Old 066 going weird on me

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rupedoggy

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Rebuilt a 066 red light. Aftermarket carburetor. Runs great until you put the air filter on then it won't start. Take off the air filter and starts and runs again. First it had a green weinney and I thought that must be it. A new Stihl filter also does the same thing. Has anyone else ever had this problem? Ideas? BTW started the saw and put the new filter on to try while it was running. As soon as the throttle was engaged, it died! Mike
 
Rebuilt a 066 red light. Aftermarket carburetor. Runs great until you put the air filter on then it won't start. Take off the air filter and starts and runs again. First it had a green weinney and I thought that must be it. A new Stihl filter also does the same thing. Has anyone else ever had this problem? Ideas? BTW started the saw and put the new filter on to try while it was running. As soon as the throttle was engaged, it died! Mike
Those Tillotsons that you could buy for about $40 bucks seem to work OK . Not sure if they are even around anymore. Pretty much has to be the carb.

Wow, $80 to$150 on eBay now.
 
Yes I think it is the carb also. Do you think it may be the compensating diaphragm for a dirty air filter gizmo?
No, it really doesn't do much. Just a larger opening to the metering diaphragm than the little hole in previous versions that supposedly changes depending on filter clogging.

But, if the carb you are using has it and the original did not you need to swap the cover over the metering diaphragm, which I am sure you did because there is nowhere for it to go.
 
Rebuilt the original still hard starting and missing etc. The replacement carb came with the correct metering cover.


Does it have the original red light ignition ? They seem to go bad over time.
I'm sure you know it can be retrofitted, but you have to change the flywheel.
 
Inlet lever is not too high? Choke is not binding? Air filter washed in Dawn, rinsed and let dry?
Trying to think of what else could cause the carb to go rich by just installing and air filter.
 
Inlet lever is not too high? Choke is not binding? Air filter washed in Dawn, rinsed and let dry?
Trying to think of what else could cause the carb to go rich by just installing and air filter.

I came across one a few years back that had a nylon mesh filter on it, the owner had washed the filter in acetone to remove some residual dust or staining, the acetone closed off all the air that could pass through the mesh, sort of melted it into a sheet of impenetrable fabric. Changed the filter to a floccked one and no problem afterward.
 
Rebuilt a 066 red light. Aftermarket carburetor. Runs great until you put the air filter on then it won't start. Take off the air filter and starts and runs again. First it had a green weinney and I thought that must be it. A new Stihl filter also does the same thing. Has anyone else ever had this problem? Ideas? BTW started the saw and put the new filter on to try while it was running. As soon as the throttle was engaged, it died! Mike
Is it a nylon mesh filter or floccked, seen the nylon mesh not let air pass through but it had been previously washed in acetone.
 
Good thoughts all. This is a new OEM Stihl oval style filter. Going to dig into the carb next.
Check for metering lever set too low, not allowing the fuel bowl to fill sufficient to transition from idle to wot, enough fuel to idle but not enough to allow to reach WOT, but putting the filter on should have no effect on that. High speed fuel passage clear through to the venturi? Remembering when I had that 266 that would die immediately when throttle was opened, it had a ,floatie in the fuel bowl, it would suck down tight to the jet on throttle up and stall immediately, still had nothing to do with the air filter though.
 
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