Anyone out there experienced with using nitromethane & alcohol? I need some suggestions. I dirt drag at a 200 ft. track. My quad is a 250 Trailblazer. My dad's done a lot of work to it. It's been bored .060 over, flywheel lightened about 16 oz, race ported, V force reeds, 35 mm Lektron alcohol carb, drag pipe, etc. I know of others with the same bike & modifications using it & getting a big increase in speed & power. We heard 10% mix. So that's 12.8 oz of nitromethane to a gallon of alcohol. We tried that, but my bike wouldn't run right or even idle back down. So we're down to 4 oz. to a gallon alcohol. It' ll run okay, but not much more speed than before. So is our compression too high? Should we get another head that's not been modified & run the 10% mix?

Ladybug

 

Nitromethane contains a very high percentage of oxygen. At 4 oz's a gallon it would be a must to add more fuel along with the added oxygen. The savest way to run nitromethane is to jet way up on your main and add 1 oz at a time doing a proper plug check after each oz. until your plug is were you need it to be then check your midrange and see were you are on your plug there and jet according doing a plug check at midrange until it is were it needs to be. After both are were it needs to be you should have gained a considerable amount of power. If you were just adding nitro and not rejetting it was more than likely leaning way out and you were actually loosing power ecspecially on top end. If you are jetted properly with nitromethane it will give more power everywere. If you use this procedure you could end up with more or less nitro than you intended to run and if you do just go higher on your main and repeat process. We use it on some of our Banshees on alcohol and just at 2 oz's a gallon you see an improvement.( A LITTLE GOES A LONG WAY) Good luck and I hope this might help. Unless you are running very high compression; say over 175 psi you should be ok and if yours is at a higher comp. it may be beneficial to reduce timing. Slim

 

Slim660,

Thanks for the suggestion!

 

Hows it going lacie,its me jonah woods from the henry county fair mud run,remember me,you told me you had a tropey room at the paratrooper ride that night,I was hanging out with kevin jones too at that ride.I have the white and yellow trailblazer 250.I remember you,you have the hot streched out freedom edtion(red white and blue) trailblazer 250.I think you got like 1st that night.

 

Another thing you could try is acetone.I couldn't run 10% nitromethane until I added 5-7% acetone.It has been a year or so since I have played with it but I believe acetone slows the flame speed and prevents wide open detonation (i.e. runs wide open with no throttle+no spark).
Less nitro would do the same but I think more power could be had by using 10% nitro with 7% acetone.
A little off subject but when I play with this stuff again I want to try a four stroke I hear a properly modified thumper can run 60-90% nitromethane.Thats gotta have some kick.

 

We run a 50/50 mix in our dragster that we built back in the 80's. Its got a 500 Jawa in completely custom everything.