Is it possible to......

I have a 98 yz400 and it has high compression and i am forced to run 120 octane fuel which costs me $10 a gallon and i am looking for someone that knows something about switching it over to alcohol which is only $3 dollars a gallon. can someone point me in the direction of parts needed or tell me if its not possible. It is a blast to ride but i am getting tired of it costing so much.

i think it would be a bad idea a few friends of mine run alky in there banshees and when they have there alky carbs on they burn about 2 1/2 times the fuel, as i said "alky carbs" you cant just rejet the carb and make it flow that much fuel. if you did this to your bike you would be fueling up every 2 or 3 laps at best.

if you really want to do it here is a link to who does all my budies work, call them up i know they will be happy to help you out.

http://www.ctracing.com/

i think it would be a bad idea a few friends of mine run alky in there banshees and when they have there alky carbs on they burn about 2 1/2 times the fuel, as i said "alky carbs" you cant just rejet the carb and make it flow that much fuel. [/url]
And, at $3/gal., that equates to gasoline at $7.50/Gal.

You should be able to run a good pump premium, even with 13.5:1. If not, you can buy toluene fairly cheaply at hardware/paint stores, and mix it up to 20% in your pump gas to raise the octane several points. (toluene is already a component of most gasolines) You will need to bump the jetting a little to use it at more than 10-15%, but not radically.

Alcohol is very high maintenance and as mentioned above you will use twice as much gas. The air to fuel ratio has to be much higher with alcohol, that's why it uses so much more. Also, you will probably have to drain all the gas out of the carb and tank after every ride and change the oil.

I have a 98 yz400 and it has high compression and i am forced to run 120 octane fuel

What is your current compression ratio? You should be able to run a good quality 93 pump gas with most stock and aftermarket pistons. You may need to adjust the jetting to fatten the fuel curve a bit, but unless you have some unworldly high compression ratio you probably don't need to run straight 120 octane.

Running alky is not as simple as dumping it in to the tank and rejetting. You will need to either replace the carb or send it out for some rework to flow enough fuel and air to work. I believe alky is also more finicky with regards to temp and humidity when jetting it also. It will lead to a lot more maintenance and it doesn't keep very long.

I have a PROBE custom piston that is rated at 15:1

as said above alky is horrible in humidity is not like gas alky actualy atracts moisture any time your done rididng you would have to basicaly hook an iv system up to it and run straigt gas through it just to clear it all out of the motor and carb or the next day you will have a rusty watery mess. as i said i saw all the maint. my neighbors had to do to there bikes and they where just hillshooters for glamis i couldnt imagine doing this on my bike with how much i ride thats why they had reg. race gas carbs and alky carbs because its a pain in the ass to run the stuff.

P.S. you would be looking a a couple hundred to do the carb work, IMO just buy a reg piston and ride.

I have a PROBE custom piston that is rated at 15:1

As Gray said, you can mix in some toluene to raise the octane rating a few points. I know a guy who adds some toluene to his Dodge RAM when he takes it to the track and uploads a very aggressive tune. He doesn't have any problems with the engine (the tranny is a whole different issue:bonk:)

If it was me, I would replace the piston with either a stocker or something with a 13.0:1 or lower ratio. Just to save a lot of time trying find the proper fuels.

I know that my '00 426 has a stock 12.5:1 piston, and I have no problems running pump premium (93 octane).

Just my .02 cents.

Alcohol = different ignition timing as well. Not easy on a bike.

you could alway put a differant piston in it and rock and roll.

If you NEED the extra power, upgrade to a newer 450. You would save enough in gas to justify the cost. At $10 per gallon ($6 more than a stock 450) your ROI would be about 1000 gallons or 20000 miles. That's without even getting into the savings in maintenance.:thumbsup:

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