1972 Tec H35 carb options.

[Sprocket86]

Unfortunately the original carb on my 1972 DMP Scamper with the TEC H35 engine is shot. Someone over tightened the LS needle and broke off the metering tip of the needle in the carb body :censure:

I hear no check ball rattle when I shake the carb body and the throttle shaft has a good amount of slop. Time for a replacement carburetor.

I attempted to mount my O.E.M Tec HS50 carb that I know is a good running carb but this little H35 didn't seem to like it.

I cannot get it to idle with the choke off. LS needle is at 1 turn and HS needle is at 1.25 turns out. It almost seems like it's running out of fuel in the carb bowl.

Will these smaller HP engines run with a larger HP carb mounted to them? Both carbs have the same throttle bore but the HS50 carb does have a larger venturi.

How critical is it to run the fuel line through the fan shroud behind the flywheel for proper gravity feed fuel flow?

Here is a pic of the engine I'm referring to.

 

[Sprocket86]

Progress has been made and I'll be honest, I'm kinda kicking myself here. Turns out that I had set the low speed needle to rich and it was simply just loading up and would stall.

Here I'm thinking the low speed circuit is not metering or the carb is being starved for fuel. Carb liked being set at just over 1/2 turn out from closed on the LS needle.

 

[Mariah]

Having a gas line droop down like that will cause you problems, if water condensation lays at the bottom of the hose it will stop the gas from flowing to the carb. Water has the weight to do that.

 

[Sprocket86]

I've since re routed my fuel line through the fan shroud behind the flywheel. I was happy to see that the little steel fuel line retaining clip was still present as they are usually missing.