Posted by Vic on August 07, 2002 at 05:52:16:
In Reply to: 98 w Jardine and Backfire Problem....Help? posted by Charlie Cramer on July 08, 2002 at 04:29:33:
The solution to this problem is to run 93 octane
fuel, and back off that idle speed.The higher
idle speed allows more air to enter the carb when
you close the throttle to shift gears,thus
causing more heat to build up in the exaust
system. Now add the fact that the lower octane
fuel has less "flash" you now have atomized fuel
molecules entering the exaust system.This causes
the BOOM!!
Another solution is to slow down your shifting speed.Remember this little engine takes longer to recover from any kind of throttle movement than a
V-Twin.Close the throttle,pull in the clutch in one smooth movement,shift the gear,ease out the clutch as you apply the throttle.
I think most of us are former dirt bikers who learned how to run through the power band on our
2-strokes as fast as we could! You can't run the savage like that.On a bike with a longer exaust system,those hot engine gases have time to cool before they hit that hot exaust baffle,not so on the Savage! "short bikes = short,hot exaust systems!" The 93 octane fuel really helps out by allowing all of it to burn in the combustion chamber,and not in the exaust system.
Another problem could be that you are rapping out
the RPM too high between gears.As the engine raps up to higher shifting RPM than necessary,that fuel mixture gets pretty lean.This also contributes to extra heat.Shift them gears right as you are approaching the top of the Torque curve.this MAKES
your engine use ALL of that fuel being metered through the carb for POWER, not to feed a hot exaust system!
Give her 93 octane, slowdown the shift speed,don't
over rev her,and your KA-BOOMIN will go away providing the carb aint TOOO lean.
The little Savage is the Diesel engine of the motorcycle world.Remember not to run it like a
Weedeater.I've been rollin Thumpers for 40 years,I hope what I have learned can help everyone on the forum. Try it!