What Gas?

[Tim S.]

I've done quite a bit of reading on the ethanol problem and I'm still confused.

Just bought a used 2001 Yamaha 100 HP Carborated Four Stroke. The engine runs great idle's great. (does however take a couple minutes to warm up)

From what I've read carborted four's have a greater tendency to get a clogged carb because of water build up. The water build up is caused by gas with ethanol in it. I asked the local Yamaha dealer what gas they would use in this engine and they told me to use whatever gas the previous owner had been using...however they suggested to run the Mercury ethanol additive with the gas. The prevous owner had been using low octane gas with ethanol.

So here are my question, what gas is best for this engine?

Low octane gas with ethanol and the Mercury Additive? Or
Premium gas with no ethanol and no Additive? Or
Premium gas with no ethanol + the additve?
Will running high octane gas hurt the engine at all?
If it wasn't for price would everyone just use the gas with no ethanol?

Thanks for the tips!

 

[Chris1956]

Re: What Gas?

You need to look in the owners manual or service manual to see what octane is recommended. I would think 87 octane is recommended, but am not real familar with Yamaha OBs. If the water content of the gasoline is low, you do not need any additives. If the water level of the gas is high, buy gas somewhere else where it is low. Additives will not save waterlogged gas.

Usually running higher octanes will simply lighten you wallet. it will have no effect on the motor. E10 is a perfectly fine fuel.

 

[Silvertip]

Re: What Gas?

This Ethanol misinformation just won't go away. First be aware that higher octane fuel is not better fuel. It is higher octane. Higher octane does not make it better fuel and contrary to popular belief it does not make more power. It is fuel that burns slower to retard detonation in engines that REQUIRE high octane fuel. You do not have an engine that requires high octane fuel. In fact the additives in high octane fuel may indeed be harmful over the long haul. So you now want to exchange one "potential" issue for another. Next, understand that any fuel gathers water through a term called "condensation". Airplanes have valves to drain off water and I've seen a lot of it drained from a relatively small tank of av-gas. All high octane fuel will do for you is cost you more money. Add a water separating fuel filter. Fuel treatments are available in many forms but the varieties marketed by the engine manufacturers and those from Stabil, SeaFoam, StarTron and others are ok to use. Note I said fuel system treatment. The fuel is treated to prevent gum and varnish from forming in the FUEL SYSTEM. That's the only way to protect the system. Keep the fuel system clean and go boating.

 

[robert graham]

Re: What Gas?

I've done quite a bit of reading on the ethanol problem and I'm still confused.

Just bought a used 2001 Yamaha 100 HP Carborated Four Stroke. The engine runs great idle's great. (does however take a couple minutes to warm up)




From what I've read carborted four's have a greater tendency to get a clogged carb because of water build up. The water build up is caused by gas with ethanol in it. I asked the local Yamaha dealer what gas they would use in this engine and they told me to use whatever gas the previous owner had been using...however they suggested to run the Mercury ethanol additive with the gas. The prevous owner had been using low octane gas with ethanol.

So here are my question, what gas is best for this engine?

Low octane gas with ethanol and the Mercury Additive? Or
Premium gas with no ethanol and no Additive? Or
Premium gas with no ethanol + the additve?
Will running high octane gas hurt the engine at all?
If it wasn't for price would everyone just use the gas with no ethanol?

Thanks for the tips!

Run regular pump gas 87 octane with or without ethanol, Stabil or Seafoam Stabilizer, and a fuel/water separator type cartridge filter, learn to drain your carbs a couple of times per year, especially during lay-up periods of several weeks or months, doing these will eliminate most fuel related issues.

 

[Cannondale]

Re: What Gas?

This Ethanol misinformation just won't go away.

And I swear it seems to be getting worse, if anything. I see comments like "Maybe even the best engineers can't figure out how to build an outboard to work with ethanol." (This about a current model Yamaha outboard......really.)


Strange thing is, I've got a 1985 Chrysler convert that mentions ethanol's use....and permits it. I've got a 1991 outboard that mentions ethanol's use.....and permits it. You'd think after decades of ethanol in the fuel supply system, it wouldn't be an issue, but the hucksters, the sadly misinformed and/or gullible, and the irresponsible fear mongering just won't cease. Maybe we should start calling the FUD spreaders of the evils of ethanol something along the lines of "birthers", along with all the negative connotations associated with that term. Just cannot think of something catchy right now.

 

[Brewman61]

Re: What Gas?

I live in MN, which I believe has the highest per capita rate of boat ownership in the entire country. If not top, then very close. We also have and extremely powerful lobby for ethanol, and have had E10 fuel around for a couple decades. My buddy has a 1990 Johnson 2 stroke 115. It's compatible with E10. He's put pump grade regular E10 in that motor it's whole life, and he's not using any additives, perhaps stabilizer for off season storage, but that'd be it. He has no problems using the corn stuff. And he's a bit on the lax end of things, probalby like most of the people I know. I'd think if E10 was terrible, we'd be hearing the outcry here due to the commality of the ethanol coupled with TONS of boats. But we really hear nothing much. YMMV.

 

[5150abf]

Re: What Gas?

The only affect running high octane will have is draining your wallet faster, it is intended for high performance high compression engines which you don't have.

That si one of the biggest wives tale out there si that you get more performance from high octane gas when in reality is si no better than regular unleaded when it comes to performance.

As tha others have said, run regular unleaded, with or without ethanol and drain your carbs if the boat is going to sit more than a couple weeks, run at least a fuel filter bt a seperator is best.

By the way, I really think making fuel from food is the dumbest thing I have ever heard of, it isn't the answer.

 

[Chris1956]

Re: What Gas?

OK Cannondale, produce your Birth Certificate. I suspect you have liberal leanings.....