100LL AVGAS in my bike?

Hey all,

As my handle shows I'm riding a '99 WR400F. I live and work in an aviation town where my access to 100 low-lead (not UNLEADED, just low-lead) aviation gasoline is fairly easy. Is it OK to run non-unleaded fuel in this bike, and will it result in slightly lower operating temps with the higher octane? Is that high an octane and the fact that its not unleaded, any cause for concern?

Any advice or insight would be appreciated!

ArcticWR400,

Check out this discussion thread from racedezert. Although the discussion is directed primarily to race cars, a motor is a motor. It should answer all of your questions.

http://www.race-dezert.com/forum/showthread.php?t=44599

Many years ago when the gas in Baja was poor(and our bikes had Hi comp.) We used av gas 50/50 mix the bikes ran great and cool.

I would just save your money and run premium pump gas

BajaFool;

Thanks for the link... it did explain quite a lot. A nice mix of premium unleaded and avgas (free to me as I work for an airline) will do the trick, and as nobody mentioned the carb or valves getting gunked up I assume it's not an issue. Thanks!

Avgas of any octane is not correctly blended to run in a short intake, high rpm engine the operates at low altitudes, high temperatures, and is subjected to random acceleration and deceleration. It's made for just the opposite; big, slow turning engines that run at very low temps and at higher altitudes. The vapor rates, etc., are completely wrong.

The only truly good reason to run it would be to blend it in at 20-30% with pump unleaded regular IF that was all you could get, and IF the regular exhibited a tendency to ping.

Avgas of any octane is not correctly blended to run in a short intake, high rpm engine the operates at low altitudes, high temperatures, and is subjected to random acceleration and deceleration. It's made for just the opposite; big, slow turning engines that run at very low temps and at higher altitudes. The vapor rates, etc., are completely wrong.

The only truly good reason to run it would be to blend it in at 20-30% with pump unleaded regular IF that was all you could get, and IF the regular exhibited a tendency to ping.

So the fuel could cause complications? I don't race, and the bike has already got balls enough for me... It's just that I have access to it for FREE (our aircraft test the fuel from 3 - 5 different drain points in the tanks and fuel lines for water by extracting roughly a half-cup of fuel... so 1.5-2.5 cups of fuel several times a day from several aircraft being put in jerry cans and then sent away for disposal). I would just take some rather than let it all be disposed of... but I don't want it to cause the bike -- or myself by extension -- any issues.

It could cause lead fouling, but more likely, it would just lead to a loss of power, poor performance/driveability, and a waste of money. It's just the wrong fuel for a motorcycle.

Octane has no influence on temperature, power or speed of combustion, only resistance to detonation. Read:

http://www.thumpertalk.com/forum/showthread.php?p=2827893#post2827893

AHA! Thanks Grey. I'll just stick to the premium pump and enjoy the beast the way she is... and I'll ride the bike also :moon:

Another problem with using gas from the fuel sample points is that they are typically the low points in the fuel system, so they collect water, dirt and other crap...

Another problem with using gas from the fuel sample points is that they are typically the low points in the fuel system, so they collect water, dirt and other crap...

Well, actually the great thing is that we have all sorts of filtering and quality control measures also... ie. water/sediment filters ("no-go" filters) and the like, So I wasn't too concerned about that but you do present a good point... something else to think about. But as Gray mentioned there really is no advantage at all (quite the opposite) to running aviation fuel in my bike. So I just won't do it. :moon:

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