Just getting this sorted out after changing jug so I could put on a billet intake and 66 speed carb on my 50cc build-
I'd done this once before, and found an IMMEDIATE good perfomance increase- but something got inside and scoured that jug in a few miles- so I put the old one back on and rode it a year or two- you may have seen this bike in my video sound comaprison between the 66 and 50. Someone remarked on youtube that the carburetion socked and I knew they were right- it had run sooo much better with the other jug and a standard 50 carb on a billet.
What I didn't realize was that I could have lately just gotten a new billet that now comes in the same 40 mm spacing the "sleeve carb" did, and still used the older head. Oh well. About the same cost- less work, less risk.
Below is a picture of the old set-up (totally blue) I don't know why that carb never worked very good- they put it right up against the motor- a good idea, but it was a 50cc carb with a different sort of jet I couldn't change.
Anyway- without wanting to push it today- I'm finding the 66 Speed carb and billet REALLY DO give me better performance. Better accelleration, and more revs at top end.
In fact I'm gonna go to a smaller sprocket now too- I have a custom 39 GT alloy sprock bolted to the flip/flop hub, drilled for Disk brake six inner hole pattern,
but I've got another alloy 34 same as on my 66 build- and I think the motor will handle it- One of these:
it really starts to close the performance gap now that the 50 is running better with better carburetion- the 66 Speed carb has a bigger float bowl and a bigger jet and makes a difference. And the Huffy cruiser with 700c wheels build is really lightweight and less noisy. And the NT Speed carb is not nearly as pricey as a "performance" carb.
The carb isn't even very level, but it doesn't seem to be affecting performance