S250 i.e. COLD start problem

[gorazdm]

Hello.

I have a problem with cold start. Battery is ok, it keeps cranking, but no sign of life from the engine, eventually the battery runs out of power and i need to recharge it.
The rear brake light works, also the side-stand switch should be ok since there are no problems with warm start (1 sec and it runs...).
I am suspecting the idle/low rev valve, which does not move more than 0.5mm ...

Any ideas?

[Tromper]

Check the side stand switch.  It might be stuck.  Double check to make sure you have it turned on of course.
Beyond that it's down to the basics, check spark, make sure it's getting gas (do you smell gas from the exhaust while it's spinning?) Vacuum leaks, ignition switch.  Wouldn't think it'd be the auto bystart but that's possible I guess.
The service manual has an OK troubleshooting guide in it.  I found a copy here www.scootermasters.com/manuals/People-250-Full-Manual.pdf if you need it.
There's also the 101 owners manual on the Kymco site, but that's probably a bit too basic.

[TLRam1]

Choke not working?

[gorazdm]

Thanks for all the advice!

... I am quite sure it is the battery. Each time I recharge it, the bike starts immediately! So it looks like the problem occurs only when the battery does not provide enough power, even if there is enough power to run the starting motor for a while. .. might be the battery loosing its stamina, or the generator/rectifier not working properly and thus not charging the battery enough.
I will check somehow the voltage on the battery and on the rectifier/regulator.

[slug50]

I bought a new 2010 S250 just this last March, new old stock, and the cold start is funny, fires right off and after about a minute it dies and I have a heck of a problem getting it to restart and keep running. Dealer said carb needs cleaned but it runs like a top once it is warmed up. They did finally order a new choke for it but waiting for cool weather to have it installed to see if that works. Even in warm weather the engine is really cold blooded, tends to stall on acceleration until RPMs are up to about 2000.

[TLRam1]

Mine does not do that, starts easy, something is amiss with yours. I take up the slack in the throttle cable, than just a shade more turn and it fires right up. You can tell the chock is on as it idles high, than slows down after a bit.

[mrbios]

Mine does not do that, starts easy, something is amiss with yours. I take up the slack in the throttle cable, than just a shade more turn and it fires right up. You can tell the chock is on as it idles high, than slows down after a bit.

Slightly clogged pilot jet will cause that as when the motor is cold it needs a richer mixture.  Mine goes even when the temp is 40 degrees with no hesitation - just a high idle because the autobystarter (electric choke) is still on max.  Clean the jets and if you want it to run like new spend $300 for a new carb + installation.

[Redk]

Good, if it might be obstruction of the pilot jet...
One of the few things that may benefit from a spray cleaner from the exterior of the carb.

Remove the rubber at the inlet to the carb, open the jet a turn, and spray into the ports using the little plastic tube that comes with many cleaning products.
After allowing it to sit for a while, start and run for a mile or so to clear the gunk from the carb and re-adjust the pilot metering screw.
The intake boot should have been replaced before running, and also verify the air cleaner is in good condition.
Bon chance!
redk

[mrbios]

Good, if it might be obstruction of the pilot jet...
One of the few things that may benefit from a spray cleaner from the exterior of the carb.

Remove the rubber at the inlet to the carb, ...
redk

... and hope for the best!

[Redk]

 

It's gratifying when a simple fix resolves problems.

I am rarely so lucky.
redk