I purchased 2 DLE 20 engines some time ago. I fitted one into a Seagull Yak. The engine was correctly run in and then flown twice in the aircraft. It ran and performed faultlessly. It was then left to sit for 2 months. Now comes the problem. The engine starts easily, idles very nicely but wont rev past half throttle. The engine appears to starve for fuel. So, this is what I have done to try to identify and correct the problem.
1) Check the fuel tank, fuel lines and clunk for blockages - None found and all lines are clear
2) Swap the carb with a new one straight out of the box - No difference. Problem still exists
3) Swap the electronic ignition unit with a new one straight out of the box - No difference. Problem still exists
4) Swap the reed valve with a new one - No difference. Problem still exists
5) Change the spark plug. Replace the stock DLE plug with a Champion equivalent - No difference. Problem still exists

The needle valve settings have been adjusted but the problem is still there. I am now at a loss to know what to do next? Has anyone had a similar problem or am I missing something?

Thanks

I'm no expert, but it sounds like a pulse leak. Check the hose going from the carb to the case, as well as the fittings.

I had a very similar sounding problem recently with my G20, which like your engine had been working perfectly and was left unused for about four months. The engine would start just like normal and run perfect at a max of high idle all day, but any attempt to increase the throttle would cause it to immediately shut down. I did all the checks you did plus some without any success, and after several days of hair pulling and head scratching it turned out to be a partially clogged felt clunk. Replaced the clunk and all was well again.

Karol

Hose.....what hose?
This is a DLE20.

Swap out the battery &/or replace the clunk/pickup.

Battery may be failing & no longer delivering the juice needed at higher RPM's.......&/or the fuel pickup is restricted/plugged and starving the eng for fuel (even though you say it's fine, change it anyway).

After checking the fuel as you did, I would be looking at the battery (or should I say power to ign. module?) as well.

It's kinda crazy how those ign. modules work. Higher throttle settings require more power to the module. If it's not available, it doesn't just shut down, it does it's darndest to let you know about the low voltage by running so crappy you land it....

The battery is something I havent changed yet! I will try that.

plus 1 on the battery, if its not that look for an air leak. have you checked the butterfly is opening in the carb to full?

Which brings up the rare issue of a loose butterfly screw!
A few have had that issue, something else to look into.

{Don't think 2 carbs would have the same issue though}

I still lean toward a bad ign battery.