[Yakin]

I changed the carb on my ZDZ 40 from a Bing to a walboro WT 201 this year and it runs very well. It ran ok with the Bing but required a starter especially when hot. Now it starts by hand easily hot or cold. I modified the carb block myself, wasn't to difficult so you shouldn't have to send it in.

[mightyman6269]

What was involved in the modification? If you don't mind sharing that is.

[Yakin]

Don't mind at all, to make the Walbro work on my engine all I had to do was drill a new hole for the pulse hole in the mounting block and gaskets. Just make sure it aligns with the machined groove in the rotary valve cover that feeds the pulse signal from the crankcase, I am going to take my motor off to make a better set up for the choke, let me know if you would like some pics. The throttle arm and choke are in different locations so you will ahve to rework your linkages a bit but nothing major.

[mightyman6269]

I would love to see some pics, that would be very helpful.
Thanks

[Yakin]

I should be able to get some pics taken this weekend and sent to you.

[mightyman6269]

Thanks

[YellowBird]

Hi,

I too am having troubles with my old BING carb. I'd be very interested to see your mod pics too. I really don't want to send this engine back to RCShowcase at the moment (too long to wait, flying season is too short).

Cheers,

Jamie

[mightyman6269]

I don't have the info yet on the mod. What kinds of problems are you having with yours??

[YellowBird]

I have an older ZDZ 40 RV-L. I had it in for service with RCShowcase last year. It had a new front bearing, ring, cylinder cleaning, spark plug and a mod to the BING carb (extra screw added in corner). I have been running the engine on Pennzoil Air cooled oil RCShowcase sent me back mixed at 32:1. It was running an 18-12 prop. I've put two gallons through it and have switched the prop to a Meijlik 20x10 CF. I have not changed oil mixture yet. I was about to when this trouble started.

It was running fine all last year and the beginning of this year. However
recently it hasn't been making the power it once did. The ignition is
adjusted to 5mm from TDC. The ignition batts are good and all that. It seems to be having a problem transitioning to the high speed needle. It quits past half throttle. The needles are about 1.5 turns out each. The low speed runs fine, but as stated the high speed seems to be the problem. I've taken the BING carb off once and removed the plates to have a look for inside. I cleaned it as best I could by blowing through the ports, removing the needles, etc. After reassembling it, I got it to run well only once. I thought I had fixed it, but after replacing the cowl, the problems started again. I am thinking the carb needs parts. I have seen here and on RCU that replacing the BING carb with a Walbro WT201 is a possibility. The BING has never had a rebuild. It's about 5 years old. I also pulled the plug out and it was quite black. Blacker than I would have expected. I replaced it with a Champion RDJ8J (no NGK available locally) thinking that may have been a problem, but no change.

I sent this info off to RCShowcase and got a response from Mike Dooley regarding the conversion. He said the backplate needs to be machined to accept the WT201. I presume this is just the pressure pulse hole relocation. I was intending to order the carb from them and make the mod myself, rather than lose a month of the flying season and probably $200 getting it fixed up by RCShowcase at the present time.

I may just set the plane aside, buy a new engine with a Walbro carb over the winter. Maybe move up to a 50cc. I'm starting to tire of fussing with this thing.

Is this similar to your issue, mightyman6269?

Jamie

[mightyman6269]

It seems, with my engine (my first gas engine) that the engine leans out no matter what settings are put to the high and low. I got so tired of working on this engine and the numerous dead sticks that I have set it aside and bought a new one. I might pack it up and send it to RC Show case and let them at it. Just worried that it will end up costing to much.