Hi All

I have had a few enquiries regarding engines leaning out after a jump, this will be beneficial to racers and bashers alike. What you find is when you gas it off a jump the idle rips up bringing the nose up, then you compensate with brake to tip it back .. sometimes this dosent always work out.. Especially those with sensative brakes. Most people will notice this happen suddenly after a few litres of run time and go everywhere looking for the leak ... Everywhere but the CARB BOOT ! ( dramatic orchestral stab ) OOOH ! pennies dropping ?

What happens is the carb boot is probably not made of a quality nitrol base and will soften and expand , this can happen on any engine as it is expensive to make one from nitrol .. about 11 cents more per unit !

SO ! what you need to do is seal the carb boot with a small thin cable tie where it reaches the carb stopping any air getting in ... You can put a dab of silicone around the base before the cable tie if you like , this should eliminate the problem , if it dosent then check it closely for tears and replace.

NOW ! why does it cause this problem ?

What happens is when you jump you are essentially clearing all excess fuel out of the engine , leaving not much in there, when you are in the air and the throttle is at neutral its closing the carb. The residual suction of an empty engine scavenges for fuel, if the boot is loose the air will be re directed through the side and by pass the inlet . that suction is wasted and creates a lean engine till you blip it again.

Now there are other problems that can cause these symptoms so make sure if you have it to check everything .

Hope this helps !

Cheers MassiveMods