Eagle Flyer

My Feedback: (84)

I have a ZDZ 40 I aquired used and had it in a plane ready to go. It started very easily,cold or warmed up and ran great. I let it to a friend for a short time. Now I have it back and it absolutely positively refuses to draw fuel. Has all new fuel lines,twice. Only 3" of line from tank to carb. Have had the carb apart several times and all ports appear to be open. Gaskets appear ok. Here's the real wierd part. Even if you blow in the vent line while turning it over,choked or not,low idle or high, it still won't draw fuel thru the fuel line.Needle vavle sticking? We were able to get it started once by blowing in the vent line for a long time while attempting to prime it. But if we shut it off fuel would bleed back quickly. I found the pressed in fuel inlet not as tight as I would have liked it so I epoxied around it to insure an airtight fit. Still it won't draw fuel. Fuel check flappers in carb appear ok.Crankshaft seal bad causing no pumping action? Any help you can give would be very helpfull. Thanks; JIM

BocaBen

Good to see that I'm not the only one to have a problem to start this engine (just joking!). Actually, and from what I can read on forum or email list around, ZDZ unfortunately is getting a bad reputation about this. I know of some people at my club that were looking into a ZDZ until they saw me flipping the prop for a whole afternoon without a bang, sweating and cursing. I still believe it is a good engine but I haven't found the 'reliable' way to start it yet.

As I mentioned into another post, the original hole in the choke is too large and there's not enough suction with it to draw the fuel (this hole was 2.5mm on mine). Some people suggested to completely close that hole (which I did) but then, the engine would flood in less than 2 flips of the prop. I re-opened the hole to 1.5mm and from a completely dry situation, it took about 10 flips before seeing some fuel dripping from the carb with tank 6" away.

Some things that might help:
- check the timing of the ignition (Vlach website)
- flip the prop slowly over the top.
- make the low end richer for the first start, then back to normal where you have a good transition. Following starts in the day are generally easier.

Eagle Flyer

My Feedback: (84)

I soldered the hole almost completely shut in the choke plate then made sure it was seating properly in the throttle bore. Started with a dry fuel line, half tank fuel, and it sucked fuel to the carb as fast as could be expected. It's a taildragger so I have the tail raised as I choke ,with the throttle wide open and ignition off, to be sure the fuel is actually going into the engine. Turn on the ignition and flip a couple times and it pops immeidiately, turn off choke, flip a few times and it starts right up. Warmed up it starts very easily. Anybody else having problems starting these engines I would suggest Closing the hole in the choke plate to about 1mm or 1/16". Then look thru throttle bore and adjust choke plate so it seats tightly all the way around. Little to no light shineing thru. If unable to achieve a good seal around the choke plate it might be becessary to completely close the hole to obtain enough draw to get the fuel to pull into the engine. If you do this then check to see if it floods too easily when choking a cold engine. Be sure to use locktite on the plate retaining screw. Engine runs great now. Accellerates as fast as the servo moves. Thanks for your help Boca ben.