What fuel octane are you running?

[Alan Schlosser]

I've been running ethanol free gas for years now in the bike, snowblower, 2 cycle equipment and my lawn tractor. It's at several stations around here. I actually have seen an increase in MPG on the bike when I started using it. But the most interesting thing is that with the lawn tractor, when it was extremely hot out, would vapor lock when I tried to restart it. The problem seems to have gone away when I switched to non ethanol.

[KEITH KRAUSE]

I appreciate the replies. I have had zero luck in using Sta-bil, even at twice the amount recommended. I tried it for several months. My bike is generally warmed up for 7-10 minutes every 8-10 days or ridden about 10-15 miles in that same time frame. I think the other problem is my garage gets so hot from late May to September...well over 100 degrees. Fuel cleaners don't help either. After cleaning the carbs they start showing problems with the pilot circuit in a few months. At some point the throttle (slides) actually begins sticking and it's game over.
The Wiseco 1085 piston kit raises the stock compression ratio from 9.2:1, to 10.25:1 I've tried to find info about the correct octane to use for a given compression ratio but there's no simple answer. To many variables enter into it.
I could try the 88 pure gas here and if I notice pinging then I "think" I can mix in some octane booster and the bike will be happy? From what I've been reading, you cannot always hear pinging, so I may just start using the octane booster regardless.
That brings up another question: does anyone here use octane booster? What brand or does it matter? Does it really work or is it like some fuel cleaners where you have no idea if it's doing it's job? Thanks for any help!!

[Big T]

My 1085 runs fine on 87. It will ping once it gets to be 100 degrees or so.

I put pure in it before winter storage

[Nessism]

If the engine is knocking you will see pitting on the plugs. You might want to pull a few of them and look close with an eye loupe.

Personally, I'd try that 88 pure gas along with Sta-Bil marine formula. Go heavy, double the standard rate if the bike is going to sit. Not only does it help against varnish formation it also helps protect the inside of the tank from corrosion.

[Steve]

OK, I think I have found part of your problem.

My bike is generally warmed up for 7-10 minutes every 8-10 days or ridden about 10-15 miles in that same time frame.

The problem is that you are only WARMING the bike, it needs to get HOT. It will never reach proper operating temperature sitting in the garage, and it needs to get to proper temp to eliminate condensation. That might not show up so much in the way it runs, but it certainly does not help longevity. Your exhaust system won't be getting warm enough to eliminate all the moisture, so it will rust out from the inside. Your oil will not get warm enough, so all the moisture will mix in with other contaminants in the oil and turn to acid.

Your best bet is to treat the gas, park the bike and ignore it until you are ready to ride. 15-20 minutes would be a bare minimum. Longer is better, for the bike and for YOU.

.

[alke46]

What Steve said. Only thing I would add is if you know the bike will be sitting for 2 weeks or more at a time, best thing you can do for it is to drain the carb bowls.

[wymple]

I run ethanol in everything I own, always have. I do not let it sit for 3 months, tho. Ethanol cools the intake tracks better than a regular gas-air mix, and my lawnmower in the heat especially likes it.

[Shin-Ken 1074]

Here in Australia the fuel is RON 91, RON 95 or RON 98. As all Japanese built 4-stroke motorcycle engines since 1976 are designed to run on unleaded it depends on the price at the bowser on the day as to which fuel goes in the tank. Most times I tip in RON 95 but this week it'll be the 91 due to the price. AUD $1.62 / litre for 91 and AUD $1.86 / litre for 98.

Converting AUD $ to US $ and litres to US Gallon on fuel price today that would make RON 98 US $4.99 a gallon.

I often see here on the Forum where owners have issues with gummed up carbs or other fuel related issues after leaving the bike sit for a few weeks. I was in contact with a mate of mine here on the Forum (Mass.) recently and he has experienced fuel related carb problems. Does US fuel have additives to cope with the seasons? The reason I ask is a bike can sit for months here in Australia and as long as the battery is charged the bike with fire up on third or fourth hit of the button and run just fine. Longest I have left a bike sit was 9 months and after dropping in a new battery it fired up just fine. She was a running bit rough at first, seeing as the fuel was pretty stale by then but a quick trip to the servo and topping up the tank with fresh fuel got her purring.

Cheers.

[wymple]

Some of you guys might have short memories. I grew up with 50's & 60's cars, and long before ethanol there were lots of fuel related issues. There is nothing new about gummed up carbs, rotten fuel lines, bad fuel pumps, etc. Lots of rotten hoses, in particular. With modern fuel injection, especially, things are metered in increasingly small and very touchy amounts. That should lend itself to even more fuel related issues, but hasn't that I can see, so I think fuel quality is doing quite well, overall.