Choice of two carbs 19.5, 17.5

[FurryOnTheInside]

The folks on the forum suggested a few carbs for my builds,,, 19mm to 22 or 23mm...

I like to hear about the pros & cons as well furry...

Always interesting to learn and refresh the memory at my end too...

Don

Those sound large and difficult to set up to run well at all our engine speeds and and throttle positions.
You know the tiny little NT can flow enough to get 8-10k rpm and 40mph out of your bike.
I am hopjng that the second 17.5mm, the kind that is like Chris' 19.5mm but likely more suitable size for my actual usage and pipage, 50mm max pipe diameter, will have the simplicity and the flow rates to go into the forties and beyondddddd

But I will have such a narrow pipe that it wont be drawing intake vapour all the way from the air box..ooh mishiñ

B

You know that the stealthy stock hotdog muffler has enough flow once you've drilled inside it to get your bike going up to 40mph. Might be better to gear it lower though if you prefer decent acceleration p
This stealthy muffler that has been internally damaged to increase flow dynamics is going to be replaced soon I hope. I think I can do most of the cuts to the tubing myself, I will just need the flange making and welding on, and the whole pipe welding together from sections that we know I will cut fairly accurately but I cant get the sections to overlap exactly as you'd want to weld them lapped rather than butted. Thd welder has to want to so it then.. but I will just see.

 

[FNTPuck]

That PHBG 19mm is my favorite carb for the money for most builds. I used it on both my 53mph piston port 69cc chinagirl bike, and with a larger jet on my 65+mph 74cc A35 reed moped engine bike and it performs perfectly on both. Easy to tune while still having fine control over everything if needed.

Its the KTM 50SX carb.

 

[FurryOnTheInside]

That PHBG 19mm is my favorite carb for the money for most builds. I used it on both my 53mph piston port 69cc chinagirl bike, and with a larger jet on my 65+mph 74cc A35 reed moped engine bike and it performs perfectly on both. Easy to tune while still having fine control over everything if needed.

Its the KTM 50SX carb.

Ooh thanks for sharing your experiences with the actual equipment I have to work with. I feel encouraged and confident. Although I dont know how to set it up and hebent got around to even looking inside yet lol. I need to build my engines very soon. It certainly sounds like the 19.5 stamped & PHBG box labelled item was the right thing for my 50SAND project that is going to use a large 4" diameter tuned Aprilia RS50 pipe, hopefully drawing lots of extra fuel/air mix to run at mostly full throttle and not be used in the street.
You shall see the impressive air/sand/saltwater pre-filter I inherited for it haha! I have to get on with writing the intro to the build thread. I should use the notes on my on my phone.. but get some slee.... p first.