ORIGINAL: BOUND_4_HELL
ORIGINAL: Bob Pastorello
Gep - your procedure sounds like it's fine, and should be getting you where you need to be.
I'd contact your seller, and see if you can get a different complete CARB to try. Unless you want to dig into it and start troubleshooting the "pop off" pressure on the metering needle lever assembly.
Unless you are experienced with setting that lever, I don't recommend going there; you can end up with a carb that doesn't run at all, and risk the seller saying "you did it".
PM me.
Thanks for the suggestion Bob, the metering leaver pop off pressure turned out to be my problem with my DL50. I did not have a gage so I used the trial and error method. It took me 7 tries and probably would not have gotten it correctly if I had not read the article below on Walbro Carburetors.
It turns out that the needle leaver needs to be lower than the carb base. Mine was at the same height as the base and running rich causing the mid range burble and a lot of mis-fires. I was making adjustments to the leaver a few thousands at a time and getting nowhere. Once I read the article and set the leaver below the base by what looked to my eye about 2 mm give or take, it ran like a top, all the burble and misses are gone. It idles and accelerate a lot better as well, and an added bonus >> I get a couple of extra flight minutes out of my tank.
I also did a spark plug test by running full throttle for a minute and shutting it off. Then I removed the plug and now it's a perfect tan colour.
Thanks
Geppino
Here are the instructions and a photo from the article.
http://www.geocities.com/farellus/idle_adaptation.html
The Metering System is very simple: It consists of a pivoting lever working like a seesaw with a spring on one side and an Inlet Needle (with a red rubber tip valve) on the other.
If you don't have the pressure-testing tool, don't worry, just make sure you clean the carb, blow it dry and use new diaphragms & gaskets and set the Metering Lever height; The resulting pop-off and reseat pressure will be functional as long as you don't damage or modify the Metering Spring:
1) Don't deform or cut the small Metering Spring. If in doubt, replace it with Walbro part Walbro part # 98-320-7 (OEM # 503 28 12-18; WG8 carburetor).
2) Set the Metering Lever at the correct height as explained below.
The height of the Metering Lever on any diaphragm carburetor is critical for controlling when and how far the inlet needle 'pops' open, thus configuring the engine's acceleration characteristics. If the Metering Lever height is set too high, it may create a rich condition, while a Metering Lever set too low may create a lean condition. The height of the Metering Lever must be 1.7 mm or 0.067" (WG carbs) and 1.45 mm or 0.057" (WB carbs) below the edge of the carburetor body. Walbro sells a calibrated brass plate gage to be used as depth meter (Walbro item # 500-13-1) available through most power tool shops.