power-RCU

Howdy, can anyone tell me the model number on the bme 44 carb.Second question does anyone understand the numbering system on walbro carbs? How do you know how big you can go? The G45 and G62 Zenoahs use the same carb these carbs have a huge bore! Some engines get by with a smaller bore. There are so many WT, HDA,WA,WTA,And a ton of numbers. If anyone has tech specs on these carbs please drop me a message. Thanks for your time!

POWER

Antique

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Walbro makes many different models..Each manufacturer has the carb tailored to his individual specs..The letters refer to the "family" of the carb, and the number is for the manufacturer..In general the WT 76A is used by most of the Sachs based engines up to 3.2 cubic inches..The SDC 80 is used on most sizes from there to the 5.8..Zenoah uses the HDA 48D for the 45 and the 62..The G38 uses the WTA6 on the older models and the WT338 on the newer ones..Quadras and US engines use the WA series..I did a test a while back on the US 41 using three different size carbs, from about 3/8 to 9/16 bore size..There was less than 200 rpm difference from the small to the large..Walbro will calibrate a carb to the manufacturer's specs if required, but most of the airplane engine makers use whatever size was on the original chainsaw..There is a cross reference in the Walbro catalog that will tell which engine the carb was originially made for..I have the book....
If you want the spec on a specific model let me know..
The BME44 probably uses the WT76A.....
The number cast into the venturi on the choke side is the venturi size in 64ths...
An engine will not pass any more fuel than the porting was designed for, so a larger usually is no help..The engineers know more about this than we do..
A manufacturer would not put a carb on his engine that would be too small, as they all cost about the same, mostlt between 40.00 and $65.00...................