OMC 120 Power Loss

[simbey1982]

Have a 120 OMC "iron duke" straight 4 engine with a Mercruiser Sterndrive

Just pulled the boat out for the first run of the year. Wouldn't start and had no spark, so I change the points and condenser (points gapped to .019). After some fiddling I finally get it to start, albeit a little rough. Put her on the water and it runs fine for an hour or so. Pull a tube and run around the lake. Then without warning the engine starts to have a sudden power loss. Engine sounds like its "bogging" down.

What i mean is I will accelerate to speed, then the rpms suddenly drop off and I lose all power until the engine dies. Starts right back up, It will idle and do low speed fine but once I start to give some throttle it will go for a few seconds then drop off. If I am quick enough and pull the throttle back before the engine winds down then it stays running.

Then after dying about 10 times the engine would not restart until I unhooked the throttle linkage and manually dumped fuel into the carburetor while turning it over. Then it started back up again enough to limp it to the dock.

Thoughts?

Cory

 

[Bondo]

and manually dumped fuel into the carburetor while turning it over.

Ayuh,...... Welcome Aboard,.... My guess is, she's Starvin' for gas,....

Probably water, 'n crud in the tank pluggin' the fuel filters, 'n carb circuits,...

 

[southkogs]

Welcome ... You have an OMC engine and a Mercruiser drive? That sounds a little off. Got pictures?

 

[Scott Danforth]

welcome aboard

a few things come to mind.

did you set the dwell?
then did you adjust the timing?
also, did you grease the points, if not, you may need to go back and check the gap. that little actuation finger needs a dab of grease

since this is the first time out this year, and the year is almost over, how old is the fuel?

 

[simbey1982]

Well I could be wrong the mercruiser stern drive but i know the engine is an OMC and the stern drive looks like the pictures of a mercruiser.

Did not set the dwell, Did not adjust the timing, didnt grease the points (Where on the points do you grease it?)

My understanding is I need a dwell meter and a timing light to set the timing? Im guessing there are stickys on how to accomplish both?

Fuel was about 11 months old, added stabilizer before storing. It was about a 1/3 of a tank then i topped it off with new fuel before going out.

 

[Scott Danforth]

Well I could be wrong the mercruiser stern drive but i know the engine is an OMC and the stern drive looks like the pictures of a mercruiser.

Did not set the dwell, Did not adjust the timing, didnt grease the points (Where on the points do you grease it?)

My understanding is I need a dwell meter and a timing light to set the timing? Im guessing there are stickys on how to accomplish both?

Fuel was about 11 months old, added stabilizer before storing. It was about a 1/3 of a tank then i topped it off with new fuel before going out.

well, there are your problems.

dwell is most likely off, timing is most likely off, and your fuel went to crap from sitting. (11 months is way to long to let fuel sit)

 

[southkogs]

Post a photo of your drive up when you can Simbey.

 

[simbey1982]

Alright I have the dwell meter, timing light, and remote start being shipped to me. I will follow the procedures in the tune up sticky and report back. South cogs I will post a pic later tonight when I get home.

 

[simbey1982]

No Title

Here is the stern drive

 

[simbey1982]

As for the fuel, I filled up on top of the bad fuel... do i siphon the whole tank and open up the fuel pump and carburetor to clear it out? Or can I just clear the stuff in the engine?

 

[southkogs]

Outdrive is an electric shift OMC Stringer.

I'd start with the timing and dwell ... mess with the fuel if that doesn't fix it.

 

[simbey1982]

Thanks boys I will report back after my trip next weekend.

 

[simbey1982]

This has merged into more and bigger problems..Im starting a new thread since it is new issues

 

[Bondo]

This has merged into more and bigger problems..Im starting a new thread since it is new issues

Ayuh,.... Ya might oughta keep goin' in this thread,....

Yer info 'bout yer motor, 'n drive are all here,....