93 Merc 175 carb / fuel issues

[SunBum]

*(@&$)*&@$)(&%


Daggumit! I just typed up a full, detailed and comprehensive explanation of my problem and when i went to submit it to post, something happened and I lost it!



So here's the new, briefer version. Any help you can offer is most appreciated.

1993 Mercury 175 outboard.

Full tank (70 gallons) of 9 - 12 month old fuel, not sure if stabilizer was added (I doubt it)

Boat has only been in the water once in the last 12+ months.

Cranked it on the hose a couple of month ago and it cranked with relatively little fuss. Seemed to run pretty well after having sat for so long.

Put it in the water briefly a few weeks ago and got it to crank and it ran OK, maybe a little sluggish, but nothing terrible. Only ran it for about 15 or 20 minutes.

Last week, put a can of Seafoam in the tank and put it back in the water.

Now, revs / runs OK in neutral, but no power at all in gear and only about 1900 RPM at full throttle.

Sound like clogged carbs?

Is this a do-it-yourself project for those (me) that are mechanically inclined?

Any way to 'clean' them without dismantling them?

Is the tank of fuel OK to use?

Thanks for the help and sorry for the lack of detail.

 

[j_martin]

Re: 93 Merc 175 carb / fuel issues

*(@&$)*&@$)(&%


Daggumit! I just typed up a full, detailed and comprehensive explanation of my problem and when i went to submit it to post, something happened and I lost it!



So here's the new, briefer version. Any help you can offer is most appreciated.

1993 Mercury 175 outboard.

Full tank (70 gallons) of 9 - 12 month old fuel, not sure if stabilizer was added (I doubt it)

Boat has only been in the water once in the last 12+ months.

Cranked it on the hose a couple of month ago and it cranked with relatively little fuss. Seemed to run pretty well after having sat for so long.

Put it in the water briefly a few weeks ago and got it to crank and it ran OK, maybe a little sluggish, but nothing terrible. Only ran it for about 15 or 20 minutes.

Last week, put a can of Seafoam in the tank and put it back in the water.

Now, revs / runs OK in neutral, but no power at all in gear and only about 1900 RPM at full throttle.

Sound like clogged carbs?

Is this a do-it-yourself project for those (me) that are mechanically inclined?

Any way to 'clean' them without dismantling them?

Is the tank of fuel OK to use?

Thanks for the help and sorry for the lack of detail.

When this engine is starved for fuel, it often is hurt very severely, as cylinder temperatures go off the top of the scale.

SeaFoam (mostly alcohol) in an old tank of fuel (likely with a little water) would probably settle out into an unburnable mess at the bottom.

To answer your questions.
1. YES
2. NO
3. NO

Pickup screen and fuel filter likely clogged as well.

hope it helps
John

 

[SunBum]

Re: 93 Merc 175 carb / fuel issues

Hey John, thanks for the reply.

Are you saying 'YES' it sounds like clogged carbs or 'YES' it's a do-it-yourself-type project?

And I know that do-it-yourself means a bunch of different things to different people. I can do just about anything mechanically as long as special tools or special knowledge aren't required. I really think it shouldn't a problem except if carb adjustments (dialing it in type stuff) are required.

Also, the carbs were cleaned / rebuilt a couple of years ago (this happened before) and the guy used some kind of ultra-sonic vat to clean them. Is that necessary?

Thanks again.

 

[j_martin]

Re: 93 Merc 175 carb / fuel issues

Yes and Yes.

Unless they're really caked up, spray can carb cleaner should get the job done. They're really pretty simple, and likely you'll only need the gasket kit, no needles or jets.

Ordinary hand tools are all that's needed. They're fussy on float level and even torque on the bowl screws.

Motor fuel is made by cracking long chain hydrocarbons into shorter chains. They want to recombine somewhat, and so if you let it sit around, it'll form long chains that manifest as varnishes and such. Alcohol and condensation add to the problem. If you then add a "cleansing" additive to the tank, it just stirs it all up.

If it were mine, I'd pull the fuel out of the tank, run it through a 10 micron bag filter (except any obvious separation product at the bottom) and burn it in the family bus or work pickup. 2 cycle oil in it won't hurt a thing.

hope it helps
john