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Engine Performance between a "X" and a "R"

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I finally got to ride a 250R this week and I can tell the difference in power between the 2...other than the Cam and Headpipe jetting and silencer what else will i need to go to get my X to perform like a R ?? Anyone one else try anthing?

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Y didn't you just purchase an "R"?? Would have been much cheaper in the long run. :cry:

I dont think so..........THe X has the open ratio tranny, electric start. headlight kickstand and a bigger gas tank....everything needed for trail riding..it would cost a lot more to add all that stuff on a R :cry:

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I dont think so..........THe X has the open ratio tranny, electric start. headlight kickstand and a bigger gas tank....everything needed for trail riding..it would cost a lot more to add all that stuff on a R

:cry: Well said :cry:

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My long winded reply on another post.

Most guys get the X and if the need more power they can choose many upgrade paths. Full CCC mods or partial, then add quicker steering and a update to the suspension.

We have raced our X with full CCC mods and updated suspension in our local off road series in the Expert class. It hangs well. Fast tracks with long drag race sections corner to corner are tough. The RMZ will pull us a bike or 2 every time. Gear spacing of the X requires us to give more attention to track layout and final drive gear. Problem is the cross country stuff needs the top speeds of the X. Even at 14/52 gearing we run it pinned in 5th alot then have to deal with MX type grass tracks. On those open sections Junior blows the RMZs away, so it is all a trade.

IMO the perfect cross country set up would be the R frame and suspension as a base. The 05 R motor (power between the 04 R and the 04X), a lighting coil with a tad of flywheel weight, 4th and 5th gear from the X or The X trans/primary drive with the "R" 1st and 2nd. A 3.4 gallon tank if someone made one.. The clarke 3 gal is ok for 2 - 2 1/2 events and 4 gallon IMS is just a tad bulky.

Well that is my dream.

Cam, Exhaust, Air box mods, Jetting. Gets you from 28 +/- 2 HP to 31-32 HP.

Get the air box as open as possible. May be another half pony.

Then the gearing. The primary drive ratio is different which changes final drive ratios and the gear spread.

Not sure if that primary ratio has an effect on clutch life. It may.

Ignition maping is the next big deal, the final pony can be found here.

Lighten the flywheel as much as possible to get quicker revs.

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I finally got to ride a 250R this week and I can tell the difference in power between the 2...other than the Cam and Headpipe jetting and silencer what else will i need to go to get my X to perform like a R ?? Anyone one else try anthing?

Bodyman's on it. The full CCC (full airbox mod, pink wire, etc.) will get you pretty close. Add the full R exhaust (or better) and the R flywheel and you're getting closer. If you really want to go full bore, the X and the R have different head part numbers for '05 (I'm not sure about '04), so if you swap heads, your performance will probably be as close as the weight difference will allow. I don't know what other power producing differences there would be.

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I would like to try a R airbox and a modified seat on the X. I believe the X is much more restrictive even when the top is cut out. With all the CCC mods the main is still 8 or more sizes less than a R.

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With all the CCC mods the main is still 8 or more sizes less than a R.

Is this info from dyno and A/F sensor data? The reason I ask is that I've jetted my '05 CCC X according to the '05 R jetting chart, and it seems pretty darned good. Exhaust outlet and plug are really nice in color, no blubbering. It really doesn't seem to be off by 8 sizes.......

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So what main did you end up with? I believe the stock R is 175 and I have ran as high as a 180. The CCC 04 has a 155, I think.

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So what main did you end up with? I believe the stock R is 175 and I have ran as high as a 180. The CCC 04 has a 155, I think.

I jetted according to the '05 R jetting chart at the bottom of Ramsey's jetting page. According to the chart, stock '05 main is a 172 which is good for about 70 degrees and sea level. At my altitude (5,000 ft), the recommended main jet is 170 for the same temps. That's what I'm running. I've tried as low as 165 and as high as 175, but the 170 seems best.

BTW, the 152 main is recommended for the '04 CCC mods. However, a little further up on the Ramsey's page is the '04 R jetting chart which indicates that a 155 was the stock main jet for the '04 R. The difference between the recommended '04 CCC X jetting and the '04 R jetting indicates that there is a slight difference between the two, but not much. I'm not sure why Honda changed the recommended main jet size so drastically for the R between '04 and '05, but the '04 chart seems lean all the way around.

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skipn8r wrote:

I'm not sure why Honda changed the recommended main jet size so drastically for the R between '04 and '05, but the '04 chart seems lean all the way around.

--------------------------------------------------

The following parts are different between the two years:

float bowl

accelerator pump diaphragm

fuel screw

needle

main jet

pilot jet

As you note, the '04 jetting chart is leaner than the '05, and I suspect the main culprits are the fuel screw and needle, which then may necessitate a larger main jet and fatter clip and fuel screw settings.

Just whistling in the dark here :)

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I've gone from an 04 r to a 04 x. Full ccmods including cam and r complete exhaust. Pilot jet 42 main 162 needle standard 1.5 turns out on air screw. Bike rips with 14/53 gearing. The only real differance I can pick is that where the r snaped out of corners with the rear breaking traction the x bites and drives out of the corners. Speed at the next corner ends up about the same, just gets there a different way. The R is definatly quicker but more to the way of snappier, eg close ratio g/box flywheel. The x works better in the bush and less tiring and quicker to ride. Granted there are times the snap of the r would be nice and I think if I can find a s/h r flywheel I will try that to get it. All that with a wide ratio tranny and it will be as nice as the r

0 to 1000 feet 20-34 deg c

Cheers :)

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As for jetting in 05, I think honda fattened the jetting many because that is what everyone did with the 04.

The X may always be a main jet size or 2 lower on the main and a HP short of the R since the Air Box restriction cannot be overcome unless you remove the wiring/electrics and carve away.

Our X with full CCC mods and a way open air box (more than I wanted, wet races need baffling) with U4 or pump fuel at sea level to 1000ft can run a 165 - 170 main. Normal race fuel like C12 we find a 160 works well most of the time..

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