15 hp Mercury 2 stroke won't run

[pwmullins]

I have pulled the carb and taken it apart. It looked clean, no gunk anywhere. Put it back on and tried to start it. I also dumped the old non ethanol gas mix and put in new.

It will only run as long as the primer is in the carb. Doesn't seem to be pulling gas consistently from the tank. Could be the fuel pump. Any other ideas.

[Cadence]

Originally Posted by pwmullins

I have pulled the carb and taken it apart. It looked clean, no gunk anywhere. Put it back on and tried to start it. I also dumped the old non ethanol gas mix and put in new.

It will only run as long as the primer is in the carb. Doesn't seem to be pulling gas consistently from the tank. Could be the fuel pump. Any other ideas.

I believe someone mentioned sucking air someplace on the fuel line?

[pwmullins]

Thanks for all the good ideas. I've ordered a carb rebuild kit and will install it within the next few days as soon as it comes in and I will let u know if it works.

[a64pilot]

If it will only run when you pump the bulb it's very likely fuel pump or sucking air as was mentioned.
Is that what you mean by the primer is in the carb?
If primer is in the carb means enriching circuit on, then most likely idle circuit jet is clogged
Gotta know what primer is in the carb means


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[pwmullins]

Thanks for all the good ideas re my 15 hp Mercury. I bought a rebuild kit from Mercury Direct, Marshall , TX and rebuilt the carb. That did the trick. I think the injector diaphram was worn out . It was replaced along with the main jet and it runs fine. The motor is a 2000 model , so I guess it was time I did this.

[Cadence]

Originally Posted by pwmullins

Thanks for all the good ideas re my 15 hp Mercury. I bought a rebuild kit from Mercury Direct, Marshall , TX and rebuilt the carb. That did the trick. I think the injector diaphram was worn out . It was replaced along with the main jet and it runs fine. The motor is a 2000 model , so I guess it was time I did this.

Thanks! It is great to see positive feed back.

[pwmullins]

Thanks for all the replies. I rebuilt the carb, replaced the impellar in the water pump and got new non ethanol gas. Motor runs fine now with one exception.

It backfires through the carb every 30 seconds or so at slow idle. I think it is caused by not having the main jet adjusted correctly. Has anyone experienced and do you know the correct adjustment or any remedy if that is not the problem?

[Philsboat]

Sounds like it is running lean.With the engine off,turn the idle adj. screw in till it seats lightly.Back it out 1 1/2 turns and try it there.Make a note of how many turns it took to seat so you can return it to where it was.
If it runs rough at 1 1/2 turns out turn it slowly in and out to see if it smooths out.

[donradcliffe]

Visited a friend in the mountains last weekend, and one of the projects was her backup genset. It would start and run for a minute and die. A 5 minute wait would repeat the process. It was last run 9 months ago, and had been sitting around full of 10% ethanol gas.

Step 1 was to pull the filter (clean) and open the fuel valve--good flow. Step 2 was to pull the drain screw on the carb bowl--it was full, but when it drained and I opened the fuel valve, it flowed about 2 drops a second. Step 3 was to pull the carb, take off the bowl, and check the float valve--all OK.
Step 4 was to pull the fuel line off the carb and blow through the passage to the float valve--blocked.
Step 5 was a shot of compressed air in the float valve, and a piece of gunk about the size of a grain of rice flew out of the passage--problem solved.
Step 6 was a lecture about non-ethanol gas or fuel stabilizer.

I hate ethanol fuel.

[pwmullins]

Thanks Philsboat for your info....from one Phil to another....I did what you said and the motor runs great . The only thing is that at slow idle it seems to shake a lot more now than before. Do you know of any way to adjust the carb so it will run smoothly at low idle without shaking?

[Philsboat]

Originally Posted by pwmullins

Thanks Philsboat for your info....from one Phil to another....I did what you said and the motor runs great . The only thing is that at slow idle it seems to shake a lot more now than before. Do you know of any way to adjust the carb so it will run smoothly at low idle without shaking?

Look for an idle speed screw.It should be on the throttle linkage stop.Turn it to increase low speed revs until the shake goes away.Some newer motors don't have this feature.