Runtong jets and upgrade

How are these carbs? Even though im a big NT carb fan the only issues i had with nt carbs where going over many bumps for years the float level slowly creeps up from being bent up when the float jumps upward over a bump starts too leak gas really bad and stall really easy fix though just have too bend it back down
They are great carbs for these little china girl engines but, like I said, you have to find the right jet size, there is no clip to make it run leaner or richer so it's all in the jet size.
 
you can buy a torch tip cleaner and use that it works great if your looking on making the jet bigger
 
J- E- T- S Jets- Jets- Jets!

Ok- finally have Jets in hand. The stock is not marked so I thought I would try the #70 first. In all fairness I also switched from break in gas at 20:1 to fresh 40:1. I know if this were a proper experiment I would only change one variable- don’t turn me in to the ethics board.

The #70 was worse- throughout the throttle range. Barely a 2-stroke anywhere. Not surprised, but worth the effort to confirm. Barely got 23mph. Since that was clearly off I jumped to #67

The #67 was much better. More torque it seemed- good 2-stroking through ¿ say 40-80% throttle. May have a new top speed of 26mph, so that’s nice. But wot runs crappy. I didn’t climb any hills- a was hungry and half soaked in 2 cycle gasoline.

The size difference in these is half of nothing. My beautiful bride can see it- I can not. I have #61-#70 in single steps so mor fun to come. Oh- the temp of the head was basically the same after each run- roughly 275*F
 
J- E- T- S Jets- Jets- Jets!

Ok- finally have Jets in hand. The stock is not marked so I thought I would try the #70 first. In all fairness I also switched from break in gas at 20:1 to fresh 40:1. I know if this were a proper experiment I would only change one variable- don’t turn me in to the ethics board.

The #70 was worse- throughout the throttle range. Barely a 2-stroke anywhere. Not surprised, but worth the effort to confirm. Barely got 23mph. Since that was clearly off I jumped to #67

The #67 was much better. More torque it seemed- good 2-stroking through ¿ say 40-80% throttle. May have a new top speed of 26mph, so that’s nice. But wot runs crappy. I didn’t climb any hills- a was hungry and half soaked in 2 cycle gasoline.

The size difference in these is half of nothing. My beautiful bride can see it- I can not. I have #61-#70 in single steps so mor fun to come. Oh- the temp of the head was basically the same after each run- roughly 275*F
Well it sounds like you are headed in the right direction👍
I'd p probably try the 65 next and see how it goes. No matter how hard I beat on my bike I haven't had it get over 385°F
I'm kinda hard on it as you can see
Screenshot_20190805-195559_TripMaster Speedometer.jpg
 
Well it sounds like you are headed in the right direction👍
I'd p probably try the 65 next and see how it goes. No matter how hard I beat on my bike I haven't had it get over 385°F
I'm kinda hard on it as you can see
View attachment 89714
I have hope for a brighter future. - is that an app? I’m using my garmin watch for speed checks. I would like a good app for the phone I could mount on the handle bars.
 
I have hope for a brighter future. - is that an app? I’m using my garmin watch for speed checks. I would like a good app for the phone I could mount on the handle bars.
Yup it's an app from the play store.
Here's the link for you.
 
J- E- T- S Jets- Jets- Jets!

Ok- finally have Jets in hand. The stock is not marked so I thought I would try the #70 first. In all fairness I also switched from break in gas at 20:1 to fresh 40:1. I know if this were a proper experiment I would only change one variable- don’t turn me in to the ethics board.

The #70 was worse- throughout the throttle range. Barely a 2-stroke anywhere. Not surprised, but worth the effort to confirm. Barely got 23mph. Since that was clearly off I jumped to #67

The #67 was much better. More torque it seemed- good 2-stroking through ¿ say 40-80% throttle. May have a new top speed of 26mph, so that’s nice. But wot runs crappy. I didn’t climb any hills- a was hungry and half soaked in 2 cycle gasoline.

The size difference in these is half of nothing. My beautiful bride can see it- I can not. I have #61-#70 in single steps so mor fun to come. Oh- the temp of the head was basically the same after each run- roughly 275*F

Good News! Just keep working your way down until the 4 stroking stops, if it's not 4 stroking, you found the right jet! Just remember that most China girl engines tend to run slightly leaner after they are warmed up, make sure you get it hot before you make an analysis because sometimes the 4 stroking will stop after the engine is hot. Also, it's always better to be a little on the rich side rather than too lean, too rich and it 4 strokes, bogs, and suffers performance loss but if it's too lean it will run too hot which will cause major parts failure.
 
The size difference in these is half of nothing. My beautiful bride can see it- I can not. I have #61-#70 in single steps so mor fun to come. Oh- the temp of the head was basically the same after each run- roughly 275*F
Dang, that's a very cool head temp. With the stock head I was seeing 350-400 (105-110f weather) and 325 to 350 with an aftermarket.
 
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