rejetting carbs

[glennbo]

i want to rejet my stock nt carb i live in the chicago area i know that elavation, humidity, and temp all play a part in performance i have astock 66cc 2 stroke with expansion chamber i want to know what size jet to get to improve performance i would appreicate some of your wisdom as i have little. i will also run the stock chrome air cleaner.

thanks glenn

 

[Goat Herder]

First you will need to verify the basics. Where is the needle clip at on the carb throttle body [metering rod]? What ratio of oil are you using? Also what color is your spark plug?

 

[glennbo]

i have the needle clip 2nd from the top im running 50:1 ams oil the plug is blckish/brown

 

[Goat Herder]

Then you have part of your answer. Solder the jet shut and red rill it one size smaller. I would get micro drill bits from harbor freight. Use a bit to find out where you are now. Then pick a bit just a bit smaller.

That is how I would do it. I kinda like the plugs at a darker brown myself. Have you tried a hotter plug?

 

[glennbo]

do you use regular electronics solder or do you have to use silver solder?

 

[Goat Herder]

Shoptalkforums.com • View topic - HOW TO - resize carburetor jets

I have been using silver solder tho.

 

[glennbo]

thanks for ther link very helpfull ill give it a shot this week and let you know the results .
THANK AGAIN GLENN

 

[Venice Motor Bikes]

Sick bike parts sells jets... Usually just one size smaller is what works best.

Don't try to re-jet the carb until you have at least 5 gallons of gas through the engine!!! Because it will keep running better & better the more it breaks in (& you might not even have to re-jet.

 

[DanielMaia]

Usually i put some loctite on the main jet, take some 15 or 20min to dry, redrill the holl, and its perfect

 

[camlifter]

i'm at 900 ft el. with weather close to chicago, after a short break in all my engines have ran best with the clip on 2nd notch from the top and the jet soldered up and redrilled with a #73 bit. that includes engines with expansion chambers and porting too.