I just did a endcap mod and jetted.When it was warmer it ran great.I went to ride
yesterday and it fell flat on its face at take off,higher rpms its fine.Ive got 170 main
needle on the ritchest,stock pilot.I did not mess with the air fuel.Do i need to change
my pilot jet , or is the needle to rich,or is it the air fuel mixture.
And yes i did read the 4 pages on jetting and still confused.[img]i/expressions/face-icon-small-smile.gif[/img]
I gotta go to work ill check when i get home.

Thank you for your help

 

I would put the needle back where it was and the 170 sounds pretty close( keep an eye on your plug ).

 

You get richer as the temps get cold. I would try what SpinCycle says first. Must get really really cold there to affect you that much[img]i/expressions/face-icon-small-shocked.gif[/img]

 

Sorry it took so long to get back, long day.When i rode it it was about 40 degrees
My plug was black but not wet.Thanks for the help thats what i was going to try first.
Dont know why i was but that was my first thought.[img]i/expressions/face-icon-small-smile.gif[/img]One day i might figure it out.

 

You get leaner the colder the air temp gets, not richer.

 

[img]i/expressions/face-icon-small-blush.gif[/img]
I can never remember that one for some reason. I always get it backwards for some reason. I just thought it made sense that colder temps less air / higher altitude less air and colder temps.

I used to have a jetting slide rule that told me all this good stuff so i didn't have to rely on y lously memory. [img]i/expressions/face-icon-small-confused.gif[/img]

 

Is it colder air is more dense=more air(leaner) & hotter air is less dense=less air(richer)?

 

You are correct. Here is a small section from 4stroke.com's jetting section.

For our second example let's say we are still at our new 4000-feet elevation riding area and a storm comes in. We head back to camp and ride it out overnight. The next day there's a foot of snow on the ground the skies are clear and it's COLD! Aside from getting the campfire going and making some coffee you should be thinking about jetting again! Cold air is dense air and dense air requires bigger jets. If the 140 jet ran good the day before you will need a bigger jet to run properly today. If the temperature is 50 degrees colder than it was the day before you can actually go back to your sea level jetting, a 160 main jet! If you don't rejet you can kiss your assets goodbye when you rebuild the seized engine. Air temperature makes that much difference!

 

I just added a RWR CDI and an billet end cap from on dunes, I started with a 170 main also but that's too fat. I'm going to go down to a 167.5 maybe even back to a 165. Before these mods I had a 162.5 main and that was right on, nice clean plug. needle and pilot stay where they are at, the low range and middle are good. If your plug has any black on it you are slower than you could be[img]i/expressions/face-icon-small-smile.gif[/img]

Lean is fast! fat is slow... just the way things have always been[img]i/expressions/face-icon-small-smile.gif[/img]