Whaler Central - Boston Whaler Boat Information and Photos

Posted by pederj on 10/26/10 - 6:59 PM

I purchased a 2 hp yamaha motor to put on my boat as a kicker motor (see the last picture on my personal page). Got a great deal on it and it runs like a champ. The former owner put a little gas and oil in it so I could test it. He mixed the oil/gas at 50:1. The motor says 100:1. Is this little bit of 50:1 going to hurt the motor?
Thanks,
John

Posted by bmw90w on 10/26/10 - 7:46 PM

I have never heard of 100:1 after break in. Every 2 stroke I have ever owned is 50:1. I would double check that manual!

Posted by Gamalot on 10/27/10 - 4:45 AM

100 parts of gas to 1 part of oil is questionable. 50 parts of gas to 1 part of oil is closer to standard and is twice as rich of an oil mixture so I would not worry about damaging the motor with a higher oil content. If anything, it might foul the plug and produce a lot of blue smoke.

As BMW said, check your manual or contact Yamaha because I have never heard of a 100:1 ratio in any 2 cycle engine I have ever owned.

I do have an ice auger that says right on it 24:1 which is a little better than 4 times as much oil in the gas and it ran terrible. Techumsa finally came out with a bulletin telling us to go to 50:1 and it runs fine.

Gary

Posted by Derwd24 on 10/27/10 - 5:03 AM

I'd never seen it before either until a friend picked up a used Yamaha 15 that's about 8-10 years old. Said on the motor and in the manual 100:1 so I called the local dealer and they told me to just mix at 50:1 I think using Ring Free and/or decarbing often is a good idea at 50:1

Posted by Tom W Clark on 10/27/10 - 8:07 AM

Yes, OMC and Yamaha adopted a 100:1 ratio on some models in the late 1980s. The motors worked fine but there was not enough residual oil left on the cylinder walls for motors to sit unused for any period of time.

So they reverted to the 50:1 recommendation. Unless the motor is used daily, I'd go with 50:1.