ZS250GS Technical problems

[drummerben]

I agree, this is not a bike that is built for speed or racing, but a "around the town" bike. Considering that the Chinese mostly build scooters for the small commuting, it stands to reason that building a bike that exceeds the 70's would be a bit excessive. My commute goes from 35 to 65 but I usually don't go over 55.

[motorstar rider]

hi my bike is surdging real bad at higher rpms. at about 65mph to 70 it is the worst. if i rev the engine in netural you can feel and hear the surdging starting at 6000 rpms. checked fuel delivery no problem there. any body know anything about the ignition system does it have a revlimiter ect? everything else on the bike is great just one little bug.

sir try to do some 'tune-up', your carb could be running lean or rich, you could start from 1 3/4 turn from closed position of the a/f mix screw, i sometimes run my zongshen at 70mph and above (but not beyond 74) for few minutes on clear roads and no surging at all

[gstang]

thanks for all the input and help. I finaly found that the air filter was saturated in oil changed it and eliminated the pollution stuff and it runs likle a dream. i mean really how much pollution can such a small engine emit? seems to have helped performance. thanks again for all the help

[drummerben]

gstang...
what exactly did you remove and how much speed are you getting?

[GRob-GS250]

Pollution stuff??    
Id kinda like to know what was removed as well...

[gstang]

well the little pollution pump on the right front of the bike was removed and i re routed the hoses. eliminated the small hose from the intake to the pump and to the carbon canister on the left front of the bike.Just put a vacume cap on the nipple on the intake. the crank case breather was split three ways and i re routed it directly to the air box. did leave the carbon canister with only the fuel tank vent hooked to it just in case.As far as the tube coming out of the head i took the fitting out of the head and put a small weld in it to seal it off. otherwise it would be a direct exhaust leak. I have reached 80 mph on my bike and i am a big fellow. I have a 35 mile commute to work and i average 65 mph not pushing it. I can run 70-75 but it has to be hard on the bike for that extended amount of time. thinking of regearing the bike to bring the rpms down some. also an exaust change to help it brethe. Im gonna push my little zongshen to the max see waht it can handle(without killing it). I belive this bike has alot of potential that was ruined by pollution junk.

[xanthmo]

It is a 230cc, but it is also a single cylinder.  

Do you have any pics of the mods?

[drummerben]

Hey guys...

Just got my new carb from Scooter Dynasty (finally). I installed it, but bike still won't start. I've actually gotten it to fire a few times, but nothing that catches for more that a few seconds. Is there something I am missing with installing a new carb or am I screwed.

[choylifutsoccer]

Ouch..I'm sorry to hear that.
Although I'm not too experienced with motorcycles, did you use the choke while starting it? Did you adjust all the needle settings? Is your spark plug fouled again? Is your battery still strong after it's been sitting for these few weeks? Uh..what else..oh..did you check the airbox to see if the filter element has a problem? And lastly..the most impossible of all, is the new carburetor broken too?  

[drummerben]

I hope the new carb isn't broken....I did do all of the other things you mentioned with the exception of needle settings. Are the factory settings not sufficient. I don't know much about needle adjustment, so I might need to consult someone about that.

[fletc2239]

Ok Here is my problem. The bike Runs fine I don't have a problem shifting the gears  up .the problem come when  i leave the bike to idle . It keeps shutting off . Also when I'm slowing down and I down shift the bike shuts off. This is probably an easy fix , does anyone have any suggesions..?

[drummerben]

How's the bike running...choppy, smooth--It may be the spark plug. Check to see if it is fouled. It will be black/charred. You may need to replace it. An easy, cheap fix if that's the problem.

[xanthmo]

Hi Fletc,

What RPM is your bike idling at?  The manual says 1400, but mine shuts off under about 1600, so I keep it a little bit higher.  You can adjust the idle with the long screw on the left side of the bike (opposite side of the muffler).  The screw points down from the carb and has a spring on it.  If you turn it a little bit at a time, you should hear the idle speed up, and adjust it until it stays running.

[xanthmo]

Have you had any luck yet drummerben?

[drummerben]

Not yet...I'm waiting for a friend of mine to come and look at it. It's my hope that this will fix it. If I can't, I may just try and sell it and get something else. I'm kinda at an impass right now. Frustrated to no end. I haven't been riding long, but the taste is good and I want it back.