[corey420]

recently purchased the athena big bore kit to replace my tired piston and cylinder. waitting on the head to be finished. before i can ride. just wanted to know what you guys think or thought of it. thanks!

[crfsonly]

it's an excellent big bore kit. quality components that comes with a new cylinder with larger water jackets to keep the motor running within designed temperature range. it's the correct way to do a big bore.

ken

[[email protected]]

I love mine!

[T-Bone68]

I know this is an old post. My 2005 CRF250X was rebuilt before just before I bought it. It has cylinder works std. bore kit, hot rods standard crank. FMF megabomb and Q4. I was told a simple valve job was done on the stock X head. Hot cams stage 1. Air box opened up per CCC bulletin, and pink wire disconnected JD jet kit. It runs really great, no complaints at all riding the trails I ride. My only issue is this- I have the bike registered for the street, mostly to get to and connect trails. With the 5 speed it's annoying to ride around town. At 50 mph I'm over 7000 rpms with 14/52 gearing. I tried as high as 14/48 and still not quite tall enough for some of the roads at 50-55, but in the woods seemed too tall. So I was thinking of getting an Athena 280 kit to get some more grunt and try gearing even a little taller, possibly 14/45. Is this a logical endeavor? Would my stage one cam be suitable, or would it be necessary to go with an R cam and head? Or leave my cam and just get an R head. I'm not looking for a screaming top end, but don't want to turn it into a tractor that falls flat at 7500 rpms.