440 with carb issues, how much for a carb?

[evo]

I just acquired a 440, it was last used about a month ago or so. I drained the fuel, and I put new ethanol free gas in (same as all my other saws). It ran great, so I bought it from my friend. The condition of the saw is practically new, cylinder looks awesome, looks like the chain has never been thrown.

I took it to a job, where I had to cut some brush to get to the tree. It ran great, for about 5 minutes. I got to the tree, and it would start but soon as I hit the throttle it would burble out and die. I'd have to choke it to get it to restart. I've tried to adjusting the carb, with some improvement, but not I can't get it operational. It nearly gets there but the limiter cap feels like it's preventing it from getting to where it needs to be.

It probably needs new diaphragms, or a new carb. My local shop says they can get a carb for $100 if needed plus shop time. This seems a little steep for the parts, I'm finding Zama carbs for $30 or so online. I'm confident that I can slap a new carb in, is the local shop asking too much? Anybody else remember what they paid to have a carb replaced?

 

[GrahamS]

I would save the money and just do it yourself, carb rebuilds are pretty strait forward, and its really good knowledge to have if your running saws all the time. Have you taken apart and looked at the old carb yet? Most likely you would just need a repair kit for whatever zama carb you have(there will be a number stamped on the body somewhere like S126A...ect). Check the condition of the metering diaphragm/seals, check the needle(watch out for the little spring it will fly away), clean any gunk off the screen and replace as necessary. I like to take the adjustment screws out as well, soak everything down in carb cleaner and let it dry off. I avoid compressed air for the most part. If your having problems with the limiter caps, you could take them off, probably not supposed to but if your diligent on your saw tuning you should be ok, I have taken them off of most of the carbs I rebuild. Remember to put the adjustment screws back to stock settings which are usually one full turn out from fully seated for stihl saws-then make adjustments from there. While your at it check the spark arrester screen and see if its all gunked up with carbon, sometimes that will cause the saw to run like crap as well. Hopefully that will get you started.

 

[evo]

Thanks for the advise.. I haven't taken anything apart yet, other than cylinder inspection to see if I want the saw. I'm not opposed to working on it myself other than finding the time. I'm waiting on the shop manual from the library before I start to tackle dissecting the saw. I'm great at taking things apart, but putting them back together is another story (tree guy geesh...)