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Cinders!

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could some one help me jet my bike for the the cinders... I have a 02'cr250

I will be riding it at about 7000feet

How many sizes down on the main, pilot , and needle?

How many air screw turns.

anyone ever set up a 02' cr250 to ride between 7000 and 8000 feet?

thanks alot!!!!!!!!!!!!!!!!!!!!

👍

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Neither, go up on the main 2 or 3 sizes. Pilot, he he, at the Cinders you are full throttle or full stop. no in between. You'll see. You want to ensure plenty of lube and cooling, and to do so requires more oil. It will avoid detonation and ensure the motor survives. The Cinders is really hard on the motor. It is like riding in a bowl of dry rice.

Good luck!

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on bretts 450r he did nothing and ran good my ktm on the other hand had a hard time on the idle but wide oped it was fine.like ebeck said you ride there wide open so i would not do to much

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Let me clarify, if it is a 4 stroke you do nothing. If it is a 2 stroke go up on the main 2 sizes at least.

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actually it all depends on the altitude and conditions you are coming from, but you do have to jet 4 strokes (well you dont have to, unless you dont want your bike to run its best). ussually you have to jet 2 and 4 stokes leaner in higher altitude. but anytime you go to the cinders or the dunes its opposite for 2strokes only. you always have to have the main jet air/fuel ratio richer to keep the motor cool in sand and cinder type conditions. it works the motor harder causing more heat and require more oil at extended higher rpms. my 2 stroke is far less picky about altidude and jetting than my 4stroke is. bretts ran well because his bike is too lean here in the valley, alecs was worse on the pilot till i fixed it.

i would go up 2 sizes on the main, raise the needle a clip or 2, and do a plug chop/read, i wouldnt be concerened with the pilot too much, when are you going to the cinders?

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I am heading up there this weekend! I understand that the bike works harder and Im going to need more cooling/lube. but the air is way thinner being so high in elevation so i though to jet down to correct the fuel air mixture....?? So i should go up on the main jet size and then play with the fuel air screw to get it running good and not bogging??? thnaks again!

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airscrew only affects the pilot which is not used at the Cinders.

Forget the elevation thing. You are not sight seeing on easy trails. Go up 2 on the main for Cinders riding. 👍

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I am heading up there this weekend! I understand that the bike works harder and Im going to need more cooling/lube. but the air is way thinner being so high in elevation so i though to jet down to correct the fuel air mixture....?? So i should go up on the main jet size and then play with the fuel air screw to get it running good and not bogging??? thnaks again!

your thinking is correct, but like i said, cinders and dunes require a much richer mixture. the cinders would have to be at 15000+ ft for you not to have to richen it up. airscrew wroks in conjustiomn with the pilot jet for the pilot circuit. leave the jet alon and adjust the screw to get a nice idle and smooth transistion to the needle

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I avoid the cinders whenever possible, but when someone does drag me kicking and screaming off the good trails my normal Flag jetting works fine.(Same main as Sycamore, -1 clip on the needle, out +/- 1 turn on the air screw) This for an 06 250XC, YMMV.

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No one else is heading up to the Cinders this weekend?!!?!?!?!?!!??

i really want to, but no time really to go that far. maybe ill DS up there on my paddled drz

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