Got a new carb from wacker, and wondering which tube is the proper one to hook up to clunk.
No matter what I do I cant seem to get it to draw fuel. I got it to run one short burst by holding tank up above carb.
Have done the usual , cleaned filter, new lines, fresh fuel, new plug, etc. . Homie 30

Aloha, Les

What about your impulse from the crankcase to the carb? Do you have it aligned? The carb will not pump at all if the air impulse hole is blocked.

Enjoy,

Jim

Yep, I checked that out and found the carb base gasket to be some what soft, but I dont think its enough to block the passage/port.
Will take a closer look tomorrow, and maybe make a new gasket. Now I am wondering how fuel is regulated, pressure and/or flow.
Maybe I will give wacker a call. Or try another carb. etc. etc.
Thanks for your help, I am sure its some simple little thing or oversight.
Aloha ,Les

Les,

The carb has a pump on one side and the fuel goes to the other side to a demand regulator that will not let any fuel past it unless there is a slight suction by the engine. You may have the fuel line on the wrong one if it has two fuel inlets. One is a return and should be plugged.

Jim

Les, block off the one by the needles. Oh, It has a plastic type pump in it so the first time there run it takes a bit to draw fuel because there stiffer, I took the pump side off and primed it directly and re-assembled it, then it took right off. Piper

Sounds like no crank case pressure.Is there a tube connected to the engine from the carb?

Thanks , Mike, Jim, and Scott, . Have made note of all your comments and will try again today. Looked at the walbro site also, and they mention a metering lever adjustment. I also bought a couple of kits just in case.
Aloha, Les

http://www.shark-racing.com/Ingles/T...Tecnicaing.htm About half way down on this page are walbro diagrams of operation. Plus there's adjusting methods from Warehouse Hobbies and a link to the Walbro site.

Enjoy,

Jim

Thanks Jim , I got it to run but only at idle. As soon as I give a little throttle it starts to die out.
Time for lunch ( Pizza Ha ! )
Mahalo, Les

Gonna watch this one closly. I just ordered the WT433 from Wacker a few days ago. This ones for my ryobi. Keep at it.
Edwin

Well the HOMIE runs although somewhat erratic. Found another carb and she took off like a scalded cat. I think might be the coil breaking down at high rpm. Might be more than one issue involved. At least some progress. Yea!! Maybe an ign system? Hmmmmm
Anyone have any experience with setting the lever on the needle & seat. I see on walbro site they have a special tool. Wouldn,t you
know it?
Thanks every one,
Aloha , Les

Edwin , I bought the 433 and two kits but still had to make a base gasket. Still not sure about this carb. She just wont take any throttle
increase.
Aloha Les

I just got my stock ryobi carb working this evening. About 6 months ago I converted it using a jag setup and was getting 6700rpm with a zinger 18x8. Which is about right. After sitting for the 6 months I installed it on the plane I built for it and it ran like crap. Would only get 5000rpm and had to lean out both needles a lot which wasnt right. That was using 6 month old gas. I made up some fresh gas and used klotz oil and got nothing, wouldnt start. I put in a carb kit, same thing. So I disassemble the carb and cleaned it in a sonic bath for 45min using water and dawn dish soap. During assembly, I adjusted the float valve also. Runs like a top now. Got back to 6700rpm. This is my baseline. The stock carb also has the primer tube on it. I blocked that off with some med tygon with a fuel dot and zip tied it. I had some surging at one point and I think it was leaking a little there. I also found a small cut at my fill line. Basically, a bunch of little things added up to make it run poorly. Tomarrow is the maiden flight of my highly modified Bandito Grande. Had to move the firewall back 3 1/4" to get it to balance with no additional led. Total weight is 13 lbs 14 1/2 ozs.
Edwin

Less,

It sounds like yours is lean. Mine was doing something a little like that but would only rev up to about 1/4 throttle then die. Both my needle valves were less than a full turn out, just to get an idle. But not much more than that. I read on the walbro site that if you have to adjust the needle valves too far from the starting point (1 1/2 turns) then the float valve needed adjusting. That is what did the trick after I put in the carb kit. When I put in the new carb kit the symptoms all changed and I was starting from scratch again. I basically eye balled the adjustment. Just make sure that when you push down on the lever that you get a little movement on the float valve. Made all the difference on mine. Now both needle valves are like they should be. Its probable that they didnt run in the carb after assembly and might have missed adjusting the valve. Just a guess!
Edwin

Got a letter from Peter at Wacker today saying he would replace carb if I determine it to be defective. Its nice to know that people are looking out for us customers. Thanks Peter. I will be sure to let everyone know the outcome of my findings . I am looking for a different coil to try at present. Also a fresh batch of fuel. Once again thanks to all who shared in my experience including Peter at Wacker Engines.
Aloha , Les

I just ran across your carb thread. A friend of mine just got 2 carbs from wacker and neither one draws fuel. He has had 5 other carbs on the engine and it runs fine. What did you finally do to make it draw? It will run on prime shot into carb but the carb will not draw. I looked at it and we can't see what is wrong.
Any help would be appreciated. thanks
Jerry

Jerry, the carbs have a stiffer plastic type of pump rather that the rubber one. I took the pump plate off and primed the carbs innards and put it back together and it took right off. I guess these carbs were used on a motor that had a primer bulb or something that made it easier to start the first time. Anyway, once i got the motor running on the carb its ran fine ever since.

Thanks for the heads up. I received mine last wed. If I have to, I can change out the diaphram out with one of my others. I want to do the maiden first and get some flight experience with this setup before I put the other carb on.
Edwin

Just bought the WT 433 and installed it on a Ryobi 31cc. The engine ran perfect right from the start. The line from the tank go's to the large diameter brass pick-up, the small brass pick-up is sealed off,( I use a piece of fuel line with a small bolt screwed in the end). This big bore carb pumps a lot of fuel for a 31cc engine. I run with the high speed needle almost closed and low speed 2 1/4 turns out. Fantastic low idle and instant exceleration. With the Jag Engines Muffler and the Wacker Engines Carb, this engine now sounds like a mean chainsaw engine rather then the wimpy weed-eater engine it use to be. The engine is not lean at this setting and after idling for a long period will put out a puff of smoke at exceleration. The one thing I did note is that if you put any part of the fuel-line above the carb ,creating a hill for the fuel to climb it will not draw. Keep your fuel-line a relatively straight line from tank to carb and you will have no problems. I am drawing more fuel than I need and am completely satisfied with this carb and will buy again. -Ron

Thanks for the link. Very informative! (see post 8)

I've been experiencing all the same symptoms as everyone here. The only thing I havn't tried is to plug the second line. It is strange how the response is so diferent when the 2nd line is open compared to when it is connected to the tank vent line. Then, throw in the metering lever, and you have a whole new list of setups. Who would have known that such a little carb could cause so much frustration for so many!
I found that it takes a bit of monkeying with the metering lever to get the right amount of fuel to flow so you can properly adjust the needles.
I did have a look at my spark plug after I killed the engine at WOT to make sure it wasn't too lean. Lots of trial and error.

play with the metering lever and needle. i thnk the walbro sites say it should be perfectly flush with the area around the needle. once you tear it apart you will see what i mean. i didnt use any special tool just a small flathead screwdriver to pry it up a bit and that opened it up to draw more fuel and fix my problem on a stubborn walbro.

my bet is that will fix it. i bet your ign system is fine. make sure the gap is set to a business card thickness and play with the carb ;-)

Tried carb off the old weedwacker ( Zama ) and everything is great. Sent carb back to Wacker engines and am waiting for return.
I tried everything under the sun to no avail. Now that I know engine runs I can carry on. Halleluja!

Aloha , Les

Hey Fellows.
You got to watch what your doing when prying up a needle lever .I 've done this several times on a weedeaters that someone brought up to me to fix but it never worked with me.After prying up it starts flooding and leaking fuel so i alwayse ended up buying a rebuilt kit and sticking it in. Just be careful when you prying.Good Luck
Mitty

Well, I messed with the metering lever, but only a bit at a time. I kept at it until I got the needles in a good range like 1.5 turns out. I have not received my muffler from Wackerengines yet and the venturi is only 7.94 mm (wt-160B) on the carb I have. I am spinning a MA 16-8 at 7600 rpm. I wonder if the new exhaust will improve it much? Cause I'm a greedy little bugger when it comes to RPM. I like to have more rather than less than enough.
What would you estimate the increase in rpm with the big bore carb?
Thanks