j301

My Feedback: (12)

Thanks to all those who helped me I.D. this motor, now that I know what it is, I need some help getting it running. (original post here: http://www.rcuniverse.com/forum/m_11...m.htm#11138067)
In a nutshell, webra bully 35, now with a JTEC pitts muffler, original carb=HDA 48 (21-245), new carb =WT 610, CH ignition (older unit) The best I could get out of the motor so far is 6500 on a 18/10, but to get it to transition I need to fatten up the high end which drops it to 6100, this is with the original HDA 48. I believe the high and low needles are missing either 1 or 2 washers and the o-rings, but I cannot find these to replace them. I put the WT610 on hoping to solve the transition problem as it is pumped. Now the engine will only run through its prime and die. I was able at one point to get it to idle(ish) but only with it choked. I have rebuilt and cleaned the carb, and also tried raising the needle lever to almost flush with the case. It has good compression and spark (*also replaced plug and both gaskets on carb/mount). I dont know whats left to try, and am fairly new, but not in the dark, to gassers. It seems to be an issue with the idle and high circuit as the start side seems to do what its supposed to. Any help at this point with either a source for the illusive needle kit for the 48 or how to cure the 610 would be greatly appreciated,
Jim

BOB MOORE

I have had two Webra's . Always 18/8 prop.Timing 5degrees btc @ idel. Carburator WT 76A. Wore the first one out after ten years of flying. Have you checked the screen. My first had more power then G-38
My friend and I had planes alike same weight and I could run circles around him. You can buy carburator fom V.E. Peterson. He has all the ones for all engines that or made @ great price
B&B Muffeler

w8ye

My Feedback: (16)

Repair kit for HDA carb

http://www.davesmotors.com/s.nl/c.88...t.A/id.8055/.f

w8ye

My Feedback: (16)

The carb for a DLE 55 is the same size as a Walbro WT-76A

w8ye

My Feedback: (16)

http://tewarehouse.com/WT-76-1

BOB MOORE

www.vepetersen.com is cheeper,

w8ye

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I have to pay sales tax on Peterson stuff

j301

My Feedback: (12)

Bob, thanks for the info. From all I've read the other Bully owners were bench marking their rpm #'s with an 18/10 on average of 7500 to 8k which makes me believe I still have an issue, though Im sure it would spin an 18/8 close to that. I checked the timing and its at about 30deg btc. From what I understand, isnt this about right for an electronic ignition unit? I have my Zenoah's set at about 28btc.
I also found another person who's bully came with the same HDA 21-245 as mine has, so Im not sure when the production changed. After some research I decided to go with the WT 610 as it was one of the carbs that took the place of the WT 540, which was the popular choice to upgrade 3W35's and G38's to. I did change the screen on both carbs, I used the full rebuild kits on both (though the 610 was new), not just the diaphragms and gaskets. I also assaulted them pretty good with cab cleaner and an air compressor. Someone on my original post also mentioned the case might have an air leak where the two halves join, I need to check that. Did yours have this issue?

Also want to say thanks to w8ye for the info. The parts I need for the original carb no one seems to sell. I can get the idle and high speed needles, but I cant get the washers and o-rings which are really the parts I need. Since Ive already spent as much money on the carbs/kits and exhaust as the motor originally cost me, I am hesitant to spend another $50 or more for another carb. Any idea why the 610 will only run through its prime then die? Its getting to the point where if I cant get what I got to work, it may end up a really cool (and expensive) bookend.

w8ye

My Feedback: (16)

Sounds like the metering valve needle and seat is stuck in your 610

j301

My Feedback: (12)

Thanks for the reply,
I did replace the needle valve lever and needle valve, is this the part you are talking about? How do I un-stick it? Is there something in particular I should look for regarding the needle valve seat?

captinjohn

PM me your phone number and a good time to call. I can help. Capt,n

w8ye

My Feedback: (16)

To get a little more technical, you need to confirm that the needle and seat will pop off and then re-seat.

On the regulator or metering valve side of the carb, the gasket goes against the carb body and the metering valve diaphragm goes on top of the gasket and then the steel cover with the vent hole.

On the pump side of the carb the diaphragm with the little check valve flaps goes against the carb body and the the gasket is on top and then the cover.

Tony Hallo

Sounds like a pump problem, is the pulse port lined up?. While choking, you can draw fuel through the carb without the pump, will die once prime is consumedif thepump isn't working. This occured after you replaced thecarb?

j301

My Feedback: (12)

Thanks Tony, yes this happened with the new carb. It acted the same before and after a rebuild on the carb, and I can switch back to the old carb and she will run, just not to its full potential as I believe the old carb has some different issues. I believe its drawing fuel, but I will double check that by spinning it up with a starter without priming it just to make sure. I think its in the idle circuit side somewhere.

j301

My Feedback: (12)

Just double checked that and its correct, also it seems to draw fuel with choke off, at least there was some movement in the fuel line as I spun the motor. I can rock the inlet needle by hand, and it seem to be free, and the diaphragm is lining up over the lever as well.

If the carb is getting fuel to prime, that would indicate the inlet needle is working and the high side is ok (or at least delivering enough fuel to 'run' on prime) do you think? It seems the likely place for a hangup would be the idle side, of course this is just going by the start and idle diagrams here: http://wem.walbro.com/distributors/s...s/WTseries.pdf
So how do I check those passages?

j301

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PM sent, thanks!

Speedy-Gonzales

My Feedback: (202)

I buy Webra "bully" 35cc engines and rebuild them for the Rcexl ignition modules. I have reworked 5 of them now and bench run everyone of them before offering for sale. The rework consists of throwing the Delorto carb to the side and installing a Walbro WT-540 carb. This is a bolt on replacement but does require relocatioin of the threaded bolt holes that secure the carb to the phenolic insulator ring and paying attention as to not blocking the diaphram pulse port that drives the pump in the WT-540 carb.

I also machine a mounting ring that fits over the strengthening webs on the front of the case where the front bearing race is located. I made my own hub puller for this procedure since the rear hub needs to be removed to install the machined sensor mount. Some have been know to remove the webs to install the sensor mounting ring but I am against it because this weakens the front case and bearing support. The new sensor mounting rig also gives a solid mounting platform for the sensor and keeps your engine in perfect timing at all times. Set it and forget it! I also make a timing ring and press a 1/8' diameter by 3/32" long neodyum magnet in the ring and leave it a sliding fit over the rear hub so I can set the timing with a degree wheel. Once the timing is set with a timing "beeper" at 28 degrees BTDC I then secure the ring into position with a film of JB weld and let cure for 24 hours before running the engine.

I use a Bennet muffler for the Zenoah G-38 and it is a perfect fit. I also make an adaptor plug for the head to accomodate a NGK CMR7H plug that locates the electrode into the combustion chamber at the correct depth for maximum spark and power. My converted "Bully" engines will turn a 3W 19x7 @ 8200 rpm and will idle consistently below 1000 rpm without missing a pop.

I run 92 octane pump gas with Stihl HP Ultra mixed at 40:1 but will soon be testing all my gassers on 100/130 AVGAS.

Here are some pictures of my conversions.

Speedy Gonzales

captinjohn

Speedy G, I found a new in box 35cc Webra at a swap meet. What # of RCEXL ignition do you recomend and where do you find a WT-540 carb? Thanks Capt,n PS What timing..... 28 degrees maybe?

Speedy-Gonzales

My Feedback: (202)

Capt'n

Great to hear from you again!

I should change my RCU name from "Speedy-G" to "Mr Bully"! These are exceptional engines. A bit heavy but the extra weight is worth having a non-Chinese engine that runs like the "energizer bunny".

28 degrees BTDC is correct and the bigger the timing wheel the better. Don't use the itty-bitty one that comes with the beeper.

The Rcexl Timing Beeper is a real gem for getting the timing dead nuts!

You can find the discontinued N.I.P. Walbro WT-540 carb right here in my basement. :>)

The Rcexl unit I use is #1220 with a plug cap that fits a 5/8" hex for the NGK CMR7H plug.

SPEEDY G

captinjohn

I would not have known about how good the Bully35ccengines where...Ralf (RCIGN) also "Antique (same guy) told me about them several years ago. I learned a lot form him. Guys like him, Bill C (CHIGNITIONS) and many others like them is how I learned. I would try to name all the real good Guys that made terrific in depth postings that really helped me and many others in this RC engine Hobby. I cannot even try too name them all...one thing I wouldfeel bad if I left anyone out...that isfrom theHeart. So I wish the very best to them all. Thanks again for giving up you time to help other,s

Speedy-Gonzales

My Feedback: (202)

"RCFLYERDAVEH" bought a reworked Webra "Bully" from me here on RCU and was thrilled with it. He put it in his WWI Eindecker. He said it idled steadily at 900 rpm with excellent transition to WOT with no hesitation. Gobs of power.

CAPT'N....if you need a WT-540 carb just let me know.

I'm in a real good mood tonight. I maidened my Goldwing 50cc Ultimate bipe today and everything was perfect.

Yesterday I took my Dad 70 miles south to Celina,Ohio for a Fly-In with temps at 100+. The heat was intense but the time spent with my Dad was priceless.

It was his 81st birthday.

SPEEDY G

j301

My Feedback: (12)

Hey capt'n, it was good talking with you today, gave me some good ideas. I re-rebuilt that 610, checked everything, soaked it again with carb cleaner in every hole and crack, blew it out and could feel the air exiting all the passages. I was going to try my Rcexl unit on it, but the plug is different and I didn't want to swap boots. But it did give me the idea of trying the carb from my other motor, an NGH 35 which uses a Walbro WT 664A. The motor ran a little better with this carb, got up to about 6750 rpm. I didnt spend a bunch of time to "set it right" as I didnt plan on keeping that carb on the motor anyway, but it does tell me that there is something wrong with the WT610 though. Hopefully I hear back from the person I bought it from, maybe he will offer to swap it out or something.
I also did the bubble test and didnt see any leaks around the case, but at this point I think a new ring from Bowman would be worth it, and if nothing else, just silicon the needles on the stock carb like you mentioned.

Those re-purposed Bullys look nice, but I believe mine was born a gasser, it has the lead off the back from the original ignition and stock carb.

Perhaps in the end, its just this motors time to go, but I will try a couple more things.

Speedy-Gonzales

My Feedback: (202)

All "Bully's" were either/or gas or glow and were all exactly the same just fitted differently. The original factory ignition modules were the main reason the Webra Bully got a bad name as a gasser but the glow version rocked especially with a header and tuned exhaust. Now that the Rcexl ignition modules are on the market the Webra Bully can show it's true potential as a gas/ignition engine IF you can find one to convert.

Don't give up on that Bully! It is made from quality materials and superb German workmanship. I have never seen one that was actually worn out unless it was abused. I am willing to buy it from you or offer my services to get it running right, or I am also willing to just take a look at it if you would be willing to ship it to me for an evaluation.

SPEEDY G.

captinjohn

I guess it would not hurt anything to just remove the cylinder assy and see how the finish on the bore is...also check piston ring condition. Could be it lost it tension or may be partially stuck in ring groove. I have just cleaned the groove and ring...put it right back together and they ran somewhat better. Best is a new Bowman ring. Best Regards Capt,n

Speedy....I sent you a PM

Speedy-Gonzales

My Feedback: (202)

Reply to PM sent.

Speedy G