idle setting for a Walbro carb

[craigh]

I have an older 3W100 with a Walbro carb and, even after carefull low end needle adjustments, am not able to get a smooth, reliable idle below 1500 rpm. Any ideas?

[Flyinhigh]

In my experience, however limited, these are the first things I would consider:

1. If the engine has relatively low run time, it may still need to break-in; 3W's take a long time and a lot of fuel to seat the rings and get a good, low idle....... this is what I found to be true with my first 3W 150. In the first gallon, I could hardly get below 2000 rpm, but by the fifth, it was ticking away at around 1100.

2. Check the throttle connection to be sure you are actually closing the butterfly and have good resolution between the throttle arm and the throttle servo - you should be able to kill the engine by closing the throttle all the way.

3. Check to make sure you aren't leaking air around the carb block or at the cylinder base(s)

4. Be sure you are getting good fuel flow... i.e - good plumbing in the tank, no plugged filters, and hopefully you won't have to go this far, no blockage in the carberator or the carb screen.

5. If that changes nothing or reveals nothing, call Bobby at Cactus Aviation, Gerhart at Aircraft International, or Ralph at RCignitions

[craigh]

Bonehead that I am, all I had to do was dial the throttle trim setting down a few clicks. I'd been working with servo end travel and the trim setting was the better way to go. Pedro Brantuas, cool guy that he his, helped me with that one today. Now I can actually land smoothly--what a concept!