Good idea
Only one little problem...due to the EPA laws once they switch over suppliers to ethanol based fuel that's all you can get.
Here's my tale of woe...
I went through this garbage last year with a new motor, added a Raycor ten mike water fuel filter/separator, and am using marine fuel stabilizer and the motor still took a dump this spring.
Last year with less than 50 hours, the carbs had to be rebuilt and re-jetted, due to this fuel. At that point, the Raycor was added and stabilizer was a standard use item after every fuel up.
During storage this winter the boat was stored with a full tank and was ran for 30-45 minutes at a fast idle every 2 weeks all winter. The boat has a 21-gallon tank and seven to ten gallons of fuel were exchanged every month in the boat to keep the fuel fresh.
A new fuel filter carteridge was installed late March as well
The boat was stored in late October and yesterday I took it out for the first trip of the season and although it ran, it ran like poorly.
Hard to start, poor idle, hesitation on acceleration, loss of power and rpm's at the low end, at the high end rpm's (5000+)it ran better, but still wasn't running as well as last year.
Last season the boat would hit 30 mph @ 5900 rpm this year it barely hit 5900 and only did 26-27 per the gps.
Bottom line is that I have a new boat and motor that I have owned since 5/9/2005 and due to the Yamaha motor and this fuel, it gets to go back to the shop yet again with less than a hundred hours on the motor.
Yamaha sent me a customer satisfaction survey a while back, I saved it until I could take the boat out this spring, here is the "Attached letter" that is going back to Yamaha with the survey.
5/5/2006
I have owned my Triumph 150CC since 5/9/2005 and overall it is a fine little skiff for inshore fishing, the Yamaha 40 four-stroke was reputed to be a good engine although I am more than a little disappointed at its performance to date. The first hint of a problem was last year with the motor was hard starting and refusal to idle until warmed up and it got progressively worse to the point where the motor would die and not run.
The problem was attributed per the dealership to the change from MTBE in California to ethanol mix gasoline in June/July ‘05 here and ethanol’s absorption of water causing corrosion in the carburetors.
The fix was easy, the carburetors were re-jetted and rebuilt (Although getting the jets from Yamaha in Japan took quite a bit longer than expected) a Raycor filter was added with a ten micron water fuel separating cartridge. I think Yamaha should have alerted the dealers to insist on the installation of a filter with the new boat since they knew there was a problem with the ethanol fuel.
I was advised by my dealership to use fuel stabilizer and run the motor twice a month during winter storage. Now here it is 5/5/2006 and after the first fishing trip of the season the motor is unfortunately not running correctly again, it is sputtering, not idling well, surging, and loosing power at low speeds. The fuel filters were changed and the fuel is fresh.
In my opinion the low speed jets are restricted/clogging up again by the way it’s running, once you apply more throttle the rpm’s increase and the surging quits although there is a noticeable lack of top end performance, this is pretty much a repeat of last years problems.
I am impressed with the fuel economy, if I keep an easy hand on the throttle and keep the speed down around 15-17 knots I get an impressive 8.75 per gallon. On one trip, I kept the speed to 15-16 as a test and got ten miles per gallon. Top speed is right at 30 kts @ 5900rpm last year, top speed today was about 26 mph @5900.
In addition, if you were wondering, I would get the same boat again (Although I might go with a different engine)
I’ve owned several different boats in the past with larger motors made by Evenrude, Mercury and Johnson and honestly I must add here that I didn’t have the troubles with those motors that I’ve had with this Yamaha.
I maintain my equipment in perfect order as one’s life can literally hinge on the dependability of the motor with the ocean conditions here when crossing Humboldt Bay bar, having a motor that will not run well places my life on the line.
I would like to add that the Outboard Center where I purchased the boat and motor has been very helpful and 100% supportive on fixing these issues and their service is top notch.
I will be taking the boat back in on 5/10/06.
When the motor is running correctly it is a pleasure to use, however having a motor with less than 100 hours on it and having these kinds of problems makes me wonder if I made the right choice.
To sum this up I am a happy Triumph owner and a very unhappy Yamaha owner at this point in time.
xxxxx
Any light you can shed on the subject without putting yourself in a awkward postition, would be most appreciated.
so your engine should be fine... All of this talk about such fuel blends though, reminded me that I need drain off my fuel water separator bowl 
