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2005 crf250 with 13.5-1 piston and fmf exhaust jetting??

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Hey i really could use some help i just rebuilt my 05crf250 and i bought it used.. it has a 162 main jet... i live in normal riding conditions (atmosphere)... I put the wiseco 13.5-1 in it and a new wiseco crank timing chain bearings etc, stock cam and valves with some head work done.. and full fmf factory 4 exhaust... What should i run for a main jet and another other tips are really apprecaited. BTW i heard a 172 main would be better?

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If it ran fine before the rebuild and adding the pipe leave it alone. You may need to adjust the fuel screw a little but thats about it. Looks like that bike came from the factory with a 172 main jet in it. However the previous owner must have put in the 162. The 172 main jet is usually recommended for 08 and 09 250r because they came from the factory jetted really rich on the main.

I reciently put an fmf 4.1 in my 09 and didnt need to rejet.

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Per Motocross Action:

Main 175 (172 stock)

pilot 45 (42 stock)

Needle NCYS (NCYQ stock)

Leak jet 70

Clip position 3rd from top

Fuel screw 1-1/2 turns out (2 stock)

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i would just try going up on the pilot. because your pilot will affect from idle to 1/4 turn throttle. i have a 45 in mine, an it runs great. BUT, i don't have the fmf pipe on it. another thing i would suggest is getting an aftermarket air screw if you don't have one already. those make it real easy to adjust your air screw to where it needs to be. was the 13.5-1 piston what was in it stock? i am looking to rebuild mine an not sure which piston was stock or which i can use without doing anything to the cylinder or anything like that

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thanks guys i figured it out!

It wasn't old gas was it?

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i would just try going up on the pilot. because your pilot will affect from idle to 1/4 turn throttle. i have a 45 in mine, an it runs great. BUT, i don't have the fmf pipe on it. another thing i would suggest is getting an aftermarket air screw if you don't have one already. those make it real easy to adjust your air screw to where it needs to be. was the 13.5-1 piston what was in it stock? i am looking to rebuild mine an not sure which piston was stock or which i can use without doing anything to the cylinder or anything like that

If I were you id just go to to crf's only and get thhe je piston kit or wiseco kit, compression doesnt matter but the size needs 2 be 78mm for stock but you still can get the high compression 13.5-1 instead of 12.9-1 or 13.1-1.

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Need help with my sons 2005 honda crf 250 r that he raced. New 1.5 striker crank, new cylinder works 256 big bore kit, new stage 2 cam, new factory valves and springs installed by honda shop. The bike is hard starting have to kick your but off. After it runs awhile still hard to start, push starts fine an runs like a beast. I think it is jetting any help on this is appreciated. Before the rebuild with stock parts bike fired up on 1 to 3 kicks everytime

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