Hey folks, I am attempting my first conversion with a 25 cc Homelite engine. Got the flywheel machined down; got a prop hub adaptor; got it mounted on a homemade test stand clamped onto a Black and Decker workmate. Starts just fine and sems to run OK, but it seems like not a lot of range between idle (high), and full throttle (much higher). I've been reading this forum for a while now, and have seen references to low and high speed needles. On my carb, I have a piece of white plastic that surrounds what appears to be a threaded metal rod in a red plastic sleeve on the motor side, and a smooth metal rod next to it, on the (homemade) velocity stack side. Are these the hi and low speed needles referred to? If so, how do I use them properly? Do I remove the white plastic 'sleeve' . Sorry to be so long, but this is my first time. Please be gentle...[sm=confused.gif] Thanks

Hard to say without seeing it. Lets start by saying to remove the plastic to expose the needles. Hopefully you will have 2, a high and a low. If not get a new carb. What is the range you speak of. Are you saying the throttle arm motion? When you set up the throttle pushrod you do it like a glow motor with end points etc. Now for adjusting, I start with the high and go to max RPM then back off slightly. Adjust the low next by leaning until the RPM's max again then back off a tad. You will need to adjust the idle end point as you do this otherwise the RPM will be too high to notice small RPM changes. Check the transition and adjust from there. Some will say to go back to the high and recheck. I will fly the plane and see what it does and adjust from there if needed. Remember that only very slight adjustments are needed. Slight meaning maybe 1/16 or even 1/32 at a time. Once set you will rarely if ever touch it again. Also remove the idle screw from the cover. Not needed.

If your engine came from a leaf blower, you will need a new carb. Most leaf blowers just had a low and high speed and the low wasn't very slow.

Enjoy,

Jim

Actually, motor is from a string trimmer (weed wacker), and no airplane I currently have is really quite big enough to put it in right now. Am currently in the process of acquiring materials for a large SPAD to use as a suitable test bed. Haven't flown power for about four or five years, and only made a few sailplane flight in the last couple. Work and school have kept me off the flying field the last couple years. But I WILL be back.