motor issues

[Lake Alice]

I have an evinrude 6 horse, 1989, that isn't running well. It will not run at full tilt in gear-won't go to the very top speed, just bogs a little and stays short of it. If you pull the choke it runs at top speed for a few seconds, then backs off. It also tends to kill as you idle it down to slow speed, and then it's difficult to re-start.

New plugs, fresh gas (although I may have overdone the sea foam a little--could that do it?) clean fuel filter.

any ideas?

[eyebjim]

It sounds like the carb high speed jet is plugged. It can get gummed up from bad gas/ethanol and get plugged or restricted. This will lean the motor out and cause it to run slow or die altogether. This is not good for the motor. If you have a high and low speed adjustment screw you may just be able to screw the high speed screw in all the way and then back it out to where it was. This does not clean it out but will often make it run. The real fix is to take apart the carb and clean it. If it has a high speed screw you can remove it and spray carb cleaner into the hole and clean it with a q-tip and clean the tip of the screw.

[Lake Alice]

Thanks. I will try that. I assume if it does not have a screw I have no other option than taking the carb apart and cleaning it? Or is there anything else I can try?

I just bought this motor, so it wasn't my bad gas

[boatfixer]

You only have a low speed adjustment on that engine. The best thing to do is to rebuild the carb with a new kit. You can dump a can of sea foam in it and try that also, but a good cleaning is the best thing to do.

[Minnesota Fats]

Don't use any seafoam unless you intend to run the entire tank of gas through quickly (ideally same day) AND never use more than the recommended ratio. Letting seafoam sit in your fuel lines and fittings can dissolve them/dislodge varnish and gunk and can actually make problems worse. Pull the carb out and clean it the old fashioned, and make sure your needle and seat are clean in addition to your main jet.

Seafoam causes more problems than it solves because people use it wrong.

[BobT]

I think that is the first time I ever heard about that? My guess is that if you use it regularly it won't be a problem but to use it in an old system after years later may create issues. This would be similar to the issues when ethanol was first introduced. The ethanol caused similar issues in old fuel systems.

Bob

[Minnesota Fats]

The problem can definitely be worse in old systems that have a lot of buildup, but the fundamental problem with it, like ethanol, is that it is a strong solvent that attacks rubber and plastics. If it is used quickly, it doesn't have time to do much damage, but if it sits long enough, it can damage even new stuff. My 4 wheeler had 150 miles on it and some seafoam dissolved the plastic from the gas tank enough to coat the inside of my float bowl green (the color of the gas tank) plus plug up my main and pilot and completely stick the needle to the seat. Using seafoam chronically as a fuel conditioner/preserver is probably not the best idea - Stabil or OMC 2+2 works much better and they are safe on plastics and rubber.

[boatfixer]

AND never use more than the recommended ratio.

You're right, I should have worded it that way. Thanks for correcting that one.

[Surface Tension]

Your probably looking at a carb cleaning and kit.

Before you do that check the hose connections from the tank and all fitting. Check the screen on the fuel pump. How is the bulb when this happens? Can you pump it up and does it run OK for a short time or is it tight?

[Basseyes]

Use sea foam all the time and have never had problem one with it. Do agree it can cause problems if stuff isn't taken apart and cleaned properly. I have a fair amount of small engine equipment of all kinds, variteys and ages. Since I've gone to useing all non oxy fuel in everything and useing seafoam have had very little problems at all with anything. With that said it can't cure serious problems but if used properly with preventive maintenance it can help prevent some.

Have a 6 hp johnson that was doing the same thing after I first got it. New carb kit and fuel pump now runs fine. Not all that hard of a fix and half way cheap if you can do it yourself. Takes some patients and attention to detail.

[Lake Alice]

Thanks for the advice everyone. I pulled out the one screw I could see on the carb--it had a little spring around it-- sprayed in carb cleaner, screwed it back in, pumped in new gas with no sea foam at all, and she fired right up and ran like a top. Idled down without killing, ran great at top speed, excellent.

Then the hard plastic outside on the fuel pump cracked and gas spewed everywhere. I dabbed some epoxy on it and let it sit overnight.

Next day, it fired right up and ran like a top again for a half an hour, up and down the shore, all speeds, and then died. I could not restart it. It was having trouble getting gas to the choke and then into the carb. A little would get in, then it would start, then die.

I assume I need a fuel pump.

[marine_man]

yep... sounds like you need a fuel pump.

If you prime the primer do you get gas to the carbs then?

marine_man

[Lake Alice]

A little, and it's inconsistent. I'll do the fuel pump and see if that does it.

FYI everyone I am also in the market for a used short shaft, pull start 18-25 horse outboard.

[sikasoman]

Had very similar symptoms as you describe with my 1977 9.9hp Johnson. After carb cleaning/rebuild,replace the spark plug, etc....it turned out to be a bad gas line between the tank and the motor!!!! I replaced the hose/primer bulb assy and the motor runs like a sewing machine!!!

[eurolarva]

When you get that new fuel pump you are going to want to adjust that screw in the carb you removed. If it was discussed eariler in this thread on how to do it forgive me. That screw controls the amount of fuel to air ratio that is burning mostly at idle and should be set to run slightly rich versus slightly lean. Best way to adjust is when motor is running well put it in forward gear and idle down as low as motor will go and still run. Make 1/8 turns clockwise every 20 seconds on that screw till it starts to rev or race. Go back the other way and repeat slow turns till it starts to bog down. Go exactly between these two point then turn the screw about an 1/8 turn counterclockwise.

[Lake Alice]

Thanks again guys. Great advice.