Hi, so I finally got my bike running, turns out it was a carb issue, but it's so slow. Top speed is 22 MPH and only 13 or so going up hill. I'm running a 36 tooth sprocket, nt carb, and ngk spark plug. 40:1 mix. From everything I've seen these things can go WAY faster than mine is going. I know I'm still in the break in period but still doesn't seem like I'm getting everything this engine should be able to give.
I'm also at 6000 feet elevation, running my carb in its leanest setting. Any help or advice would be appreciated.
It's a combination of altitude and low gearing, by the time your bike gets enough breath, it's out of gear. I bet you will have more reasonable speed with a 44 tooth sprocket. Of course to change, you might need a new chain.
Stock tuning on the carbs sent with the kits is super rich even close to sea level.
Most riders run 25:1 conventional for break in and 32:1 there after. It is your engine and you can do whatever you please but I believe the advice of 40:1 cradle to grave is wholly malicious. Its not exactly a conspiracy theory but some joker selling a stage infinity custom isn't exactly trustworthy.
Assume a 26 inch wheel, it is my opinion that your gearing is too tall for a pre break in china doll. Break in greatly helps with torque but since you're four stroking and pre break in it will be super anemic, explaining the relatively poor performance. Sounds like you're getting less than 1 horse power out of it at present. I have athlete's asthma I can make those speeds pedaling my regular bikes. These kits can run around 2.5 hp at 7k after break in with a good tune.
Edit: This bit is irrelevant for this build but I stand by it.
Getting ahead of myself but, what is your braking like? I hope its not a coaster brake only. The sensibility of a coaster brake is contentious for this application but I believe a well made coaster brake, when modified for improved performance and durability is sufficient provided a properly set up front brake is used.
Here's a great video on such modifications. And a brief list explaining my understanding of the reasons why.
High temp grease helps with overheating issues inherent to all drum brakes, which a coaster brake is.
The chromoly axle is stronger but less ductile, however since the bending of an axle makes it FUBAR this is no problem.
Chamfering of the pads helps with grease flow, which helps with lubrication and cooling.
Removing the bearing cage and installing more balls reduces the load each individual ball has to support, thus increasing the service life of all the balls.
t's a combination of altitude and low gearing, by the time your bike gets enough breath, it's out of gear. I bet you will have more reasonable speed with a 44 tooth sprocket. Of course to change, you might need a new chain.
I think you just might have something there about going to the larger sprocket at the OPs 6000 ft altitude...When I was finishing up my high school before going to college up in Big Bear Lake California, I was cooking in a restaurant/bar up there on weekends...Myself, as well as the kitchen staff, were taking bets with each other on the flatlanders coming "up the hill" for the weekend for skiing etc. on the folks lined up at the bar ordering drinks if it would take two or three mixed drinks before they hit the floor because their bodies hadn't adjusted to the thinner air due to the altitude difference coming directly up the mountain from an L.A. sea level elevation.
It was quite entertaining...lol.
With that in mind, these little 2 strokes don't have a chance to "catch their breath" at 6000 ft before the gear tops out, especially with a 36 tooth sprocket...Mine running a 36t sprocket at 4500 ft im fine, but thinking of what you just said, coupled with my grins and giggles watching flatlanders pass out from only 2 or 3 drinks at 6000 ft, it makes sense that the gearing should be with at least a 44t sprocket.
NGK BR6HS gap is between .025" - .030"
If ya don't have feeler gauges or a S/P gap tool your drivers license or credit card can be used it's thickness is between .025" and .030"
My CA. D/L measures .030" thick