TRX250R.ORG

Workshop => Carburetor, Intake, and Exhaust => Topic started by: chrisr on September 05, 2013, 10:56:38 AM

Title: Racing fuel questions
Post by: chrisr on September 05, 2013, 10:56:38 AM
Decided I'm going to make the switch to straight 110 octane race fuel.  I had been using 108 octane "pump race fuel".   I want to get away from using anything from the pump and start buying the 5gal cans most fuel companies offer. I'm looking for a little guidance as to what fuel I need to use......oxygenated or non-oxygenated?  Also looking for a baseline to start jetting from.  The engine has no port work, a cool head using a 20cc dome, Boyesen power reeds, stock 34mm Keihin carb and FMF pipe.  I'm in South Carolina with a elevation of 136ft above sea level.  I'm new to the Keihin carbs and their jetting numbers and looking for a starting point.
Title: Racing fuel questions
Post by: C-Leigh Racing on September 06, 2013, 10:10:21 AM
Do not use oxygenated fuel for several reasons. To many problems & even as much time to explain the reasons.

The main thing to think about on the gas used, how high the engine is building compression to & what jet sizes you'll need to keep that piston cool.
List the engines compression when cold & then when hot.
Neil