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my fmx 650...

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it has the xr650l engine without any changes...

stock it dynoed at 30 at the wheel on a superflow dyno which is a bit tight comparing with a dynojet 250...i put a full arrow exhaust, a dna filter with some air box cutting and a tm40-6 mikuni...it went up to 37...

a month ago i put the head on my bench did some work and got a 11/1 je 101mm and a hotcams stage 1...

it went to 46 but it died badly after that as it used to do before, ending at 30 at the limiter...

i believed the problem was at the exhaust,so i designed a full system and fabricated it at a local guy who did exactly as told and made a good piece...i also used a ti-force carbon can...without any fuel changes it went 50 and kept 44 at the limiter...13 up from before...

i'll tune it shortly and let you know...for the time being it's been fun...👍

this is the arrow...

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1793162_2_b.jpg

this is my custom one...

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and this is a comparison with the four dyno sessions i mentioned...

sygkritiko2.jpg

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Cool............i have a fifth gear coming for my XR650L that`s in the FMX and NX650....it`s taller than the OE gear in the XR650L...

What did you do to the head........you could also stand to gain even more HP with a MegaCycle cam in one of the race grinds..

B

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Cool............i have a fifth gear coming for my XR650L that`s in the FMX and NX650....it`s taller than the OE gear in the XR650L...

What did you do to the head........you could also stand to gain even more HP with a MegaCycle cam in one of the race grinds..

B

with stock final drive which is 14-42 goes up to 180 real km/h on the limiter which is fine...

the head...blended the seats which were horrible to say the least,thined the divider as much as possible keeping in mind not to overdo due to temperatures,straightened the floors and sides and hightened the seilings a bit...much work went on the exhaust side regarding straightening the floors...

you're right about the mega cams,but i use the bike daily in town for at least 30 km and many times the traffic is huge...wanted to keep it almost stock reliable and the budget as low as possible...

maybe later i'll turn it into a monster...i don't know yet...👍

i also got an oil cooler...when i got the time i 'll put it in...have to do some work on a customers xr650r first ,and then comes a busa for big bore...

a couple of head pics...didn't have time for more or better...

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and a couple of the cooler...

22082011327600x337.jpg

22082011326600x337.jpg

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Cool............i have a fifth gear coming for my XR650L that`s in the FMX and NX650....it`s taller than the OE gear in the XR650L...

What did you do to the head........you could also stand to gain even more HP with a MegaCycle cam in one of the race grinds..

B

will the taller gear also fit a XR600r 1994 or a 97?

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Wow that dyno chart is awesome! Incredible numbers! What was difference in air temp, barometer, & humidity? (on the different runs)

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apart from the stock one,which isn't mine and was used for referance,the three others were almost identical regarding chamber temperatures...23-25 C..pressure an humidity didn't bother to check...

motor has 500 km after the built so i'll wait for another 500 ,final tune it and share the results...

probably retard the cam a bit...we'll see..

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will the taller gear also fit a XR600r 1994 or a 97?

Not sure on that,,i know the countershaft is the same,except the XR600R has the end machined for the kickstarter idler gear,,,just not sure as the new fifth goes on the mainshaft..

B

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Looks like there is a lot more room for porting on the intake side. XR's Only certainly takes a lot more material out after looking at the head on my 600. I wouldn't put any more time into the exhaust ports; they flow plenty even as-cast. The individual ports aren't just to snake the exhaust around a frame tube...

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It's great that mods on the 600s and 650Ls tend to increase power across the entire RPM range, not just at the upper revs.

Do you know the correlation on that graph of RPM to Km/h?

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It would be easy to figure out if we knew the tire size, final drive ratio, and which gear it was in during the dyno runs. I could make a bunch of assumptions based on information I found online, but they're only assumptions. Stock power figures are quoted between 5400 and 5800rpm(I would say 5500-5600 is accurate; that's where the 650L peaks and both engines make the same output), so it looks like the modified engine was peaking 500-1000rpm higher than that.

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It would be great to see a Torque/HP X RPM graph with the correction factor, air temp, humidity, barometric pressure and altitude for each run.

It looks like great increase. 👍

To make an accurate comparison of the different dyno runs the graphs for each run with the above info would be needed. :worthy:

I wish we could buy an FMX650 in the USA. :worthy:

:ride:

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unfortunately i don't have the details for the runs...just got a printout of the comparison...

if i remember correctly k sae factor was between 0.999 and 0.992 in all runs and air temperature between 23-27 celcium and humidity at 65-75%...sea level...

i believe a have another printout of the second best run with rpm/hp...if i find it i'll post...i think best torque was at 5.9 kg...not sure though...

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unfortunately i don't have the details for the runs...just got a printout of the comparison...

if i remember correctly k sae factor was between 0.999 and 0.992 in all runs and air temperature between 23-27 celcium and humidity at 65-75%...sea level...

i believe a have another printout of the second best run with rpm/hp...if i find it i'll post...i think best torque was at 5.9 kg...not sure though...

That would be 43 foot pounds of torque if I figured it right.... :worthy:

RPM/HP would be great, I can figure out the torque curve from that. :worthy:

Thanks. 👍

:ride:

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Cool............i have a fifth gear coming for my XR650L that`s in the FMX and NX650....it`s taller than the OE gear in the XR650L...

What did you do to the head........you could also stand to gain even more HP with a MegaCycle cam in one of the race grinds..

B

how and where are you getting the taller 5th? i want one too!

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That would be 43 foot pounds of torque if I figured it right.... :worthy:

RPM/HP would be great, I can figure out the torque curve from that. :worthy:

Thanks. 👍

:ride:

got it...only bad thing is that the guy started it from 4500 rpms...anyway...

first one hp/rpm,second one torque/rpm...this is the dyno with the arrow...second best on the compare runs...

arrow.jpg

arrowtorque.jpg

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am i the only one that clicked on the link because i thought some idiot set up his xr650 as a freestyle motocross bike?

Awesome looking super moto. and even better looking numbers.

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am i the only one that clicked on the link because i thought some idiot set up his xr650 as a freestyle motocross bike?

Awesome looking super moto. and even better looking numbers.

LOL i did too, that woulda been hilarious seeing a freestyle tank

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LOL i did too, that woulda been hilarious seeing a freestyle tank

The landings... brutal:lol:

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