Sour fuel in Yamaha 150

[rickclark]

For the first time in 20 years of ownership my 150 Yamaha O/B won't start at the beginning of the season. Thinking back, I forgot to add stabilizer to the fuel and run it up into the carbs before storage as I ususally do. Drained the tank and filled with fresh fuel, but it still won't start. Thinking I still have sour fuel in the carbs. Can I just keep cranking the engine until I get fresh fuel in the carbs? Yamaha dealer says this is dangerous because blocked jets may "lean out" the gas and burn the pistons from lack of oil. His answer to my problem is to rebuild all 3 carbs @$150 each. I welcome any other solutions to getting this O/B started without having to rebuild the carbs.

 

[rodbolt]

Re: Sour fuel in Yamaha 150

if the carbs are varnished YOU CAN lean out and smoke a piston.
150 bucks a carb is rather steep unless they are using full kits which are rarely nessasary.
typically you can get by with only a claening and fuel bowl gaskets.
replace the lift pumps at the same time as the acidic fuel will eat the diaphrams and then toss a rod.
but DO NOT attempt to run the engine long enough to clean a carb, will pop a piston long before they get cleaned.

 

[ENSIGN]

Re: Sour fuel in Yamaha 150

Put some clean premix gas in a spray bottle,spray some in the carbs and see if it starts.DO NOT USE STARTING FLUID!!! And make sure the lanyard is connected

 

[rickclark]

Re: Sour fuel in Yamaha 150

Ensign, thanks so much for your input. I did as you suggested. The O/B fired on the second round of priming and runs just as good as it ever did. (I drained the tank and filled with fresh fuel and installed a new inline gas filter first.) Thanks again, I appreciate your sharing your knowledge with me.