Walbro carb question
 

I have a stihl 44cc engine that sometimes wont pump. not sure why. even with my finger in the bore it still wont pump. the next day it will....??? Go figure... I tried replacing it with the carb from my Mac 46 engine that was recently removed from the saw which ran great but has not been run since removed. When i put it on the stihl it just shuts off above 1/2 throttle. The mac had an external primer bulb that has a nipple on the carb next to the needle screws. Should it be blocked off or open? Maybe i should just get a new carb? Thanks for any words of wisdom.

RE: Walbro carb question
 

Sounds like a piece of dirt messing up the one way check valves or a small leak in the diaphram. Not sure! Capt,n

RE: Walbro carb question
 

Walbro Manuals

Go to Pe' Reivers (MVVS dealer) site and in the top sticky there are links to two Walbro Service Manual files. They are rather extensive for the "WB" series. But I think most of this can be transposed for our use on the WA's & WT's?

http://prme.nl/forum/viewforum.php?f...667cec7286afc8

This was posted over in gas engines a short while ago

I thought we all needed to know this?

Jim

RE: Walbro carb question
 

Thanks....thats some good info.

RE: Walbro carb question
 

Take the diaphram out and inspect it. I had a engine I could not keep in tune. When I held the diaphrame up to the sunlight I noticed a very tiny crack in it. Thats when you need a new one. If it has more than one rubber part that does not look good... replace all. Capt,n P.S. when I store a carb...I run silicone spray in it with red tube. Works Great!

RE: Walbro carb question
 

I gave up and bought a new Zama carb from Brillelli ($6 + shipping) and it works great!!

RE: Walbro carb question
 

What size throat on the Zama? Thanks Capt,n

RE: Walbro carb question
 

I think it's a 12.5. Venturi size isn't everything. Sometimes you need to go with a smaller venturi size to get good transition. I didn't lose any top end rpm when I switched to a smaller venturi, but i sure gained alot of transition and much better idle.