Yamaha 4hp Questions

[guss az]

Hey guys just picked up a new toy its a yamaha 4 hp, My questions are what year it is , air or water cooled, and the motor says it needs 100/1 oil/gas ratio is that right or should i go 50/1?
Motor numbers 4ML hp, GE0, 393190

thanks Guss

 

[RiverRunner38]

Re: Yamaha 4hp Questions

I also have a Yamaha two stroke that says 100/1 oil/gas mixture, but i run a 50/1 mixture just to get all the life i can out of my motor. The 100/1 mixture will make the motor run cleaner but also in my opinion and experiences decrease motor life. 50/1 is the way to go... keep in mind it will smoke a little bit more due to the extra oil, but keep it lubed up and running longer! I'm sorry i can't help you with the year model! Good luck!

 

[wylie catter]

Re: Yamaha 4hp Questions

I have one all so. Mines an 88 model. The only way I could figure that out was go to the parts lists on this site and on boats.net and look for the model number.

I ran mine for the first time today as a kicker. I had to rebuild it as soon as I bought it. Completely rebuilt it except for the crank for $206. Very easy rebuild. Every single bolt is a 10mm.

I'm running 50.1 and it doesn't even smoke. Runs quite and smooth. I want to try it on a jon boat soon.

 

[wylie catter]

Re: Yamaha 4hp Questions

Oh, and mine is water cooled, and it has a thermostat.