MacGregorSailors.com

Dimitri-2000X-Tampa wrote:You are right about AVGAS, it is very clean. You get some on your hands when checking the tanks and it just evaporates right off, hardly leaving any smell at all compared to the dirty auto gas (which I expect is exactly the same as what is sold at Marina's for 50% higher prices) which you have to wash your hands 3 times to get the smell off.

However, AVGAS is also much higher octane (I think around 100) so that means our outboards are probably not designed to run with it and maybe it could cause damage without engine modification.

I can't imagine 100 octane gas would cause an issue..octane is just a rating of pre-ignition..in most of our standard outboards, there would be no benefit using higher than is needed.

Also, I thought the general public couldn't buy avgas anymore (easily)..or is it leaded avgas I am thinking of?

Has anyone had any issue with carbs getting gummed up with bad/old gas? I have never run into it...just wondering if it is more in theory..or actual practice. Then again, I always use a fuel staibilizer when storing motors.

I had my carbs cleaned on my Nissan 50 HP, and was advised by the mechanic that storing the engine level is advisable. His thought is that the floats should be level during storage. Ive followed his advice with no engine problem.
I keep "stabil" on hand, and do not let the gas get over 3 months old, and empty the old gas in the vehicles. So far, no further carb problems.

It's no secret that I'm not fond of my Honda 50, It's a candy-assed outboard needing regular attention. Having lived with it for over a year I've talked to professional crabbers that use them and here' my conclusion.
They were designed primarily for low emissions and high fuel efficiency, and high duty cycle. The orifices in the jets are smaller than a pin. If left unattended it's arteries (jets) will quickly clog if the fuel evaporates, so the key to getting good service out of a carbureted Honda is to either use it a lot (fishermen, crabbers), or make sure it's put up properly if it'll set for any length of time. Meaning, drain the bowls, The bottom setscew drains the lowest carb bowl and probably the other two higher ones. Then run it out of fuel. Keeping the engine vertical when not in use and doing that I haven't had any more gelled-fuel problems.

Night Sailor's story of keeping gas for SIX years rings true for me too. I always add a little STabil into each 6-gal tank during fill-up then never fuss with it - they run dry or not. They get topped off again - whenever. The Suzuki 60 is stored up, down, around, not necessarily twice the same. My only fuel problems were the gas tanks and fuel line - not the gasoline or engine.

I have 3 tanks aboard at all times but I tend to favor the Duratanks, using the larger Suzuki tank very infrequently. Just a guess - last time used was 2 years ago. There was only a tiny reserve in there (< gallon) for that entire time. I started it yesterday on that very old gallon of gas and idled about the marina. It started instantly and purred smoothly at 400 rpms. It never stalled, never even threatened a stall. I attribute this to Stabil (maybe) but more to electronic fuel injection -
regrets if you're unfortunate, but carburetors (automotive or outboard) are from the last century.

Conclusions:
- Stabil'd gas just doesn't go bad.
- Suzuki EFI is amazing, requiring no special thinking or tenderizing.
- All these issues, warnings, drainings and level storage are basically carburetor TLC.

Make sure you do what the factory recommends on winterization.

Please see your manual. The gas in the lines and motor is as important as what is in the tank.

Drain the gas tanks into your car when done.