Jett size and reeds? Increase power on a yz250

I'm wondering what size of main and secondary jets I should get for my 96 YZ 250. My year of bike has a certain carb that doesn't want to idle and I'd like I try to fix this, as well as increase power. What size should I run? What size do you run? And does it make a diffence in carb size and year what ripe of jets I use, as long as its a yz250? Also what reeds? I don't know to much about intake, fuel to air ratio, and getting performance from intake parts.. But it seams my bike is running rich on fuel or no enough air. The year has the idle adjustment on the choke and if I adjust it it still Boggs out and stalls if I let go of the throttle. Any tips?

You should post this in the YZ forum

You cannot 'boost power' with jetting, you can only correct bad jetting which is creating too lean or too rich mixture.

My 96 idles fine, I would order main jets from 162 on up to 180 and pilots from 42 to 50 whatever they come and read the jetting sticky and get to work. Jets are cheap and are good to have around.

Also when I got my bike it ran rich no matter how lean of a main jet it had in it , turns out there was a chunk missing out of the cylinder but it still ran good just always smoked.

Point is that other things could be wrong with your bike that's causing this I.e. worn top end, bad crank seal etc.

The idle circuit on the choke idle is clean?

The idle circuit on the choke idle is clean?

haha good to see you again. I just bought a carb soaking solution from the Yamaha shop an they told me if any dirt is in there, it will be cleaned out with this. So ill make sure to figure out where this is, and take a good look at it specifically. Thank you

My 96 idles fine, I would order main jets from 162 on up to 180 and pilots from 42 to 50 whatever they come and read the jetting sticky and get to work. Jets are cheap and are good to have around.

Also when I got my bike it ran rich no matter how lean of a main jet it had in it , turns out there was a chunk missing out of the cylinder but it still ran good just always smoked.

Point is that other things could be wrong with your bike that's causing this I.e. worn top end, bad crank seal etc.

So you have your stock jets in? 175S main? Exc. The service guy from the Yamaha shop said the carb adjustment has a bad flaw and the carb was defiantly not a good carb. He said people call all time about the bikes of this year reporting the same thing. He recommended me to change my jetting but he doubted it will ever idle like it should.

haha good to see you again. I just bought a carb soaking solution from the Yamaha shop an they told me if any dirt is in there, it will be cleaned out with this. So ill make sure to figure out where this is, and take a good look at it specifically. Thank you

 

 

No problem :) I'd use compressed air and would not trust just a cleaning solution eating away dust and particles.

No problem :) I'd use compressed air and would not trust just a cleaning solution eating away dust and particles.

Forgot to mention! He said soon as you pull it out blow it off with compressed air. Your right on the ball man haha. Thank you for your help brother!

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