KFX 450 HQ Forum banner

1 - 20 of 52 Posts

·
Registered
Joined
·
67 Posts
Discussion Starter · #1 ·
69.8 on my Garmin Etrex Legend GPS after 2 runs wide open throttle.

My z400 did 73, raptor 700 is 78, my stock yfz450 was 76, my modified yfz450 with a 06 wr450 engine is 82, and predator 500 is 78. I dont really know any others.

I better not race any z400's down a long stretch, J/K

My new 15 tooth front gear will be in wednesday and ill post how well it works even though I think I need to go down 2 in the rear still on top of the 15 in the front.

Ill let you know.

Jeff
 

·
Registered
Joined
·
41 Posts
This quad was built for the trails not speed, this doen't suprise me.
 

·
Registered
Joined
·
15 Posts
That sounds more like the safety nazi's at work.

Does it feel slow to get there? are you bouncing off the limmiter in 5th.......I would not be suprised if Kawa electronicly limmited it to 70mph........

Linc
 

·
Registered
Joined
·
588 Posts
I'm reading it feels like it should have a 6th gear. That it accelerates very well and a gear change will do the trick.
 

·
Registered
Joined
·
67 Posts
Discussion Starter · #5 ·
It was kind of weird going down the road at wide open throttle and i didint hit the rev limiter, it just wouldnt go any more. A speed limiter would suck alot but I dont think I could understand it. If you change the gears, you should get more top end.

I was reading the info on there site, it seems like there are puching towards the race track. They said reverse was so you can get back on the track fast if you hit a barrier. And the aluminum frame and reverse is as light as just a steel frame and no reverse for the track. This machine has sick handling and sits 1 inch lower than my yfz on the seat and down low.

I know we are going to find a solution to the speed problem.

Jeff
 

·
Registered
Joined
·
81 Posts
Do you think the power commander will help that?
 

·
Registered
Joined
·
588 Posts
Unplug the exhaust, get a new air filter, remove the airbox lid and with the PC you'll be in good shape. FUELATV should be doing dyno test soon.
 

·
Registered
Joined
·
588 Posts
FUELATV will have an airbox eliminator kit similar to the LT-R. I'm sure K&N, ESR, FCI, and Ron Woods are all working on something for the KFX.
 

·
Registered
Joined
·
27 Posts
where can i order a front sproket at? went to the kawi dealer they didnt know anything
 

·
Registered
Joined
·
67 Posts
Discussion Starter · #13 ·
The front sprocket is a Moose Racing sprocket. Only maker to have one as I could see, but could be wrong. I had the part numbers but when I go pick mine up in a minute Ill Post the part number for you and the new top speed. Its a 15 tooth for a KX450F from parts unlimited.

Jeff
 

·
Registered
Joined
·
67 Posts
Discussion Starter · #14 ·
The top speed was 73.4 with the new front sprocket. The sprocket is the same sprocket for a YFZ450 and it also said KLX on the package. They double checked the numbers and its for a KX450F bike and the rest I mentioned above. Only problem is the sprocket spacing is a bit different on the KFX450R cause it has a 1/6th lip to make the sprocket stick out more so it doesnt hit the case. I rode around a while and everything is sound but I had to modify the front case saver to make the sprocket fit. Its too close for comfort in my eyes so I am not going to be running this sprocket for that long. I am going to get a new rear one probably a few with 5 or less teeth. Ill report how it goes when I get them.


I hate to say it but I am overly disapointed. This machine is corcked up and I dont know what to do without spending tons of money. Right now I am buying the Dynojet power commander and Ill see how well that helps. They ran out of trinity exhaust and air intakes so Im screwed from them for a while. I am also buying some cams and I hope by the time im done I wil be happy.

Other than that this machine has a lot of low end torque and power but when I got that new sprocket on, there was no top end at all. Ill see what I can do.

Jeff
 

·
Registered
Joined
·
160 Posts
Disappointed to hear the 15 tooth was shady. So now we wait for someone to make a rear sprocket for us? Going down a few teeth will require a link taken out..... ouch then you won't be able to switch back if you don't like it. :blink:
 

·
Registered
Joined
·
39 Posts
Disappointed to hear the 15 tooth was shady. So now we wait for someone to make a rear sprocket for us? Going down a few teeth will require a link taken out..... ouch then you won't be able to switch back if you don't like it. :blink:[/b]
you might have to just buy another chain for your other set up and then swap chains with sprockets...
 

·
Registered
Joined
·
15 Posts
Too plugged up to hit the rev limiter, I guess.[/b]
I would have to say it's got an electronic limiter. Your first run at a shade under 70MPH must be limited as with a bit of gearing the machine got an extra 4MPH.......that tells me at 70MPH we are not at terminal velocity; we have just run out of revs or it's limited. PCM says that when it gets up towards that speed it feels dead......that all sounds like electronic trickery.

The Power Commander will do wonders but I'm starting to think this is all ignition relaited. With the LTR we have the cherry bomb and that gives us a different fuel & ignition settings; with the KFX we dont have that option; a PC will only do fuel.

I suspect that to get the most out of a KFX you will have to buy the PC Fuel module and the Ignition module.......$700......but it will rip.

Linc
 

·
Registered
Joined
·
67 Posts
Discussion Starter · #18 ·
I got my rear sprocket off and I guarentee tomorrow I will find a cross reference for the rear sprocket. If not I have sprocket specialties to call and make one up but I dont like to wait.

I did some more riding around and it feels like the shifting is much better, I dont have to shift so much. And when I hit fith gear it really pulls hard.

I have 1 15 tooth front sprocket for sale. If anyone wants it for 17 dollars shipped let me know, I take paypal. I am keeping my 15 tooth front tho, cause I bought 2 in case. I dont recommend this 15 tooth cause it shady close by over a 1/4 of an inch and almost touching the case saver but its an immediate fix. The sprocket is from moose racing and its really nice.

I did some calculating and I figure I will at least need 4 teeth off my rear sprocket. That will equal out to a 34 tooth rear and I am also gonna buy a 33 and 32 just in case and I will let you all know the out come and what feels most comfortable.

I dont know if its corked up or if there is a speed limiter. I would most likely say its just geared wrong and has no top end since the gears are so short. As I gear it more, it feels more powerful and feels like top end is there.

There is a lnk in the chain so cutting it wont be so bad.

Ill let you know tomorrow what the outcome of the sprockets are.

Jeff
 

·
Registered
Joined
·
588 Posts
I would have to say it's got an electronic limiter. Your first run at a shade under 70MPH must be limited as with a bit of gearing the machine got an extra 4MPH.......that tells me at 70MPH we are not at terminal velocity; we have just run out of revs or it's limited. PCM says that when it gets up towards that speed it feels dead......that all sounds like electronic trickery.

The Power Commander will do wonders but I'm starting to thing this is all ignition relaited. With the LTR we have the cherry bomb and that gives us a different fuel & ignition settings; with the KFX we dont have that option; a PC will only do fuel.

I suspect that to get the most out of a KFX you will have to buy the PC Fuel module and the Ignition module.......$700......but it will rip.

Linc[/b]
Your probably correct the KFX has a dual stage rev limiter first at 10,500 & then 11,000 rpms.

Jeff keep up the great work.
 

·
Registered
Joined
·
5 Posts
hello everyone, im new to this site, you guys are doing a heck of a good job, someone keep me posted on the correct gearing for some more top speed, love the quad just bought it friday, thank you
 
1 - 20 of 52 Posts
Top