Help with Walbro Carb ID
 

I have a side carb RCGF 20cc engine. Had been running good for about a year. The wouldn't idle. New carb was sent under warranty. Now out of warranty. A few weeks ago, engine ran good for two flights, then refueled and got ready to fly again and engine would'nt take full throttle. Changed inline filter, checked the internal screen, checked fuel tank and fuel lines. Couldn't find anything obvious. Engine still wouldn't take full throttle. Got worse, now won't draw fuel at all. Can squirt fuel in carb and it will run a second or two and quit. Took carb off and inspected fuel pump membrane and fuel metering diafram. Took out metering needle. Squirted carb cleaner through all the holes and passage ways I could find. Still same problem. Replaced carb with a know good one. Engine runs fine.

This is Chinese copy of a Walbro. Out of warranty. Don't want to purchase another of same. How do I find the Walbro model number of carb that was copied? Carb has about a 10mm venturi, connection for air pulse hose/tube and choke.

RE: Help with Walbro Carb ID
 

Determine what is used on a Zenoah G-26. I can't remember the number but I recently did a swap on a Aerovate 28.

RE: Help with Walbro Carb ID
 

Thanks for the reply. I looked up the carb for the Z26 on Horizon's web site, still don't know the Walbro model number but could order from Horizon. $58. But worth it to avoid the aggravation of the Chinses copies if it will work. Does this use the hose connection for the pulse air? Will the RCGF Insulator block work? Since this is off a 26cc engine, might it be too big and cause a 20cc engine to bog with throttle application?

RE: Help with Walbro Carb ID
 

Your conclusion is right.

Try to use the carb from the 20cc Zenoah

RE: Help with Walbro Carb ID
 

w8ye,

Ok, but does the carb for the Z 20 have the external pulse line connection? Will the RCGF insulator block work? You just can't get much info on the Walbro carbs. Very simply I need a Walbro carb with about 10mm venturi, external pulse connection and a choke. Why is this info so hard to find? Maybe I'm just stupid and don't know where to look.

RE: Help with Walbro Carb ID
 

The WT-811 carb for the Zenoah G-20 is a 11.11mm carb. It has a choke and a high speed check valve

It is on the large size for a 20cc engine.

it doesn't have the external pulse signal nipple for the pump but a boss is on the cover for adding one to the carb.

http://wem.walbro.com/walbro/product...0ZENOAH/REDMAX

RE: Help with Walbro Carb ID
 

The problem with obtaining Walbro info is the fact that Walbro does not make a single carb for model aviation use. They are all for other applications and adapted to our uses.

RE: Help with Walbro Carb ID
 

Any carb can be made for external pulse...Drill a #23 hole in the boss already cast into the rear cover...Push a #128-218 Walbro fuel inlet into the hole...Grind off the brass that's sticking out into the inside of the cover.
Get a fitting from B&B or any small engine shop....Costs about $2...Works for ANY gasser carb on the planet....
128-218 is want almost all carbs use, there are MANY other fittings that work....
ANY Walbro with 28 to 34 cast into the venturi will work, you don't need a $50+ carb...

RE: Help with Walbro Carb ID
 

Thanks for all the information. Upon looking in my spare parts box I found a new WT - 419 Walbro carb that I acquired at a swap meet a couple of years ago as a spare for the one on my SPE 26 (which I never needed) . I looked it up and see its venturi size is listed as 9.53 mm. I see the boss on the cover which I can drill out and I can use the fitting off my old carb. All at a present cost of zero. I'm learning more about these carbs all the time.

RE: Help with Walbro Carb ID
 

You are doing good

RE: Help with Walbro Carb ID
 

I found the hard way,using wrong two cycles oil will cause that problem,my engine will run for one fly,filter will clog out,went back to AMSOIL

RE: Help with Walbro Carb ID
 

Why not just use the pump cover from the old carb on the replacement carb, a bit easier, faster, and less complicatedthan installingthe fitting.

RE: Help with Walbro Carb ID
 

Beat me to it, but not all covers are the same inside...
You going to Joe Nall ?
We'll have the 39lb 222 DLE powered Extra there all week ;)

RE: Help with Walbro Carb ID
 

I wish, it's my goal for next year, Nall or bust!

RE: Help with Walbro Carb ID
 

There are at least 3 different carb cover configurations inside. the reason for all the little extra pieces in the WAT diaphragm kit....

RE: Help with Walbro Carb ID
 

Turns out my old cover is identical so I just switched covers. I'll see if it runs later today.

RE: Help with Walbro Carb ID
 

Sucess. Test ran the engine today. Started ok once I got fuel in the carb. Set the needles. Max 8,150-8,200 rpm with 15-7 three blade Master Airscrew, idle about 1,900 rpm with good transition and good midrange. Runs just as good as the original carb. Ran right side up, held up and upside down, but was too windy for me to fly, 10-20 mph quartering cross wind. Too much for me flying a warbird with retracts.

RE: Help with Walbro Carb ID
 

Here is the engine installation and the plane.

RE: Help with Walbro Carb ID
 

Rbean, which carb did you end up usiing? I am having the same problem with an aerovate 26.......

RE: Help with Walbro Carb ID
 

Now that's the one that got a G-26 carb for a replacemet. Worked great until the front of the engne fell off. Ralph, what's that part nmber?

RE: Help with Walbro Carb ID
 

[quote]Now that's the one that got a G-26 carb for a replacemet. Worked great until the front of the engne fell off. Ralph, what's that part nmber? /quote]




Say what?

RE: Help with Walbro Carb ID
 

WT645 is the G26 airplane engine carb..

RE: Help with Walbro Carb ID
 

Thanks Ralph.

Andrew,

Better not to put your question inside a quote. What do you mean by "Say What?"

Complete info is in the RCGF thread, the makers of the "Aerovate" engines.

RE: Help with Walbro Carb ID
 

Yeah I hit the wrong thing...Say what was about the front of the engine falling off. Does the wt 645 have the external pulse fitting? The aerovate engine does, just trying to figure out what I would need to do...


Appreciate the help very much......

RE: Help with Walbro Carb ID
 

Andrew S:

It's a WT-419 Walbro carb. Have flow it several times now and its doing fine.