Stihl Fuel Filter Question

[mirkaba]

I am having a really wierd problem with my 038. It is broken in now and starts,runs and idles great for the most part. Every 1-2 tanks of gas it starts starving for fuel. I pull the fuel filter and blow it out and it runs great for 1-2 tanks then does it all over. The filter seems to be plugging with something I can't see!!! When I first pull the filter It is very hard to blow through like it is plugged. I am using a clean dry fuel tank 50:1 stihl oil and premium gas. The filter is a new white mesh looking one. Has anyone else had a similar experience? Thanks Bob

 

[Mad Professor]

Are sure it's plugging up and you are not just blowing out the residual fuel at first?

Other things i'd check are: 1) the tank vent line and it's two grub screws, 2) Underneath the metal cover of the diaphragm that pumps the fuel on the carb. I've had sawdust work it's way in through the vent hole and once there is enough the diaphragm can't pump anymore., 3) Small crack you can't see in the fuel line.

 

[mirkaba]

Thanks........The carb is freshly cleaned/rebuilt. New fuel line and vent (button type) came with the new fuel tank assembly. The impulse line and boot are also new. Very frustrating. I did not replace the seals or crankcase gasket when I rebuilt it. Doesn't act like a vacuum leak though. I think I'll tear the carb apart again. Its so dam intermitant arrrggg.................Bob