Honda-10 Outboard trouble

[smithrandall]

Went out to the boat this weekend and started up my old 1988 Honda 10 h.p. but everytime I rolled the throttle from the start position to the idle position the engine would shut down. It would continue to run if I kept it at a high setting.

Everything seemed to be fine when I took the cover off. I made sure the sparkplug was seated properly. Fuel line seemed fined.

The only thing different from last time I ran the motor was I apparently didn't tilt the engine out of the water. It could have been messed with by someone else but I probably forget to raise it after I locked it. But that shouldn't have done anything.

Any ideas?

ModsEdit: Just to clarify title ~fc

[James V]

check for bad fuel or stuff in it and filter. Check Idle adjustment screw.

[Don T]

Hello,
What James said, since we don't know how long it's been since the last time the motor ran I'll take a guess. If fuel sits in the carbs a long time it can gum up the pilot (idle) jet. Tilting the motor up probably stops this from happening because the pilot jet is no longer down in the fuel when it evaporates. Also, water can collect in the bottom of the float bowl. The pilot jet is the lowest point so a small amount of water will stop it from idling but the main jet is clear. Try draining the float bowls, collecting what comes out to see if there is water.

[smithrandall]

I will check that. Thanks.

[puggsy]

If it is a two stroke then it is always best to remove the fuel line and keep the motor running until it actually runs out of fuel. This way all the fuel [ petrol / oil mix ] gets used up and no oil residue is left in the carby bowl, or the jets, and all is left clean for your next startup. Puggsy

[beene]

My 7.5 Honda '88 was doing that also.

Took it to the shop, they took a wire with some varsol and cleaned up the choke/carb/trtl body areas.... runs like a top again.

G

[ronacarme]

Idle jet gummed closed? Ethanol in the gas? How long ago since the last use of the motor? Did you previously fill your tank with ethanol free gas?

The following summarizes what I have read, following my own experience in several strandings over 3 years by a prior 4 str 9.9 motor fueled by E10 gasoline, namely....

Ethanol laced gas has a relatively (compared to gasoline without ethanol) short storage life in the station tank, shorter in your boat tank and fuel lines, shorter yet in your carb (maybe only 2 weeks in hot muggy weather) .....and as it ages it may
1.phase separate..... to leave atmospheric condensate water at your boat tank fuel uptake and lower octane rating of remaining gasoline and/or
2. form gummy deposits in your carb jets and float valve seat.
Also, Stabil can extend the useful life of ethanol laced gas but only for a limited time (e.g. probably not for an 8 month winter layup).
Also,ethanol in gasoline is a great solvent and may dissolve gum left in existing fuel lines by prior ethanol free gas and so even more rapidly gum closed your carb jets and valve seats.
Also, at least one state (MI) posts no ethanol content warning on gas station pumps, if content is not more than 10%.
Thus, in carb gumming situations nowadays, I tend to think first of old E10 fuel as the culprit.
Good luck.....Ron

[smithrandall]

It had been two weeks between last running the motor and this event. I was unable to go up this weekend and try anything.