Jacob Blocker

I ended up just buying a new jug and piston set and it fixed all my problems. If it's not smoking to bad and you haven't let the engine run for to long I'd let it run for a while first.

I didn't replace the Piston and rings so I'm not sure the sepcs or anything. I got new rings just to make sure there right and I'm replacing the valve seals also. I also got up sized rings if I need them.

its a 2007 with like 4k miles. I did not have the filter on when testing it.

I got an ATV from a guy that ran out of time rebuilding an eiger 400. He put a nerma Piston and rings in. I finished it up and it smoked like a train. I took the head off and honed the walls and it looked like the rings where on the walls, but it smokes just as much. I'm confused what's wrong with this thing.

When i got my 300ex the carb was kinda wreaked, it had some sand in it that i got out, but the choke lever is melted off and the throttle sticks, what would be a good replacement, so far I have replaced the cdi with a non rev limted one and i am currently re building the engine with OEM parts/ Also i would rather not spend over $100 on the carb, but im fine with it being used if it works fine.

Alright I'll try that, also when when ever I try to start it up there is smoke coming out of the carb and engine breather, I don't know if it comes out the exhaust tho,

I have not been able to start my 300ex that I just got off a guy. I was able to getting it running once, then never again. After a week of trying to make it run I got a compression tester and it is saying about 30 psi. Is this definitely the rings just worn out or can it be something elses? I can't even make it pop when I spray stater fluid in it.

something else i noticed today is that there is smoke coming out of the carb also

I would rather not take the engine apart to find out, bu i might have to soon. The one time i was able to get the engine to run (it was cold) it had a good bit of white smoke and when i killed it it left a kinda lingering smoke at the tip of the pipe. I also find it strange how hard it is to start it, although it could just the the carb (i have cleaned it a few times).

after further looking i have a video and i also fell a bit of air coming out of the hole. here is the video - https://youtu.be/l9Z-uiFRSJ8

I have been trying to get my 300ex to start for sometime. a few days i got it to start over and over and then the next day it wont start. I do the value lash and keep the covers off. I was (prob exhaust) smoke coming out of the covers with for the valves. I also noticed that the crank position marker had smoke also coming out, but i just thought it was from the head and it being in the cold. The hole for the position marker also has air come out when it turns over, but it is very light of air flow.