I think since I took it off to pull the sea water pump, I might not have got it tight enough, I was wondering if this would also cause this problem any tips or insight as to why it won't rev past 3k while in but would be greatly appreciated as I am just getting into the boating world recently

Sorry for the long post
 
Could be the anti syphon valve has clogged after a few decades of use....you can check for excessive pressure drop in the suction line feeding the fuel pump or use a fuel pressure gauge on the pump's output to verify its a fuel issue....

It isn't weird and the engine has no load on it so it's Air/Fuel demands are significantly different.

could also be the ignition breaking down...a spark tester or a timing light helps checking that out..
 
Could be the anti syphon valve has clogged after a few decades of use....you can check for excessive pressure drop in the suction line feeding the fuel pump or use a fuel pressure gauge on the pump's output to verify its a fuel issue....

It isn't weird and the engine has no load on it so it's Air/Fuel demands are significantly different.

could also be the ignition breaking down...a spark tester or a timing light helps checking that out..

I'll have to look into the anti siphon valve didnt know about those but ill start there, its unfortunate the the closest body of water is a hour away from me but I do have the muffs for the outdrive

I have A new fuel filter and fuel pump, a new distributor cap and rotor, as well as new plugs and wires on the way already

im going to check the alternator to make sure the belt is tight as well because i put a new circulation pump on and may not have gotten the belt tight enough as its not charging the batteries like it was before i did any work to it

Thanks for the info
 
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