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General => Technical | How To => Topic started by: blue on December 02, 2010, 02:07:01 AM

Title: carb help
Post by: blue on December 02, 2010, 02:07:01 AM

ok I have a nst with a gy6 engine in it its also a 50 cc runs rough in the cold im thinking of playing with the carb should I tune the carb to take more gas in or less. the summer time the scoot runs great.

Title: Re: carb help
Post by: oswaldters on December 02, 2010, 02:32:25 AM

I have read that the theory is the cold air in winter is associated with  higher pressure so it throws off the air/fuel mix by adding more air into the mix.  Therefore, you would want a bigger jet to increase the amount of fuel in the mix.

Haven't tested it myself (yet), so take it with a grain of salt...

Title: Re: carb help
Post by: ts1 on December 02, 2010, 08:56:02 AM

Quote from: oswaldters on December 02, 2010, 02:32:25 AM

I have read that the theory is the cold air in winter is associated with higher ...

density.

Title: Re: carb help
Post by: Rianna on December 02, 2010, 01:21:45 PM

So...if you weren't re-jetting...you would turn the fuel mix screw to allow for more fuel intake??

Title: Re: carb help
Post by: blue on December 02, 2010, 01:33:59 PM

thank you much guys. just needed a little reasuring

Title: Re: carb help
Post by: Rianna on December 02, 2010, 01:42:42 PM

Good luck, blue! Let me know how it turns out and hope it runs better. :)

Title: Re: carb help
Post by: oswaldters on December 03, 2010, 01:03:26 AM

Hey blue, is the scoot running rough at idle? 

Or is the problem while you are riding at speed?

Title: Re: carb help
Post by: blue on December 03, 2010, 01:08:19 AM

yes a little at idle have to keep throttle up so it well not stall out at times.sometimes when I come to a stop it stalls out.

Title: Re: carb help
Post by: oswaldters on December 03, 2010, 01:10:55 AM

Sounds familiar! 

Adjusting the mixture screw should help that

the other thing that I do in winter is increase the idle speed a bit as well as this has helped me with the low-idle problem.

Title: Re: carb help
Post by: blue on December 03, 2010, 01:24:29 AM

ill give it a try another thing i was going to try is a higher oct. gas

Title: Re: carb help
Post by: oswaldters on December 03, 2010, 01:32:58 AM

I run 93 and I have the same symptoms once the cold weather hits.  Don't think the higher octane will help you with it.

If I warm the scoot fully before I ride, the problem doesn't occur.  Mostly it happens on the way home from work because I get impatient and take off before the scoot is really warmed (hey, dinner is waiting!) 

Not so much of problem in the morning because I can just go back inside and stay warm while I let her warm up.