# WYA Carburetor



## bob1190 (Apr 18, 2010)

Anybody know how to remove silicon from Idle adjust needle on a WYA barrel carb?


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## bob1190 (Apr 18, 2010)

Wasn't silicone. was plastic plug. Now to the problem. EbZ7150 Red Max backpack blower. Vacuum and pressure hold real good. Fuel filter new. Fuel line new. Put a kit in cab, after ultrasonically cleaned.Idles fine. will accelerate ok then loses power quickly. gas comes out of carb at air cleaner tube. Adjusted idle needle per Walbro. Turn needle in till in runs fast, back it out to rich optimum speed. Then when i throttle it down it dies. Did NOT replace spark plug. What's missing?


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## Sir Thomas (Dec 7, 2013)

bob1190 said:


> Wasn't silicone. was plastic plug. Now to the problem. EbZ7150 Red Max backpack blower. Vacuum and pressure hold real good. Fuel filter new. Fuel line new. Put a kit in cab, after ultrasonically cleaned.Idles fine. will accelerate ok then loses power quickly. gas comes out of carb at air cleaner tube. Adjusted idle needle per Walbro. Turn needle in till in runs fast, back it out to rich optimum speed. Then when i throttle it down it dies. Did NOT replace spark plug. What's missing?


When you say Carb kit, did you replace the meterring valve? Another words how far down did you break the carb. Sometime fuel coming out of the carb throat indicates that too much fuel is being pumped. When you take the spark plug out is it soaking wet? When you take the Carb apart again, check the metering diaphram and the lever. Does the diaphram have a tall tet (little button on the part of the diaphram that contacts the metering lever) or a real small one, almost smooth.

See Metering Lever Setting

WYA? I see kits for WYA on eBay but nothing on Walbro's Website. I have a Walbro (and Zama) metering Gauge and I don't see a WYA so I can't tell you where the metering meter should be set but is sounds to me that the lever is too high.


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## bob1190 (Apr 18, 2010)

I have replaced metering diaphram and gasket, pump diaphram and gasket, metering lever and pin and needle. Cleaned in a very good ultrasonic cleaner. Exhaust port is clean. No scoring on piston. Compression is 130psi. Spark is constant (not a coil issue).


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## Sir Thomas (Dec 7, 2013)

What size is the tet (the little button on the diaphram)? If it is large, maybe a little less than a 16th of an inch, then the metering lever should be below the surface of the edge. See this WYA guide


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## bob1190 (Apr 18, 2010)

Metering needle adjusted with walbro gage. Metering diaphragm installed button down. I am very familiar with carb set-up and proper orientation of parts. I am not being sarcastic, just informing. I definitenately appreciate input. I might be diagnosing the wrong system. 

Doing the same thing over again and again is a sign of insanity. I beginning to think i"m there.


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## Sir Thomas (Dec 7, 2013)

I wasn't trying to say you don't know what you are doing. Sometimes I have to remind myself because I overlook something.
Does this carb have one or two mixing screws? I know some just has one. 
Fuel coming out of the carb tells me that it's pumping too much. Again I'm not belittling but I, in a rush, put a kit in and discovered that I had the wrong kit. I have two carbs that are identical but the porting is different. The opening for the metering screen on one had a small hole or port in the in the side so it required a different reed valve and gasket than what I put on. When I prime (purge) fuel came out of the carb. When I put the right one in it worked fine. The reed valves and gasket looked identical exept the valve flap was located slightly in a different position and had an extra hole..


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## bob1190 (Apr 18, 2010)

This carb does not have a high and low adjusting screws. It's a barrel type carb. The only adjustment is the one in the throttle assembly, which can be a bugger to get to. I have the tool for getting the plug out ,but it didn't work. I'm leaning toward a new carb, but wanted to exhaust all possibilities . A new carb runs around $87


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## jsouth (Jan 31, 2008)

Check to see if your fuel lines,are not hook up backwards.Also pressure up your gas tank,and vacuum test your tank also.You may have a bad check valve in the gas cap causing tank to pressure up and flood the carb.You may have to replace the gas cap. Hope this helps.

Jerry


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## jsouth (Jan 31, 2008)

BE SURE THAT YOUR GAS TANK IS EMPTY WHEN PRESSURE AND VACUUM TESTING.

Jerry


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## paulr44 (Oct 14, 2008)

Compression at 130 is low. Check intake side of piston skirt for wear - what you're describing, fuel coming out intake, is excessive spitback which is from a worn piston/cylinder. I've worked on scores of the 700x and 71xx series, and haven't seen that symptom so I could be wrong but you're there and I'm here.


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## bob1190 (Apr 18, 2010)

*Update*

I check everything suggested and found nothing looked bad. What did bother me was there was no brass Main jet. I figured it was made that way and I was told it ran real good up to the present. Looking at the ipl, it showed the main jet #57. Ordered jet and installed it, Runs great. I suspect someone took it apart. 

Thank you all for your input!! Always appreciated

Bob


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## Yorpoyntis (Aug 17, 2020)

bob1190 said:


> Anybody know how to remove silicon from Idle adjust needle on a WYA barrel carb?


Use a very small jewlers screw driver heat the end of it with a torch and stick it in hole into plastick. Push down gently and hold for abouut 15 20 seconds the gently unscrew. You now have removed the limiter cap. Your best interest is to replace it when done. The mix screws have been known to back out from vibration. Gl.


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## Bruce M (Oct 31, 2020)

Yorpoyntis said:


> Use a very small jewlers screw driver heat the end of it with a torch and stick it in hole into plastick. Push down gently and hold for abouut 15 20 seconds the gently unscrew. You now have removed the limiter cap. Your best interest is to replace it when done. The mix screws have been known to back out from vibration. Gl.


I have an assortment of dentists discarded tools and use them to remove the plastic plug. I've been working on this for a week and have finally found out the problem. Send $$ to me to find out. Otherwise try removing the carb and putting a gauge on the pulse port. mine was blocked and when i blew it out, voila. hope there was no valve sent into the crankcase but the unit runs. It runs too lean as the engine preignites and pings. have to find out how to enrich the fuel high speed mixture.


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## Bruce M (Oct 31, 2020)

PS. I use Microlon in all my mechanical devices www.microlonproducts.com.


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## Milton Fox Racing (May 27, 2014)

Hey @Bruce M Nice looking Corvette at the micorlon page, but asking for money for your knowledge/expertise is not how we do things here. We share information - like you did about the pulse port. Sharing information about microlon is okay - once - but dont start listing them in every post. That will attract the attention of the advertising staff and a request to register as a vendor before you make more posts. Its all covered in the Terms of Use that everyone agrees to - but never reads!


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