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Athena Big Bore kit for CFR450R

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Hi Guys, it's me again from Malta in need of some expertise!!:applause:

I am in the process of converting my 2002 CRF450R to supermoto, apart from wheels & brakes which come as excel/talon wheels, motomaster rotor & caliper & brembo master cylinder, I have fitted the usual trick bits.

But what's worrying me the most in the engine work, which I have the following so far (still to be fitted): Hotrods stage 2 cam, hotrods crank shaft, ported & gas flowed cylinder head, upgraded nuology spark plug lead, deep sump, power plus now & Dyno Jet for carburator.

I am also planning to fit a boyesen hi flow water impeller kit and have changed the rad hoses to silicon high performance ones.

My question is if I fit the Athena big bore kit, do I need to upgrade my radiators? If so any brand suggestions? I was going for the Fluidyne kit.

I was told I have to upgrade the valves & valve springs, which I'm going to do, but are the KIBBLEWHITE PERFORMANCE BLACK DIAMOND VALVES AND LIGHTWEIGHT RACING VALVE SPRING KIT up for the job? If not any suggestions will be highly appreciated!! :applause:

Thanks again to you all.

Best regards

Reuben

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If you leave the valves stock and use Ferrea springs and retainers you will have no problems with ANY cam I can think of. I've been using the Ferrea springs for 2.5 years now, roadracing, and have never had a failure. I'm redlining at 11,700. No beaten seats from valve bounce, no dropped valves ruining everything. I experienced all of these things, at great expense, with a couple of 'other' brands. Can't speak for the valves myself as I've not tried them, but the springs are the best.

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Hi tillertracker, thanks for the info, real appreciated, is your set-up on a CRF450?

Thanks again

Reuben

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Are you going to race this in supermoto? Stay stock springs and valves. A good increase will come with good head porting, cam timing, high compression ratio, balanced crank, and proper fuel/jetting. First ask your self how much power can you use and where do you want the power to be delivered. Then apply the right mechanical solution to your needs. I suggest just go with what you have now, race/practice a while and go from there.

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saw your post and figured i give my two cents even though im a yamaha guy. i got a wr450 supermoto as well. not as much work on it as you but got cams,pipe, new card and such and just got my athena big bore, 450 to a 480 and i had a few setbacks at the beginning. with my mechanic we discoverd that their blocks arent the best and their pistons arent the best either...i blew the bottom end out of mine after four days of not seriously opening it up. he had a friend in the midwest who drag race these bikes and have blown lots of them up so their solution was to rebore the athena and insert a steel sleeve in their and than use a wiseco piston.mine is 98mm and just got the bike back and it seriously kicks ass and im drag racing it in two weeks and it should haul some ass. so far so good but i do believe that these guys in the midwest do some very nice work, i saw the block before they put it in and it looked clean and the wiseco piston is wat better than the athena. let me know if you need anymore info.

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Hi supermoto49, I will take your advice and do those mods first. But can you please elaborate a bit more especially on the cam timing, high compression ratio & balanced crank. As I told you I'm quite new to supermoto and am still learning.

Thx

Reu

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