Yz250 won't start without idle adjustments

[How could I not]

It's becoming colder at night here in Colorado and my yz is becoming harder and harder to start. I have found if I loosen the idle screw kick it thanks tighten it, kick and she starts. Anyone know why? Is my pilot jet dirty and needs to be more or less lean to start? I'm pretty clueless. Thanks

[jmd426]

It's becoming colder at night here in Colorado and my yz is becoming harder and harder to start. I have found if I loosen the idle screw kick it thanks tighten it, kick and she starts. Anyone know why? Is my pilot jet dirty and needs to be more or less lean to start? I'm pretty clueless. Thanks

 

Are you using the choke

[How could I not]

Yeah I use the choke

@jmd426

[AnthonymYZ250]

What year is the bike

[clappedoutkx]

If it has been running well and only now has become hard to start with the weather change, its likely not because the pilot jet is dirty. Adjust your airscrew inwards according to spankys jetting guide. You may need richer jets. You almost definitely need a richer main, if its been running well up until now. Adjusting your carb for the winter is super important because running lean murders motors. Let us know what jets you are using and your altitude and temp range.

[How could I not]

What year is the bike

an oldy 87 freshly rebuilt top end tho

[AnthonymYZ250]

Have You have adjusted the idle with the choke

[AnthonymYZ250]

Check the reeds make sure there clean and what plugs are you using

I use BR8EG (fine wire nickel electrode)most of the time; but you can use the BR8ES (standard copper core electrode) as well; the BR8EG just resists fouling a bit better due to the fine wire tip (and costs a bit more).

A BR8EIX is an iridium tip plug; which is a step up from the BR8EG ( and also costs more...)

The BR8EV is a fine wire gold tip electrode.

http://www.spark-plu...ical/ngkjpg.htm

[AnthonymYZ250]

If you have put in new jets they may be to small

[How could I not]

If it has been running well and only now has become hard to start with the weather change, its likely not because the pilot jet is dirty. Adjust your airscrew inwards according to spankys jetting guide. You may need richer jets. You almost definitely need a richer main, if its been running well up until now. Adjusting your carb for the winter is super important because running lean murders motors. Let us know what jets you are using and your altitude and temp range.

I live in Denver a mile above sea level. It's probably 40-50 during the day right now and maybe as low as 30 at night. I have also ran my gas tank dry twice recently as well. I might have A dirty petcock or something. Runs great once I get here started. I warm here up rich then loosin the idle when riding

[clappedoutkx]

What jetting and airscrew setting are you using? Did it start and run well in the warmer weather and now it's getting harder and harder to start as the temps fall? I'm assuming you have a fresh, clean, and properly oiled filter, good reed petals, and a properly packed silencer.