Carby need help tuning

[alpha]

i have read about jetting and such, i got myself a new motor, not sure what size it is, may be an 66, is what the guy i bought it from said.

ive messed with needle settings, but nothing makes it run like it should. i am running a muffler from my 49cc.

the only way it runs correctly is when i hold the brakes so the motor feels more of a load. if i dont it sounds like its 4stroking. im great at tuning a normal engine but a 2 stroke im still learning. please help

 

[alpha]

no comment??

 

[alpha]

at full throttle it feels like 4 stroking. at half it is fine till it plateaus out and it sounds funny like its 4 stroking. do i need a bigger carb, and how can i tell what motor i have, it looks a bit better built than the last engine i had

 

[alpha]

now that im looking it up it has the same outer fins on the head as the jet motors those are the only engines that i have found with the same head. and square grommet for the wires and the beefy build, and round insted of squared fins on the cyl, so the unit looks more round than square

i also pulled the head and compaired pistons in diam. and looks the same as the 49cc, so unless the stroke is longer i cant tell.

 

[alpha]

as cool as it is posting to myself, and asking for help, ive ordered a speed nt carb, people say its way better and i like the shut off valve at the carb...good idea. anyways someones input would be nice

 

[Greg58]

Don't let the lack of power bother you just yet. My first build would not pull itself. But after doing a few mods like port matching,carb jetting, sbp air cleaner and exhaust plpe porting my bike is the best running of the five of us that ride together. One thing I do to a new build is get the spark plug color right so I don't run it lean and damage the engine then just ride. After breakin it should get better.

 

[alpha]

i made a new post for my issues, look up my other posts, new cab and all