Honda GX50 Adjustable Carb?

[AccessDubious]

Hello,
I'm a serious cyclist, but have never played with motor assisted bikes before. I recently purchased a Staton GX50 friction drive kit with a 1 1/8" roller for multi-hundred mile trips through the mountainous western states. The owners manual states that the carburetor needs to be modified for high altitude use, but once that is done, the engine may overheat if used at low altitude. Currently I don't expect to be going lower than 3,000 feet, and passes peak at over 10,000. From my research I believe I would need to go one jet smaller (from a #44 jet to a #43). However, I am not sure if I would need to make any other adjustments to the carburetor, and short of purchasing the $40 shop manual, I am unable to find that information anywhere. Does anyone know the process for setting up the GX50 carburetor for high altitude use? I have never worked on a carburetor before, but I can learn.

Or, would it be a good idea to get an adjustable carburetor instead? If so, what carb would fit/work? I can't find that information anywhere either.

Thank you much for any help,
AccessDubious

 

[DieselTech]

Hello,
I'm a serious cyclist, but have never played with motor assisted bikes before. I recently purchased a Staton GX50 friction drive kit with a 1" roller for multi-hundred mile trips through the mountainous western states. The owners manual states that the carburetor needs to be modified for high altitude use, but once that is done, the engine may overheat if used at low altitude. Currently I don't expect to be going lower than 3,000 feet, and passes peak at over 10,000. From my research I believe I would need to go one jet smaller (from a #44 jet to a #43). However, I am not sure if I would need to make any other adjustments to the carburetor, and short of purchasing the $40 shop manual, I am unable to find that information anywhere. Does anyone know the process for setting up the GX50 carburetor for high altitude use? I have never worked on a carburetor before, but I can learn.

Or, would it be a good idea to get an adjustable carburetor instead? If so, what carb would fit/work? I can't find that information anywhere either.

Thank you much for any help,
AccessDubious

Can you get us a good picture of the carburetor, possibly multi pics of top bottom & sides. Will help us figure out exactly what you are working with. Possibly making it easier to help you tune it.

 

[AccessDubious]

Hopefully this helps. Not sure if that tiny phillips head screw is for adjustment or just a fastener.
Also, I realized I said that I got a 1" roller. It's a 1 1/8".

 

[DieselTech]

Lol you didnt have to disassemble it! On the cable side of carburetor, is there a screw in the center of the throttle arm, looking from the top.

 

[darwin]

DT?, in pic 5 is that a brass plug covering a mixture screw?

 

[DieselTech]

DT?, in pic 5 is that a brass plug covering a mixture screw?

Yeah I was wondering that myself, it very well could be a mixture screw under brass welch plug.

 

[Chainlube]

DT?, in pic 5 is that a brass plug covering a mixture screw?

I have a similar carb here and it has a mixture screw at that location.

 

[AccessDubious]

Lol you didnt have to disassemble it! On the cable side of carburetor, is there a screw in the center of the throttle arm, looking from the top.

It's good, I already had it disassembled.

There appears to be a brass pin with a single flat at the bottom of that brass cup.

 

[DieselTech]

It's good, I already had it disassembled.

There appears to be a brass pin with a single flat at the bottom of that brass cup.

That D shape pin is a carb adjustment screw, & I believe other adjustment screw is under brass plug in pic#5. Drill a 1/32" hole thru plug & pop it out with a O-ring pick.

 

[AccessDubious]

Here's what appears to be on the other side of that brass plug.