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Discussion Starter · #1 ·
Ok, had a chance to make a few runs.

Raced a 2007 Honda 450r with a pipe and a stock Renagage

Ran each twice on black top with a small up hill grade.

450r left me pretty easily both runs. :(

Renagage (800 can-am) I held barely even in the 2 runs :crazy:


I think my KFX has the power, the gearing just seems to be too low. Might see if I can find a smaller rear sproket. I'm running in 4th and 3rd gear on the KFX where I was doing 3rd or 2nd on my TRX.

And another note, bar inserts fixed the bar vibrations.
 

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Discussion Starter · #3 ·
I think the power is there but it geared too low. A pipe, K&N, with a programmer....and a sproket change. I think the KFX will be really fast.

The down side...thats almost $1000.00 to make it fast.

Don't get me wrong, I love the bike so far!!!!!!but I do like my stuff to be faster than everyone else.
 

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I noticed the gearing myself and others have posted about it here. Once it gets up top you are moving but getting there takes too long.

I am, looking forward to a pipe and a controller. I am hopeful that will help get through the bottom end quicker. Only time will tell.
 

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Ok. BunkerHill is saying its geared too low, better acceleration with less top speed. Raredirt is saying the opposite, slow acceleration high top speed. Which one is it.
 

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Bottom line is that 5th is geared low compaired to other bikes. I found myself in 5th looking for 6th. This bike is corked up.I think pulling the air box lid, removing the baffle and adding a PC will make a HUGE difference.



FUELATV
 

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I can beat a modded honda 450r almost every time in a 300ft race but anything after that and BYE BYE honda. I can stay about 2 bike lengths ahead of a modded KFX 700 from start to top out. I have yet to race my buddies 700 rappy in a 300ft race.
Later
 

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I can beat a modded honda 450r almost every time in a 300ft race but anything after that and BYE BYE honda. I can stay about 2 bike lengths ahead of a modded KFX 700 from start to top out. I have yet to race my buddies 700 rappy in a 300ft race.
Later[/b]

Would love to hear the race against the Rappy.
 

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The top speed of the KFX450r is 69.8 on my Garmon Etrex Legend. I posted tha on a different site a few days ago. It is geared way too low. Its like my YFZ450 with the wr450 motor in it. Once I geared it down with a 13 front gear on the yfz it has alot of power but you are shifting alot and tops out in the low 70's while with the 14 tooth front sprocket its is a bit harder to take off and the gears are taller it feels like. It goes faster and has a hard hit.

My sprockets will be in wednesday for our kfx450's. I ordered 2 15 tooth front sprockets thru moose racing for 16.95 each. I cant guarantee they will fit since they were from the dirt bike. I know the chains gonna be close to the case too. Well see. But as for drag racing, its worthless cause its geared wrong.

Once im in the next gear i feel like i have to shift again. I know it needs to be uncorked and some changes but the hp is there. Its just geared for the way i need it.

Ill let you know wednseday exactly how fast and fitment for the sprocket.

Jeff
 

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The top speed of the KFX450r is 69.8 on my Garmon Etrex Legend. I posted tha on a different site a few days ago. It is geared way too low. Its like my YFZ450 with the wr450 motor in it. Once I geared it down with a 13 front gear on the yfz it has alot of power but you are shifting alot and tops out in the low 70's while with the 14 tooth front sprocket its is a bit harder to take off and the gears are taller it feels like. It goes faster and has a hard hit.

My sprockets will be in wednesday for our kfx450's. I ordered 2 15 tooth front sprockets thru moose racing for 16.95 each. I cant guarantee they will fit since they were from the dirt bike. I know the chains gonna be close to the case too. Well see. But as for drag racing, its worthless cause its geared wrong.

Once im in the next gear i feel like i have to shift again. I know it needs to be uncorked and some changes but the hp is there. Its just geared for the way i need it.

Ill let you know wednseday exactly how fast and fitment for the sprocket.

Jeff[/b]
Jeff, Sounds great look forward to hear about this. Also, welcome to the site...
 

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woops, I meant the gearing on the stock kfx450r is not how i need it, thats why I am buying those gears. I also ordered PRM skids and ill let everyone know how those fit and stuff. Not that it matters too much.

Ill be ordering the crower cam pretty soon and Ill let you know how that goes.
Jeff
 

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Discussion Starter · #12 ·
Thnak you Jeff.
I will be looking to hear about the gearing change. I was thinking about going smaller on the rear but kind of like your saying, its hard to find parts yet. That top speed your hitting is balls out too. so even to hold 55-60, your reving pretty high. My bar inserts really fixed the buzz in the bar at those speeds....

PRM skids are showing up this Friday for me. I'll post pics once in.
Trailtech Vapor and mount will be in soon. too. Had some kind of Chrome plating issue holding up the mount. Then I can watch RPM and speed.....
 

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When I first got the KFX I went out side up to the road with about 10 minutes on the machine and went balls to the wall down the road 2 times as fast as I could going slightly downhill. One hell of a wat to beak it in, lol. I taped the GPS to the middle part of the bars and it records your overall top speed of your runs. So the first run I could have went 68 mph and then the second run 69.8, it would then record the faster of the 2 times and thats what I got. So far I have like an hour on the machine maybe an hour and a half.

My skids come in friday too. I had to pay extra for shipping today or else i wouldnt get them till next week.

What has anyone done to raise the handlebars? Are these bars bigger than the yfz bars? reason I ask is cause im 6 foot and i have to lean forward to reach the bars and my 5 foot 6 brother doesnt have too.

I bet the 15 tooth sprocket is either A not going to make the machine fast enough or B it will come too close to the engine case for comfort. I will measure the rear sprocket and see if I can find something universal.

I was looking around for a sprocket laying arounf and I had one from my YFZ and one from the predator 500, and they both fit on the kfx but the spacing is a hair off. Kinda odd, i thought they were all different.

Jeff
 

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Quads get a little faster as they break in. A bike with 10 minutes on it is not a good candidate for a top speed rating. Its also very hard on the engine due to the close tolerances they are assembled at. If I were you I would lay off the wide open throttle for extended periods until I got it a little more broken in. But thats just me. Do what you like.
 

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Yeah i agree 100%.
 

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Discussion Starter · #17 ·
There was a note in the manual, Break it in or it will break down.

I put on about 50-60 miles of trail riding before givin' her hell :)
 

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Quads get faster as they break in? I dont think so. I dont think im going to gain a single MPH till I change the gearing. You can break yours in like a girl and Ill break mine in the right way, Hard. But thats just me. Just for your sake of BS, ill put some more time on the machine tonight and do another run for you and post the tops speed.

I dont see why anyone would disagree, I got the bike, I did 2 runs and I got a top speed,WOT down the road pinned. I guess if I want to blow the motor up I can hold it for another minute and maybe squeeze 70 if you want. Its just not a fast 4wheeler, its geared that way.

Jeff
 

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Quads get faster as they break in? I dont think so. I dont think im going to gain a single MPH till I change the gearing. You can break yours in like a girl and Ill break mine in the right way, Hard. But thats just me. Just for your sake of BS, ill put some more time on the machine tonight and do another run for you and post the tops speed.

I dont see why anyone would disagree, I got the bike, I did 2 runs and I got a top speed,WOT down the road pinned. I guess if I want to blow the motor up I can hold it for another minute and maybe squeeze 70 if you want. Its just not a fast 4wheeler, its geared that way.

Jeff[/b]
You dont have to get anal about it. You are right, it is yours and as I said at the end of my post do what you like. And to break one in takes a little longer that 15 minutes around your yard. I am speaking from my own experience about one getting a little faster as they break in. Im not saying you will gain 10 MPH or even 5. Spend a little time on it(a week or so), let it free up some, do another run or 2, if it doesnt gain 1 or 2 MPH then I will appoligize for my BS....
 

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It wont blow up with a hard break in it just might have things wear out a little sooner, like rings and bearings ect but either way no big deal since most people rebuild before then anyways but one thing that you have to keep in mind is that the breaks and clutch need to be broken in as well other wise you could get chatter and and you breaks will bed in poorly. Other then that just make sure to change your oil after a few hours and you should be fine.
 
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