Engine won't stay on

[Mr. Furious]

I've just gotten my new bike and filled the battery.  Waited 20-30 minutes as the instructions say with the battery.  Put it in and start the bike.  It starts and stays alive for about 5 seconds and then die's.  I am using premium gas, choke it all the way and even adjusted the idle.  It just won't stay on.  Is there something I'm missing?

[dustyone]

This is very common.  I always add some "Sea Foam" motor treatment to my gasoline before trying to start the engine for the first time.  It is recommended to drain some gas out of the carb also with the scew at the bottom.  This is because the tank is coated on the inside with a film to protect it from the salt air during shipping.  The film will dissolve in gas, but sometimes it is like jelly and clogs the low speed jet.  Worst case you need to clean the carb.  You can also check you are getting gas to the carb by disconnecting the line at the carb (be sure to have no fire around and an extinguisher handy).  I have also seen the petcock not set to open (but still get some fuel through).  The air mixture may not be set lean enough for it to idle properly, also.  Hope this helps...I know it is frustrating.

[Mr. Furious]

Well, the gas tank is full unfortunately.  I would hate to drain the whole tank.  Will the film desolve on it's own eventually?  Or can I just run it ot?   Thanks again for the help, I thought I got a bad one.

[VegasTech702]

just checking, you did of course charge the battery first right? My bike doesn't like to have the choke on. try taking it off.

[Mr. Furious]

Actually, I still have to run the bike with the choke half way on.  If the choke is totally off, the bike will Die, even if it's warmed up.  I did charge the battery but everything still looks dim.  I charged it for about 24 hours on a battery tender.

[VegasTech702]

It really seems that your problem lies within the carbeuration. It sounds like the jets are plugged up. You need to cut the fuel off from the selector on the right (driver) side of the bike. you can remove the float cover on your Mikuni carb from the left (driver) side of the bike and remove the jet carefully with a  screwdriver then blow through the carb and venturies with carb cleaner. That should help. I had do that with my bike when I first got it due to the fact that my bike had sit for over a year with old gas. Also try changing the spark plugs after doing this as running it on half choke for extended periods of time with out running on no choke thereafter could have fouled them prematurely. Just my $.02

[Mr. Furious]

Just to confirm what your saying.  I can do this procedure with the carb still attached to the bike or do I have to completely remove the carb from the bike? 

[VegasTech702]

Yes I did this procedure on my LF250 with the carb still on the bike. I did have to detach the fuel selector switch from the tank to gain access.

[Mr. Furious]

Amazingly even after meticulously cleaning out the entire carburetor, jet included and every little stinking hole, it still does the same thing.  Adjusting the idle screw doesn't help either.  Gosh, what could it be at this point?  The Battery or the spark plug?

[VegasTech702]

I would check the spark plug to make sure it isn't too fouled, but I believe it is not the cause of the problem you are having. There is a ignition module type thing in this bike I do not know to much about that could be the issue or you have a vacuum leak somewhere possibly.

[Mr. Furious]

Might be a vacuum leak then because I changed the spark plug.  The old one looked pure white which means it's probably not getting enough fuel.  I have also changed the battery to a high end Gel and it still will not stay alive on no choke.  Looking at the old spark plug caused me to open up the fuel adj screw below the Float cover.  Even so still no luck on no choke.   However, I do notice now on half choke that the bike runs alot better and I can go past 50mph easy.  Wonder what is going on with the bike?

[Martin]

Try this mod:
http://www.chinariders.net/modules.php?name=Content&pa=showpage&pid=3

I'm pretty sure it will help... 

[Mr. Furious]

So with this adjustment, the bike should stay on with no choke at all?  If it came set in the middle do you recommend placing the clip on the lowest notch?  Thank you

[Mr. Furious]

Well, I did the modification and the bike runs a little better.  Does anybody know where I could go to buy bigger jets.  I went to the dealership and they said they don't have anything that looks like the jets in the Sheng Wey Carb(LB200-B).