hey all new guy here , I just picked up a little 2000 eton 50 for our granddaughter Very used. the piston was rattling really bad so I bought a top end kit for it and installed that. ended up with 130 psi. the carburetor was pretty worn out from being taken apart so many times so I got a new one. I also retrofitted a muffler off a lt250r to it because the factory one was blown out and leaking oil all over . my question is, I put it all together and it was lean, I had eliminated the oil injection on it. I put a clamp on k&n on it and it doesn't want to rev all the way up. starts up like a champ though. I actually had drilled the main jet out of the old carb out a spec. but is there is set jetting for eliminating the oil injection and running a open air filter? with the new setup on it , it acts like it wants to run pretty good til about 1/2 throttle . I haven't moved the needle yet. its still new and its smoking pretty good at 32:1

 

IDK I would probably pull off the air filter., start it rev it and manually choke it see if it revs better. Then idle it and manually choke it out, see if it keeps running (intake leak). At least you will know weather to jet it bigger or fix an intake leak. Sorry thats all I got.
Dave

 

i have the same problem! I just picked up this 50, has killer compression, idles and throttle response is awesome, but falls on its face at about half throttle. I know its fuel starvation. I currently have a .75 jet in the main and I moved the needle on notch higher. it helped some, but it needs more. im thinking the needle(and seat) needs to be adjusted to allow the carb to keep up. my other sons 90 runs great on an 85 jet, so I don't think it needs more jet.