1992 mc 4.3l

Boilers2000

Petty Officer 1st Class
Joined
Jun 15, 2018
Messages
252
Just bought boat with a 1992 MC 4.3L. Compression tested all cylinders, range from 150 to 160 psi. Seatrailed next, but fired up on first turn of the key, accelerated nicely....Fast fed to today...engine fired up at launch no issues, docked and once all gear was loaded fired up again, cruised through wake zone no issue, accelerated to 4000 RPMS back down to 3500 to cruise and cruised for 10 mins. Idled for a bit to get the tube hooked up. Engine died, struggled to restart and finally did. Slot started to tighten the rope, started to accelerate and engine died again. Got engine restarted 3 or 4 more times only to have it die when trying to accelerate over a 2200 RPMish. Once I managed to get docked, fired up engine in natural and tried to rev engine, but anything north of 2200 rpms start go sputter and die. Throttle only button is also really sticky. Any suggestions? My guesses until I can get a set of muffs is not enough fuel from secondary on the carburetor or failing fuel pump? Any other ideas...what order would you troubleshoot. Thanks in advance!
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
7,343
Would suspect your not getting fuel. Take off the fuel filter and dump the contents look for any thing but clean gas. If it's all clogged up then likely cleaning out fuel system and carb is in order.

Check the fuel pump either by putting in a test gauge in fuel line or disconnect the fuel line and turn engine while collecting fuel in a small container
 

Rick Stephens

Admiral
Joined
Aug 13, 2013
Messages
6,118
I'd agree with Scott, time to go through the fuel system. I would get a kit and go through the carb, check the screen under the fuel line inlet fitting. If there is a canister filter, check it as Scott suggested. If not, consider adding one. Double check the timing. Make sure it is properly advancing.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Sounds like it's getting worse. How old is your fuel?

About the only other thing that will do that to those engines is old spark plugs. ... When were they last changed? (With my previous engine, I could only get 200 hours out of a set before the engine started acting up. )

Chris. ....
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
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52,155
Just bought boat with a 1992 MC 4.3L.

with any new to you boat, you should do all the maintenance. impeller, bellows, inspect u-joints and gimble bearing, gear lube, engine oil and filters, plugs/wires/cap/rotor.

in addition to above, it sounds like you have fuel system issues. pull the filter, empty its contents in a clear bag. if you see a separation, you have water in your fuel. replace the filter

you may need to clean your carb. also check your anti-siphon valve
 

Boilers2000

Petty Officer 1st Class
Joined
Jun 15, 2018
Messages
252
Thanks for all the guidance. Will start going through these all starting tonight. Fingers crossed it's an easy fix.
 
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