# Mini Bike with JF168 5.5 HP Jiangdong engine won't stay running after rebuild



## Boojie_007 (Jun 11, 2012)

I had to replace blown rings on this engine, I got it all back together and it will start and run for about 10 seconds then dies. Also if I try to give it any gas at all it will die even sooner.

It seems to be getting air and fuel good, and it sounds good while it's running.

Any ideas on what may be wrong?


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## Rentahusband (Aug 25, 2008)

Sounds to me like a carb issue. Did you clean the carb? How about compression?


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## Boojie_007 (Jun 11, 2012)

The compression feels really good.

I did clean the carb. out pretty good (as good as you can without taking it all apart. It was sitting dry while it was waiting for the rebuild so it should not be gelled up. I did have trouble with the float sticking WOT at first, but I opened the bowl and cleaned it up in there. I made sure it was clean and working and it stopped dumping fuel on the floor.

A friend told me these things are really picky about having a good ground, could it not be getting a good enough spark? Or, would that be more apparent at idle?


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## 30yearTech (Sep 14, 2006)

I agree with rentahusband, it's a carburetor issue. You need to make sure the main jet and nozzle are clean, and that there are no air leaks between the carburetor and cylinder head.


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## Rentahusband (Aug 25, 2008)

Boojie_007 said:


> The compression feels really good.
> 
> I did clean the carb. out pretty good (as good as you can without taking it all apart. It was sitting dry while it was waiting for the rebuild so it should not be gelled up.


As 30 year mentioned. You need to make sure the main jet is *Clean* This requires removing the main jet and cleaning the little holes. Was the carb drained prior to sitting? If there was any fuel left in the carb to evaporate it could have varnished and blocked something.


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## Rpeters123 (Oct 19, 2005)

*Adjust the valves to .004 -.006 NOT the .002 they say.*

I find most chinese engines act really strage when the valves beat in to .000 lash or are set to only .002 inches not metric. Most engines valves / lash must be reset OFTEN 500 to 1000 miles max.:thumbsup:


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## 2men&atrailer (Mar 22, 2011)

*fix*

i have done the same job that you have done there and i just put on a new carb because it cost more to rebuild that it done to just put on a new one 

i think you might have had this problem before rebuild but couldn't see it for the bad rings

what i did to get a new carb is look on the covers and you will see that it is 196 cc or what ever and then ebay that info and you should see them for sale 

this is just a ******* talking so treat it just like that

i love this place

thanks:wave::wave::wave::wave:


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## Boojie_007 (Jun 11, 2012)

Thanks for the tips guys, I will be trying them over the next few days.


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