OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Chainsaws and Concrete Cutters Petrol Chainsaws and Concrete Cutters Zenoah Chainsaw Won't Start. Help!

grumpy,
I must admit that this carby has me a little puzzled. I have attached some images for your advice and comment. I appreciate that the exploded view covera the whole WT series, as my carby is much simpler and has no manual priming gear. The carby image shows the main block and the choke and throttle shaft assemblies only. For interest I have inserted a copper wire through the power needle seat as far as it will go. (Wire diameter is 0.67 mm.) You will see that it passes across the main jet fuel pick up hole to the right of the main jet check valve/block?. It appears to enter a side opening in the base of the main jet block, which seems to be solidly blocked.
Compressed air and carby cleaner fluid will not pass through the main jet when fed from either the power needle passage or the base of the block which can be seen in the image. The base of the main jet block bears the number 34, and has a small hole at its centre. An even smaller diam. hole is centered on this one.
Looking at the Walbro manual images which illustrate operation at idle and full throttle, a check valve is shown preventing main jet fuel flow at idle. As a check vale is usually operated by pressure difference across the valve, can you tell where such a unit would be sited in this carby - maybe the valve is stuck shut? As the fuel appears to enter the main jet block from the side and not the bottom, can you suggest a means of cleaning it while it is pressed in place in the carby block?
Thanks in advance,
mustang