2003 F90 - REC90 or Ethanol Gas ???

[newboater]

Can I possibly damage a 2003 Yamaha F90 4-Stroke motor by running it on REC90 gas?

I read somewhere that I should NOT run fuel with an octane rating > 87 on a regular basis. It says to check with the manufacturer. The operators manual for my 2003 Yamaha F90 only states that it should be greater than 86 octane.

Does anyone know what E-10 gas looks like and/or smells like when it starts phase separation?

I recently bought a pontoon boat with the F90 on it. After a couple good days on the water, it started leaking fuel from the carbs. I opened them up and they're in bad need of cleaning, so I'm waiting on an ultrasonic cleaner and repair kits. All the jets, seats, etc, look good other than needing a good cleaning.

The original owner ran E10 with regular stabil for the past 11 years.

When I drained the float bowls the gas was a cloudy orange color. It also had a kind of foul smell to it. I poured some E10 I had for my mower into a glass and it's clear. It also smelled a lot better than the gas from the carbs.

So now I also get to drain & clean the fuel tank, replace the fuel filters and most likely all the fuel lines, which I believe are all original. Will pull and clean the fuel pump as well.

[TownsendsFJR1300]

Can I possibly damage a 2003 Yamaha F90 4-Stroke motor by running it on REC90 gas?

I read somewhere that I should NOT run fuel with an octane rating > 87 on a regular basis. It says to check with the manufacturer. The operators manual for my 2003 Yamaha F90 only states that it should be greater than 86 octane.

Does anyone know what E-10 gas looks like and/or smells like when it starts phase separation?

I recently bought a pontoon boat with the F90 on it. After a couple good days on the water, it started leaking fuel from the carbs. I opened them up and they're in bad need of cleaning, so I'm waiting on an ultrasonic cleaner and repair kits. All the jets, seats, etc, look good other than needing a good cleaning.

The original owner ran E10 with regular stabil for the past 11 years.

When I drained the float bowls the gas was a cloudy orange color. It also had a kind of foul smell to it. I poured some E10 I had for my mower into a glass and it's clear. It also smelled a lot better than the gas from the carbs.

So now I also get to drain & clean the fuel tank, replace the fuel filters and most likely all the fuel lines, which I believe are all original. Will pull and clean the fuel pump as well.

Not sure what "REC 90" is. I would put in what ever octane your owners MANUAL calls for BUT NON-ETHONOL. .

The Ethonol attracts water, breaks down quickly and will literally eat up rubber parts from older engines not designed for ethonol.

Yes, it more expensive BUT, in the long run, its cheaper as you won't be doing carb rebuilds, replacing fuel lines, etc.

I would also add a fuel stabiler on a regular basis, even with the the non- ethonol fuel..


BTW, your under cowl Yamaha fuel filter cup may be slightly larger (expanded) due to the ethonol. Mine expanded enough, I couldn't get it back in the base (turned it yellow too).

It was still under warranty, I replaced it at no cost. Went to non-ethonol fuel after that. I also had the fuel line (supposedly new when re-powered) between the transom fuel filter and engine, INSIDEs, literally fall apart.

Luckily I spotted it early, some small spec's inside the Yamaha filter. And yes, it was marine grade,(had Mercury on it)....

[newboater]

Sorry, REC90 or Recreational 90 is a non-ethanol fuel with a 90 octane rating that's sold at Marathon gas stations in my local area.

[TownsendsFJR1300]

Sorry, REC90 or Recreational 90 is a non-ethanol fuel with a 90 octane rating that's sold at Marathon gas stations in my local area.

.
No problem.

I would just check what Yamaha recommends octane wise for that engine.

I suspect you'd be fine with that fuel, but I'd confirm with your owners manual...