Alcohol Conversion

32 replies to this topic
  • Carbon450

Posted March 29, 2006 - 12:56 PM


I am with you on this on Tyler. To hell with the guys that don't believe in more power. There has been a consistent belief that alcohol makes a 20% increase in horsepower in any engine. I am looking for someone who has done this so I can prevent myself from going through my engine (again) My bike is strictly for hillclimbing not for hopping logs in the forest. I think the atv guy have the answer. Sudco doesn't sell a kit. Maybe I talked to the wrong person. Any ideas?

  • MotoGoalie

Posted March 29, 2006 - 01:02 PM


Won't you also got through fuel so fast that you might only get 15-20 miles or so out of your stock tank?

  • kid on a 426

Posted March 30, 2006 - 09:14 PM


Won't you also got through fuel so fast that you might only get 15-20 miles or so out of your stock tank?

Exactly what I was thinking. Because alchohol is way less explosive than gasoline so it needs to be cunsumed at a higher rate which is less mpg

  • Matty05

Posted March 30, 2006 - 09:29 PM


We used to run mikuni conversions on the old speedway bikes. If you didn't run soldered brass floats, you developed problems with the plastic ones getting fuel logged. Methanol is hard on certain plastics. We also had to run tygon fuel line; the rubber stuff wouldn't hold up. The float needles used to corrode out in the old methanol amal carbs.

Yep, look to the speedway guys for assistance!

My father races what you guys call mini sprintcars, they are methanol.

You need to clean out the carby after every use, otherwise, it goes to jelly.

everyone uses 500cc rotax twins here to power their cars, or the "solo" speedway bike engines such as Jawa and Godden. These engines are 500cc.

  • Matty05

Posted March 30, 2006 - 09:30 PM


Exactly what I was thinking. Because alchohol is way less explosive than gasoline so it needs to be cunsumed at a higher rate which is less mpg

And the problem is???

  • kid on a 426

Posted April 03, 2006 - 12:14 PM


And the problem is???

No trail riding. Can't run a moto so whats the point? Probably go through a tank in an hour

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  • Carbon450

Posted April 12, 2006 - 11:59 PM


I run speedway on a Weslake.
What I have found on alky since my last post:

Stoic on gas 12.7:1
Alky 6.1:1
Higher consumption but less throttle use so it is a slight balance. You will burn 3/4 tank gas per 1 tank alky

I have a 13.5 piston and the conversion only takes a jet and a tank of alky.

I figured my 450 would need a 230 to be on the safe side. My weslake has a 38mm carb and a 220 runs perfect at sea level.

We are looking at another 3 horse alky maybe 5 with the right pipe but this might be high.

A smokin port job gets you 2 on the very top with a huge loss on the bottom!

I think alky is the way to go

Maintenance is easy, not the flush or you die stuff. after your weekend, drain the tank then run petro through. Or pull the carb and spray wd into the intake and the plug hole.
I have left my weslake unattended for months at a time after a season and nothing happens further than a good cleaning of the carb.

Power junkies only please! :thumbsup:

  • Diode663

Posted April 13, 2006 - 05:21 AM


I also have a 450 with the 13.5:1 piston and Im intrested in this too. From my understanding you make all the jets 40% bigger, have to wieght or bend the rod on the float seeing as alky is more dense then gas so it will have the float sit higher for a given level, and advance the timing. I have a big gun rev box so Im confident that the timing is advanced a few degrees. Also it doesnt seem like it would hurt to go a range hotter on the plug.
Sound about right? The only problem is finding methanol.

  • Carbon450

Posted April 13, 2006 - 10:41 AM


The only issues I have come across with the float is the use of plastic. Supposedly the plastic float is not correct for the conversion but I have a plastic foat in my weslake. Ron Woods has a conversion for the TM carbs. Maybe he has the stuff for the FCR. list.pdf

  • PumpkinHumper

Posted April 13, 2006 - 12:36 PM


Another thing to keep in mind is trying to get it jetted. You cannot tell at all by the plug how the engine is running when running Alcohol. Rich or lean the plug looks the same clean as a whisle. You have to tune the engine by ear. I have heard of many people blowing up engines trying to get them tuned in correctly.

We have folks around me that run alcohol up to Silver Lake sand dunes. Its a pretty common mod for sand running. Yep it is corrusive. Yep you have to drain the tank after every days ride. Yep you are going to go thru lots more fuel. But it works.

I hear that Alcohol has a higher water content in it which helps with detonation when you run the higher compressions.

  • jirondenis

Posted April 08, 2007 - 06:16 PM


I put a 34mm keihn on my bike with a 220 main and methanol in the tank. How do I make sure it runs right?

  • Chrome Speedo

Posted April 09, 2007 - 08:57 AM


Another speedway guy here...

I'm curious as to what kind of oil are people running in moto bikes with methanol?

  • YzGuy79

Posted April 09, 2007 - 01:27 PM


......The only problem is finding methanol.

Or just about any sprint car track and club will sell you 5 gal.

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