just converted a ryobi, it idles perfectly but will die the second you advance the throttle, tried adjusting both low and high needles but nothing works...does not have a walbro, i think its a zyla or something...
any help greatly appreciated..

More than likly the carb is a Zama. Much like a Walbro but from China. They work Ok. Have you had the carb apart? If you haven't you should do so and blow out the all the little passages. Then put it back together (as long as all looks well) and try it again. You can rough set both needles at 1 1/2 to 2 turns and work from there. High speed first. All this is assuming that the ignition is Ok.............Bob

Yep, very likely a gumed up carb

thanks, i'll give it a try....

Make sure the fuel pump diaphram is soft and flexible. if it stiffens up it will flex enough at idle, but not enough to pump enough fuel for high speed. Saw shop should have a kit.

i took the zama carb apart....looks very clean, i blew it all out with an aircompressor, reassembled, and the same thing happens, so i put on a different carb, and the same thing happens, good low idle but nothing else, then it dawned on me that the fuel may be to rich, which i think it is, i had used the gas that the trimmer manual calls for, 4 oz of oil to 1 gallon of gas, i haven't tried it yet, but, does that seem like a logical reason for the problem? if it worked as a trimmer why won't it run now..hhhmmm...

Hmmm, that is a puzzle. Your gas/oil mix should be OK. Make sure that there is no problem with the little crankcase pressure pulse passage to the carb. Watch for sealant or a gasket out of place blocking the passage, yet be sure the passage is sealed from leakage to the carb bore or outside.

Also check for air leaks. These engines are very sensitive to any air leak at all in the fuel system. If your tubing connections aren't completely airtight, it won't pump fuel. I've had problems with fuel tubing being tight at first, and then loosening up and leaking air after being exposed to gasoline for a while. (Especially if the gas has ANY alcohol in it.) I usually use some sort of tie wrap to secure my fuel line fittings. A "wire tie" off a loaf of bread will work in a pinch.

Hope this helps,
AV8TOR

Another thing that you might check is, if this carb has two lines from the tank to the carb you may have them on the wrong part of the carb. Try reversing them...........Bob

Check out this post. It has a wealth of information on carbs. It's a real testimony to what people can do to help others. I C&Pasted to a Word document for my future reference. Thanks RCIGN, tgk, and the others that made had great diagnostic ideas. The meat of this post should qualify for a sticky post!

http://www.rcuniverse.com/forum/what...1336526/tm.htm