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OMC 2.3L running like a cammed out Chevy

N

nathanjaybar

New member
Hi all. I am a new boat owner (1988 Reinell 170M w/ OMC 2.3L I/O) and first time poster to this forum. This site has been a wealth of information, so to everyone here, thank you already.

I've been working on the boat for the past few weeks, and finally got it running. It had been sitting for a couple years from the previous owners so I figured I'd go ahead and do a full tune-up for good measure. I've done the following:

- Plugs + wires
- Distributor cap and rotor
- Coil
- Points, condensor
- Oil change
- Battery
- Rebuild and clean mechanical fuel pump
- Rebuild and clean carburetor
- Drain fuel tank + new gas

Right now, I'm experiencing 2 issues:

1) Engine will not start unless I disengage the gears and pin it full throttle, with a little bit of pumping of the throttle.
2) Once started I can not pull back on the throttle too much (have to stay at 50-75% throttle) or the engine dies. When it's running it sounds like a cammed out Chevy with a very aggressive throaty rumble - like it's going to die on every stroke. Normally giving it some gas will keep it from cutting out, and is spitting some pretty thick white smoke.

I have not checked timing yet, I need to get a timing light. I've adjusted the idle screws to just under 2 full turns out, I have not touched the idle stop screw from its previous position of the last owner. I have not run the motor longer than a few seconds, I can put the earmuffs on this weekend and see if things smooth out as it gets warmer.

Any advice is welcome and appreciated!
 
1) Engine will not start unless I disengage the gears and pin it full throttle, with a little bit of pumping of the throttle.
2) Once started I can not pull back on the throttle too much (have to stay at 50-75% throttle) or the engine dies. When it's running it sounds like a cammed out Chevy with a very aggressive throaty rumble - like it's going to die on every stroke. Normally giving it some gas will keep it from cutting out, and is spitting some pretty thick white smoke.
Click to expand...

Ayuh,..... Welcome Aboard,..... Sounds like yer carb rebuild was a total Failure,....

I'd do a compression test,.... while yer at it, look for signs of water in the cylinders,.....
 
bondo said:
Ayuh,..... Welcome Aboard,..... Sounds like yer carb rebuild was a total Failure,....

I'd do a compression test,.... while yer at it, look for signs of water in the cylinders,.....
Click to expand...

Thanks, happy to be here.

I figured the carb was more than likely the culprit, but is there anything in particular I should be looking out for? I replaced all the gaskets, accelerator pump, set float levels according to the build sheet, cleaned out all passageways and lubed all exterior linkages. The only thing I did not do was replace the check balls.

I was planning to do a compression test just to see where I'm at with it, hopefully tomorrow. I'll post the results here when I have them.

EDIT: Also, boat hasn't seen water for years so I don't think water in the cylinders is possible.
 
EDIT: Also, boat hasn't seen water for years so I don't think water in the cylinders is possible.
Click to expand...

Ayuh,..... Yer supplin' water to the motor when ya try to start it,.... Right,..??
 
bondo said:
Ayuh,..... Yer supplin' water to the motor when ya try to start it,.... Right,..??
Click to expand...

The boat is on a trailer in my garage, so not just yet.

I pulled the carb off again, replaced the check balls, cleaned out the passages and re-measured the float levels. Threw the carb back on and it fired up almost immediately. It died right away, then started back up with a little bit of throttle. It was struggling a little bit, but I almost got it to idle on its own. I think whatever was going on I unknowingly fixed. Next is a proper carb adjustment. Before I put it in water though, I'm going to replace the thermostat and gaskets. I'm pretty sure they're original to 1988.
 
Ayuh,.... If yer runnin' the motor, with no water runnin' through it, you burnt up the impeller, 'n the rubber parts in the exhaust by now,......

Most of Us use muffs on the outdrive, fed by a garden hose,.....
 
bondo said:
Ayuh,.... If yer runnin' the motor, with no water runnin' through it, you burnt up the impeller, 'n the rubber parts in the exhaust by now,......

Most of Us use muffs on the outdrive, fed by a garden hose,.....
Click to expand...

Yep, have the muffs. The engine hasn't been run for more than 10 seconds or so, and has not reached operating temp in the time I've owned it. The entire impeller assembly is being replaced, I'm not sure how old it is so I'm doing that for good measure.
 
The engine hasn't been run for more than 10 seconds or so,
Click to expand...

Ayuh,.... That's the Point,.... 10 seconds is to long, without water to the pump, with the muffs,.....

I don't even crank a motor over on the starter, til I muff the drive,.....
 
bondo said:
Ayuh,.... That's the Point,.... 10 seconds is to long, without water to the pump, with the muffs,.....

I don't even crank a motor over on the starter, til I muff the drive,.....
Click to expand...

Good to know. When I get the new impeller on I'll be sure to muff it every time I start it.
 
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