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Old 03-05-2008, 08:13 PM
  #20  
jimcork1
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Default RE: Quadra 52 won't run under 3500 HELP

Ok,, latest update. I added a choke plate to the inlet of the carb. With the choke I can close it fully spin the engine over until it pops,, open the choke 1/2 and start the engine. This is repeatable and easy to do,, Then once it is running I open the choke and it will go to full power,, but,,,,,,,,,,,,,,, It will idle slightly slower,, [X(] So I measured the throttle opening in the carb at 11/16 and the choke plate at 1/2. So this means a smaller opening improved the idle. So I decided to do a test. I made a plate of sheet metal with a 3/8" hole and mounted it under the choke plate at the air intake. Started and retuned the engine. The engine lost 400 rpm top end,, which didn't suprise me. What did was that it would now idle at 2900 rpm and even as low as 2700 rpm. So I decided to fly the bird. Take off showed the rpm loss but it flew well until the choke plate vibrated closed and killed the engine. So the brick bird (read really heavy plane) deadsticked into a 15mph wind. and landed in the briar patch at the approach end of the runway. Minor puncture in wing was all. I ordered a rebuild kit for $4.85 for the carb which is all the rubber parts. I will install it tomorrow and confirm if this makes an idle difference. I will also check to see if the throttle plate is correctly installed. I plan to install the choke plate minus the restrictor plate (woo woo sounds like nascar). to see if it will idle and perform with new rubber internals.

If this doesn't work I am considering the WT76A I saw on ebay at roughly $12.00 as a test replacement that truck racer found. I am not above buying a new carb such as the others mentioned but I am getting a bit frustrated with the no idle situation. Given this really is a new engine. What about mounting the plug vertical vs down. think that would make any difference possibly plug flooding inverted.

Well tomorrow will be another day and we will patch the wing and try again. The wing would not need patching if I had a reliable engine. Jim