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2004 crf250 to a 302?

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Im new to the forum and im sure this topic has a bunch of threads already but I need to lay out my situation and have someone let me know if i can or not/

I have a 2004 crf250r . This bike was giving to me like 5 years ago. i never rode it much and have only accumulated about 40 hours or so. recently the motor has gotten noisy fast. I took it down to a friend who owns a bike shop near me and he confirms a crank issue. He has an athena 280 kit on his shelf and also a spray nozzle from an 2005 case. told me to put the nozzle on put the athena kit on and get a stroker crank to make my bike a 302. . My question is he tells me its a direct bolt in situation?? can anyone tell me if theres truth to this? or do i need a cylinder spacer or do i have to machine the cases? athena says direct bolt in no machining necessary and stroker crank with i believe a +3mm offset states its a direct bolt in no modification necessary? .

-Am i good to go or am i gonna get the crank, the athena kit, and find out i need to find a machine shop too haha.

-also can i replace the spray nozzle on the 2004 case to the 2005 nozzle and be good or is there other differences in the cases from year to year??

-Or can i not even switch the nozzles to begin with?

-will the stroker crank work with my stock ignition curve?

-or do i just put a crank and mains in and just keep riding it

any resonse or redirect to a thread already going on this would be great!


Edited by doug250

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Because I've had litte experience with the 04, I can't tell you that the oil nozzle is a direct bolt in. I think it is, but not positive. The stroker crank will be a direct fit. Running a HC piston depending on the compression can muddy the water. I did a 2mm stroker years ago in an 05 with a 13.5:1 piston and had no issues. If I were you, I'd contact the crank manufacture and where ever you get the cylinder and ask them for their reccommendation on piston compression. You will be increasing the stress on the bottom end significantly, so maintenance is going to have to be kept up. The cranks lifespan is usually hindered by the increased stress. If you're looking for something to drag race, the additional power is great, but if you're looking for something to just have fun on, leave it stock and have a blast on it. IMO, they're pleanty fast enough stock!

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