Help with Tillotson Carb.

[Lust4saws]

I have a Tillotson model HL on an old McCulloch 250. The saw runs fine, but at full trottle the carb "spits" gas out of the choke end.......So much gas that in less than a minute a couple of table spoons has accumulated in the air box. I have cleaned it and have replaced the needle and seat, and the diaphrams.....and gaskets. I have also replaced the fuel line and filter. What else can I do????? I would try a different carb, but can't find one. Any ideas?
Thanks,
Dave

 

[rupedoggy]

There is nothing wrong with your carburetor. The 250 Mc. is a reed saw. Reed saws are basically open to the crankcase for 360 degrees of the cycle. The reeds close upon pressurization of the crankcase, but because the reeds can only open and close so fast and because of inertia and other things which happen at high RPMs a spitback will occure. This is not neccessarly wrong. As long as your reeds are in good condition and are the correct ones for your saw this spitback is acceptable. Mcculloch has a fuel collector in front of the carburetor just for this reason. It looks like a foam block and is there to catch that extra fuel. Undoubtably yours is missing. Try to secure one of the correct design for your 250 and install it. Check for correct, and correctly functioning, reeds. That should put you back in operation. Mike

 

[Lust4saws]

Thank you very much. The ipl shows no fuel collector for this saw, however. The reed valves are most likely the problem.
Thanks again.
Dave