Has anyone tried running their KLX-250S on E-85 gas? Did you have to do anything to make it work? Did you need to re-jet the carburetor?

Thanks!
Sid

 

I'm interested in this as well. If anyone has any info, please let us know.

 

First, you'll need to run a lot richer. To the point in which the carb may actually be too large or not provide enough vacuum for the airflow rate. Remember Alcohol contains some of the oxygen needed for complete combustion, so less air is needed. Second, The ignition timing may need to be changed. Possible advanced, I think the ethanol burn a little slower. Otherwise, it should work OK. I know in college I saw 600cc sportbike engines in small open wheel racecars running on E85. They were using custom made fuel injection systems however. I also don't know if the peak cylinder pressure is any different when burning E85. IF so, the compression ratio may need to be lowered or possible raised.

Most flexible fuel cars I've seen are fuel injected, low compression, low output OHV motors in GM SUV's.

 

E-85 is 85% ethanol. The owner's manual on page 40 states that fuels up to 10% ethanol can be used.

Understand that while these fuels are cheaper, they also require more to be burned to make the same amount of power. While I think this is a step in the right direction, there is still more left in the journey.

I remember when I was helping a friend prep his modified dirt race car to run alcohol. The first step in jetting was to REMOVE the jets from the carb. Then we had to drill the holes out larger so that the carb would flow enough fuel to burn properly. And this was in an engine with 14 to 1 compression. That was methanol not ethanol.

 

I tried it in my 09 klx 250 today...

Why cause it was $2.85 a gallon and I had to try it...I just had to find out....

Ran great didnt seem to knock and had the same power..But she wouldnt idle....Got so bad I had to hold it at 2k rpms at a stop to keep running..If I tried to lower the idle to 1800 the acr/Icr or whatever it is I think was knocking.....Drained the tank within 8 miles of use......All is well now......Ohhh the fumes coming off the pipe were nasty too...Like a sweet burnt liquor taste....

Rocco

 

motoguy128 knows this issue pretty well. Ethanol is a different animal than gasoline. The bike won't idle because the air-fuel ratio is not stoichiometric at low speed (Google it). And do but the idea that Ethanol is cheaper - it isn't. The more of it you use the less the fuel economy.

 

+1. What's the point.
I use BP Ultimate in car and bike. 98 RON
They run much better IMHO.
WA says NO tho Ethanol in fuel.

 

Next someone will be asking about an LPG conversion for the little mean greenie. WTF!

 

Yeah...I just did it to do it....

Figured at the worst Id have to do a big bore kit early if something in the motor went bad...................winkwink

Rocco