Walbro throttle plate numbers


Well-Known Member
Was going to try some carb swapping on a GP61 to see if I can get rid of the midrange burble, even though the sparkplug is a dark grey.Some say its the muffler,others say it does it until the engine is broken in?

But what do the numbers mean on the throttle plate.
I have two HDA Carbs.One is 45a off a BME58 with the number of 34-215 on the throttle plate.The other is a 246 that came on the GP61 with the number 34-100.I thought they might be the bore and jet size of the carb?