Diagnostic help needed: Calling all gearheads.

[rgranger]

Hello All

Took my new-2-me Balboa 26 out for her first shakedown cruise Sunday. As expected, a lot of things went wrong but most of those I know how to handle.

I had a lot of trouble with my 15 hp 4-stroke Honda outboard. It had been recently serviced by someone I trust and was reported to be "running great". But yesterday I could not keep it running unless I left the choke at half. And then it would stall anytime I tried to run it at low rpm. Since approaches to the dock under full throttle are frowned upon, I need to fix this.

So here are some additional variables. The guy at the shop had used his own fuel tank. I had emptied and replaced the fuel in my (internal) fuel tank prior to heading out. I also added a can of seafoam.

At this point, my best guess is that the in-line fuel filter might be clogged up with ick. Or maybe there was some sludge in the bottom of the tank that got up into the fuel injectors. But I'm not a mechanic and don't feel very knowledgeable on outboards so... If you have some suggestions, I'm all ears.

Thanks,

r

 

[SycloneDriver]

I doubt that it fuel injected, you did say it has a choke.

The idle jet in the newer 4-stroke motors are very small and easly plugged. You need ot pull the carb off and take it apart. Then spray it out with carb cleaner and real compressed aie. Put it all back togather. It should be fine now. If your not comfortable doing this get a friend to help, but be involved with the process.

Good luck and add a fuel filter.

 

[Gunni]

Doesn't a 15hp Honda have carburetors? In any case, what you describe reads like a classic case of fuel contamination and clogged jets. Removing the fuel was likely not adequate. The tank should be removed and cleaned.

 

[Rick I]

Hondas that won't run without a bit of choke need to have the carbs cleaned.

 

[rgranger]

Alright.... thanks guys.... got something to work from. Looks like a carb job and tank cleaning in my future.

 

[kloudie1]

another thing to check for is an air leak. since the service guy said it was ok, then certainly check the fuel side for contaminatin you may have swept into the engine.. but also make sure that the boat-to-motor connector is not leaking air. One way to check is to squeeze the bulb when the engine is running and open the choke and keep squeezing. if the engine runs OK then you may have an air leak somewhere between the motor and the tank .. because it runs ok kinda with choke, I am thinking the fuel pump is ok.

 

[walt]

sounds similar to what my carberated 4 hp four stroke Tohatsu was doing.

Turned out to be the low speed idle jet plugged. The hole on the low speed idle jet is really tiny..

 

[mark_swart]

I'm 99 percent sure it's your idle jet/pilot jet (depends on how it is configured.) Might just be a tiny piece of trash that got in there when they were doing the work. The quickest check would be to just drain the fuel from the carb and see if that takes care of it. If not, you'll need to pull the bowl and clean or replace the jet.

 

[Bill Roosa]

check the gas tank cap vent also.

 

[Tom]

I have a 7.5 horse honda.
My quick fix (it works every time (so far)) turn the idle mix screw all the way in, be gentle, and count the turns. Then screw it all the way out, spray carb cleaner in the hole, just a little. Wait about 30 minutes and spray again. screw the needle back in, NOT TO TIGHT!!! and then back it out the same number of turns. I always pull the fuel line off of the motor and run the carb dry at the end of the day

tom
s/v GAIA