PDuck

I need some help on this one. I have a new XL46 with standard needle that I am trying to break in. My problem is that the engine only runs at high speed. adjusting the needle makes no change in RPM. It will not idle and to get it to run at all the throttle trim has to be all the way up. Anything below the trim setting and the engine stops. If I try and throttle up the engine stops. Do I need to send the engine off for service or am I doing something wrong. Thanks PDuck

FHHuber

Sounds like either a bad air leak, a clogged fuel lne or a VERY out of adjustment low speed needle.

Check the fuel lines for any pinholes, including the clunk line inside the tank.
Pull the carb and check that its got an O-ring, then put the carb back, and WHILE PRESSING the carb down, tighten the locknut. (big air leak point is at the carb to case connection)
Pull the man needle valve out and check that its O-rings are there and not shrunken. Look inside the needle body and see if there's dirt in there.

If that doesn't locate the problem... open the idle needle 2 turns. (it will be rich) The idle needle is centered in the side of the carb barrel on the same side as the throttle arm. (the needle should be just about flush with the throttle arm... if its in more than 2 turns from flush, its too far in.)

Somewhere, you've got either a fuel blockage or a major air leak. (I'd bet on a blockage... dirt in needle assembly is highest probablility)