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Lighten Flywheel

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Hellow, can anyone tell me where to have my flywheel lightened and balanced for a XR650R? I did a search but could not find anything. Rob Barnum did my last one, but i bought a Vortex adjustable ignition and when they welded the longer pickup on the flywheel they demagnatized it so i need the new one lightened. I cannot find Barnums pro products. Thanks Ted

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if you dont mined me asking, why do you want it lighter? 

It gave it a bit more snap, also supposed to work well with the vortex ignition.

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hi, ive lightened mine, the std rotor has two 10mm holes, ive bored these out to 16mm, then i drilled the other 4 blank holes[ i.e. not drilled] to 12.5mm, this difference is nessesary to maintain the crank balance, i have a xr400 cdi that allows 9000 rpm, as well as 2mm ov/size piston, and falicon rod, with this mod its as smooth as with std size piston

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i have a xr400 cdi that allows 9000 rpm

xr400 cdi works wit a 650R?

or are u judt pointing out how u have an improvement with a bike with a lightened flywheel...?

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Thank you for the replies so far, mine was alot more fun to ride with the lighter flywheel, it was easier to get the front end up for going over logs if theres traction I went overboard with modifications and now that im getting older i really like the way the stock just uncorked 650r runs right off idle.Im working on a friends stock just uncorked 650r that he left fuel in for 2 yrs, what a mess, Sold him my stock carb and a uni filter for 65 dollars and it runs like new again.Waiting for the fuel petcock to comein to finish it. His has hardly no miles on it and looks like it juust came from the factory. Mine is in very nice shape also but i have it plated,Mikuni TM40 carb, full hrc kit with 3mm oversized intakes stock sized exhaust stainless valves with kibble white springs and retainers. Also had the head mildly ported? at louthan cylinder heads in Oregon. Vortex ignition,bat wing and opened up side cover and the compression release removed from the hrc cam, and a morwaki full exhaust. Its real fast compared to the stock un corked bike but where am i going to use it in Illinois.I was worried about the big valves and kibble white springs without a hardened cam an rockers but its been over 5000 miles and the valves havent moved at all. I am going to call a few machine shops and see if they can shave that flywheel for me. Also if anyone needs a stock triple clamps, full stock exhaust, like new stock head light, cdi box and misc stock parts let me know. Thanks again Ted

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xr400 cdi works wit a 650R?

or are u judt pointing out how u have an improvement with a bike with a lightened flywheel...?

the 96 model ign works better on the 650r as it has slightly different timing,and allows more revs, which is probably only useful with a modified mtr

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Thank you for the replies so far, mine was alot more fun to ride with the lighter flywheel, it was easier to get the front end up for going over logs if theres traction I went overboard with modifications and now that im getting older i really like the way the stock just uncorked 650r runs right off idle.Im working on a friends stock just uncorked 650r that he left fuel in for 2 yrs, what a mess, Sold him my stock carb and a uni filter for 65 dollars and it runs like new again.Waiting for the fuel petcock to comein to finish it. His has hardly no miles on it and looks like it juust came from the factory. Mine is in very nice shape also but i have it plated,Mikuni TM40 carb, full hrc kit with 3mm oversized intakes stock sized exhaust stainless valves with kibble white springs and retainers. Also had the head mildly ported? at louthan cylinder heads in Oregon. Vortex ignition,bat wing and opened up side cover and the compression release removed from the hrc cam, and a morwaki full exhaust. Its real fast compared to the stock un corked bike but where am i going to use it in Illinois.I was worried about the big valves and kibble white springs without a hardened cam an rockers but its been over 5000 miles and the valves havent moved at all. I am going to call a few machine shops and see if they can shave that flywheel for me. Also if anyone needs a stock triple clamps, full stock exhaust, like new stock head light, cdi box and misc stock parts let me know. Thanks again Ted

i hear what your saying about the h/duty kibblewhite springs, i ran my hrc copy cam without their springs, i just used their light weight retainers with their ov/size valve kit

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the 96 model ign works better on the 650r as it has slightly different timing,and allows more revs, which is probably only useful with a modified mtr

well thats interesting iv heard of guys running 250-400 cdi's in XR6's but not a 650R i figured the motor was too different and would not work.

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well thats interesting iv heard of guys running 250-400 cdi's in XR6's but not a 650R i figured the motor was too different and would not work.

Really?  I wouldn't mind rocking a 250 cdi, my XL600 is all cammed out with a ported head, probably wouldn't mind spinning a few extra RPMs, that and I could actually buy a new one since the original CDI is NLA.

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Really?  I wouldn't mind rocking a 250 cdi, my XL600 is all cammed out with a ported head, probably wouldn't mind spinning a few extra RPMs, that and I could actually buy a new one since the original CDI is NLA.

i have read u can do this yes, but i don't think its plug and play.

another thing iv heard is when an XR6 spins above 8,000RPM they can suffer valve float so if u intend on doing this id do some more research and run heavy valve springs.

from memory:

XR6 8,000RPM limiter

XR4 10,000RPM limiter

XR2 23,000RPM limiter

im also fairly sure the 250/400 cdi's have a sharper power curve/timing advance

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i have read u can do this yes, but i don't think its plug and play.

another thing iv heard is when an XR6 spins above 8,000RPM they can suffer valve float so if u intend on doing this id do some more research and run heavy valve springs.

from memory:

XR6 8,000RPM limiter

XR4 10,000RPM limiter

XR2 23,000RPM limiter

im also fairly sure the 250/400 cdi's have a sharper power curve/timing advance

I have stiffer valve springs installed, but I don't know if I can do any more timing advance.  This motor already has a affinity for race gas as is...

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I have stiffer valve springs installed, but I don't know if I can do any more timing advance.  This motor already has a affinity for race gas as is...

worst case scenario file the top of the piston to decrease compression lol but in all honesty i don't see much if any value in the higher rev limit unless your pig has been designed to rev (cam, valves, ports, carb, flywheel) as most are well past peak power by the time they hit full revs  

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hi, ive lightened mine, the std rotor has two 10mm holes, ive bored these out to 16mm, then i drilled the other 4 blank holes[ i.e. not drilled] to 12.5mm, this difference is nessesary to maintain the crank balance, i have a xr400 cdi that allows 9000 rpm, as well as 2mm ov/size piston, and falicon rod, with this mod its as smooth as with std size piston

Hellow, did you weigh it before and after you drilled the holes? Thanks Ted

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