MF202 carburetor issues

[ImHim808]

I have a Massey MF202 backhoe, it has a Marvel TSX834 carb, but the manual says it should have a TSX683. It starts and idles fine, but at full throttle I am unable to get it to run strong, it can bearly drive around the yard or operate the backhoe or loader without stalling out, I need to get the RPM"s up. I"ve checked all the basics, clear fuel flow, linkage is opening all the way, all jets are clean and clear, tried all adjustments with timing, carb, and governor. It has a completly rebuild engine, clutch, distributor, so everything is pointing to the carb, I did have to machine a new venturi, it fits tight. Before I spend money to buy a TSX683, Does anyone know if the TSX834 would work for the MF202? should I try a larger jet? where could I get larger jets? where could I find more info about these old Marvel carbs? Any help out there, Thanks Bob

 

[TODD 24]

My 44 Special acted the same way, would start and idle just fine but barely had enough power to pull itself. A new set of metal-core plug wires did the trick; engine cranked out full power and ran perfectly.

 

[ImHim808]

I have new wires on it, they were just a universal (cut to fit) kit that I got from a local tractor supply store. Is there a way to measure the output of the spark (like connect to a voltage meter)? or just by holding the wire on a ground and viewing the intensity and color of the spark?