pw 50 wont stay running

I have an early 2000 pw50.  It quit running last year, I tore the carb apart and found the choke was frozen shut. I replaced the carb with a Chinese knockoff from ebay and a new set of reeds.  With the new carb it would fire after several kicks, run very poorly for a minute then die. I figured it had to be the carb still, so back to ebay I went. This time I bought a used, working condition, oem carb. Threw it on and sure enough, exact same problem. Took several kicks to fire, and it would only run briefly and poorly at that.  At this point I figure it has to be the top end, although I never checked the I tore the top end off. The piston and cylinder were badly gouged. Finally, this has to be my issue right? No...I put it all together this evening. Nearly as excited as my son standing next to me I tried starting it. After several kicks I realized I forgot to put gas in it. Still holding out hope, and now with a half tank of gas I begin kicking,,,and kicking...and kicking. After, what seemed like 100 kicks it fired. But....symptoms are exactly the same as before.


Im stuck, not sure where to go from here. Im thinking maybe crankseals?, but that's merely a guess.

Any suggestions on what to check next?

I had a similar issue only the bike would run (like shite) and didn't have enough power to move my 5 y/o. Changed the top end, cylinder and all and the crank. Now she runs good. Could be the cylinder is just worn and or the crank seals or crank also. It is 13 years old so its not so far fetched.

Maybe it is the start-run thumb-switch.  I have heard of them going bad before.  It could be stuck in start mode.  There should be a wire under the seat that you can disconnect to get it to start in run mode.  Make sure to reconnect it after testing. 


Other than that, I would look at the crank seals.

Edited by gsa102

I just had the same problem. I cleaned the carb on a 2006 pw that I bought. It ran great. The next time I started it it would only stay running with the choke on. So I took the carb off again. This time I also to the petcock off. Low and behold it was full of gunk. I cleaned the carb and petcock with some contact cleaner. (Be sure to clean the jets with a bristle from a wire brush) I put it all back together and now she purrs like a kitten. Try that, it's a pretty easy fix. Good luck

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