NT Speed Carb vs Racing Carb

Status
Not open for further replies.

Sharif

Member
Local time
9:11 PM
Joined
May 28, 2019
Messages
111
Location
St. John's
This would be my first upgrade to my bone stock 2 stroke engine after the spring loaded chain tension I will be buying.

Wanted to know what's the difference between/which is better?

They both look different and the speed carb is known to be good or atleast I heard from an awesome guy locally.

The items in question
Speed Carb
https://www.motorizedbicycle.ca/nt-speed-carburetor-gen-2.html

Generic Racing carb I am seeing everywhere
 
I prefer the generic racing carb you have listed. Those are great carbs for these little engines but make sure you get some jets, you will probably need to jet down.
 
Nt carbs work great if you get the right one yes there is different ones you can get that look almost the same i have 2 that have different slide and needle sizes
 
I ran around 5 nt carburetors some are the same some are different its kind of the genuine nt carbs vs reproduction . some reproductions are trash and some are actually really good.
 
Nt carbs work great if you get the right one yes there is different ones you can get that look almost the same i have 2 that have different slide and needle sizes
I'll go with the one on that site since it seems more trustable
 
What do you mean by jetting down?
I mean, putting a smaller jet in the carb. Those carbs come with a #70 jet, however, most of the time it's too rich causing 4 stroking, usually jetting down to a smaller size jet will make it run at the correct air/fuel ratio. Often times when you get the carb you get THESE 5 extra jets however The stock size jet (#70) is usually too rich and the #75 and #80 are far too rich. If you really want to dial it in get a set like these----> https://bicyclemotorworks.com/product/jet-pack-combo/ You will need to test each jet until you find the right one for your engine. It's best to start high and work your way down until you find the right one that makes it run good.

----> https://bicyclemotorworks.com/product/fine-tuning-jets-high-60s/
----> https://bicyclemotorworks.com/product/fine-tuning-jets-low-60s/
 
Links to eBay may include affiliate code. If you click on an eBay link and make a purchase, this forum may earn a small commission.
Some of the speed carbs have a slightly larger slide, and stronger spring. Different NT types have different needle lenghts and notch counts. I prefer the real NT or the speed with 5 notches over some of the knock offs with 4. The Speed/NT's are more prone to floats sticking. The racing/ Dellorto clone carbs sometimes come as a 14/14, sometimes as 15/15, and tend to run a little richer than the NT's. They are all good carbs.
 
I mean, putting a smaller jet in the carb. Those carbs come with a #70 jet, however, most of the time it's too rich causing 4 stroking, usually jetting down to a smaller size jet will make it run at the correct air/fuel ratio. Often times when you get the carb you get THESE 5 extra jets however The stock size jet (#70) is usually too rich and the #75 and #80 are far too rich. If you really want to dial it in get a set like these----> https://bicyclemotorworks.com/product/jet-pack-combo/ You will need to test each jet until you find the right one for your engine. It's best to start high and work your way down until you find the right one that makes it run good.

----> https://bicyclemotorworks.com/product/fine-tuning-jets-high-60s/
----> https://bicyclemotorworks.com/product/fine-tuning-jets-low-60s/
Seems like I am better off getting my hands on one of these kits before getting a new carb
 
Links to eBay may include affiliate code. If you click on an eBay link and make a purchase, this forum may earn a small commission.
Status
Not open for further replies.
Back
Top