Outboard not running well - need advice!

[evetsmd]

This is not my 225 Yamaha 4stroke on my 2520XL but it is a 1 1/2 year old Yamaha 25HP 4 stroke electric start that I use on my 14' Carolina Skiff.

Went to use it for the first time this year.....new tank of 89 octane fuel....hit the start button and it wouldn't start.

There is no manual choke on this engine!!! Figured it had to be a fuel problem....after checking all of the fuel lines, making sure the bulb was solid and looking at a very clear bowl fuel filter that is on the engine, still no deal on getting it started.

OK I removed the cover, looked for the air intake to the carb, blocked off 90% of it with my fingers and hit the start button. Bingo it runs at idle....rough but it runs. As soon as I remove my fingers and let it get full air intake it just stalls.

Called the dealer, explained all this to him and he tells me I have clogged ports in the carb......not covered by warranty, a function of ethanol fuel and with 1 1/2 hrs of work, $150 plus parts they would get it back up and running again. Says he sees the problem weekly.

Anyway I'm thinking - buy some carb cleaner like STP or Gumout, double the dose in say a gallon of gas, put something over the breather that will let the engine run, hook up the muffs and water and then let the engine run for say 30 minutes or so and see if the problem goes away.

Any thoughts or ideas about my approach? Open to any advice or suggestions before having to take it to the dealer.

Thanks

 

[jeffnick]

I'd consider that approach, but I'd dose the gas with BRP Engine Tuner (like this) or your favorite brand.

And I'd fill the float bowl(s) with it too and let it set for a couple hours before starting the motor (if there's an easy way to do it). In the days of de-carbing we'd fill the fuel filter with straight Tuner - she'd smoke like crazy on the straight tuner until it was run thru the motor, but she will run on it.

There's really nothing that I know of that you can run thru a motor to clear the carb of varnish that's taken a set (save disassembly) but if it's just thick you might have some luck.

Oh, and the directions say "Not to be mixed with fuel" because it's not a good idea to let it be in contact with internal parts for extended periods.

 

[DaleH]

FWIW up here in the Northeast, we've added Racor fuel/water separators even to the small 6hp to 8hp launches we use 24/7 ... as otherwise we too were clogging up the motors with the CRAP from ethanol fuels.

Boater's World sells Racor-type (Sierra actually) f/w system for < $30, with 2 cartridges. LARGE can cartridge too , which should last a long time on a small HP motor.

 

[goinsfishin]

Good luck with your dosing, hope it works.
Unfortunately my experience has been that once carbs get to that stage it's rebuild time.
Fortunately this can be a DYI project and save a bunch of $$ on labor. Rebuild kits are relatively inexpensive.
The most important part is to very carefully note how linkage is attached and the EXACT setting on the fuel idle mixture screw(s) for reassembly.
Otherwise its just a matter of taking it apart, carefully cleaning with carb cleaner and compressed air and re-assembling with new gaskets and rings from the kit. Takes an hour or so.
I've been rebuilding carbs all my life on everthing from RC model boats to antique trucks, my motorcycles next on the list since its running like crap.
I figure that with ethanol making this a recurring problem it's not a bad trick to learn.