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Discussion Starter #1
Hey guys, I just bought an 08 KFX450R . Got a killer deal. 08 factory tires and grips still on it! 1800 !

Guy said it "has stage 2 cams in it"... Why would you add cams but have a stock exhaust?? Idiot....

Anyways, i rode it and it started cutting out at WOT. So i looked and the baffle was removed and has a K&N Velocity intake on it. So i knew he never got a fuel controller...

So i bought it, brought it home and looked it over. Went ahead and bought the factory airbox assemble and put it all back stock. Foam filter WITH lid ON.

I rode it and ran even worse? Took the airbox lid off, EVEN WORSE Lol.

Bought a FI controller... No change in any adjustments ive made???? Runs and pulls hard under 3/4 throttle! But no top end! :confused::confused:

So i decided to troubleshoot some more, so i started it and put my hand over the snorkel and revved it in Neutral and she revved good!! So its getting too much air. :D:D

Well, like i said, i tried to add more fuel VIA module to compensate for extra air but wasn't getting anywhere?? Like it didnt have any more adjustments left?? :huh::huh::confused::confused:

What i plan on doing is putting the velocity intake on (FCI knockoff) and turning module all the way up and going from there? IF itll work..

I know these bikes have fuel pump probs and TPS issues... but thats not my issue because i got it to rev by blocking off intake. Therefor running too lean.

As of now, Baffle removed, Factory airbox assembly on it , "supposedly stage 2 cams"... Guys If you could please help!! THANKS!!
 

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First off don't max the fuel controller. The velocity intake is good for a couple hp more than stock.

It sound a like maybe two things.

First off is a clogged strainer filter in the tank.

Order one and a new fuel pump off ebay. They are pretty cheap. There is write ups on this site on how to do it. Just do a search.

Second is tps might be out of adjustment. Buy the 20$ adapter and make sure it's set right.

Those two things should only cost 40 bucks and are more than likely the issues.
 

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Above recommendation^^^^^ ...!!!!

Also...!

Make sure the battery is fully charged...!! 12.8 volts standard

Does the F.I (far left) dash light remain ON when starting or motor running...??

Make sure the throttle cable has a little slack in it to prevent a DFI error & limp mode...
 

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Discussion Starter #4 (Edited)
I took the pump apart and noticed a it has been rebuilt before, filter was clean.. Like i thought.

The battery is good. Throttle cable is good. No. there is no engine light.
 

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I forgot about the battery too!

The fuel pressure might be low. You will have to check pump output. It needs to be a constant 43 psi.
 

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Discussion Starter #6
Update... I did all above, put it back together and took it down the road and it screamed like a beast for about 2 miles... then started its crap again.. ?? Air box lid on and off.
 

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Discussion Starter #7 (Edited)
I am trying to do the diag mode and i turn the key and FI light comes on for 2 seconds and cuts off like normal.. So i must not have any codes :)

I unplugged the IAT sensor then it started throwing a code. So i was doing it right. :) But yep. No engine codes
 

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What are your fuel settings? I don't think that's it just curious
 

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Discussion Starter #9 (Edited)
On my tuner there are 6 modes and it ranges from 0.5 - 8 (Higher # is injector duration obviously)

Low speed - 4
Mid Middle-6
High-6

(Fuel Timing) (accel. pump) Higher the number the longer it takes to give it the "shot"
Low timing - 6
medium timing -5
high timing-3
 

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Tune that top end to get no extra fuel at all. Most machines run rich at WOT even with full exhaust and FCI intakes. Try that and see what it does. Go all the way down until the light is flashing fast.
 

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Discussion Starter #12
When the bike cools down you can ride it and itll run good for about 2 miles then starts its crap. I literally put a wrap in the intake snorkel and it revved good while driving for like 3 miles, but i took it out so it wouldnt hurt anything Lol
 

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When the bike cools down you can ride it and itll run good for about 2 miles then starts its crap. I literally put a wrap in the intake snorkel and it revved good while driving for like 3 miles, but i took it out so it wouldnt hurt anything Lol
Only when thew motor warmed up does the problem shows...

Then check your valve lash/clearance if gap is too close will cause the valves to float above 1/2 throttle & difficulty to start...!!
Valve Clearance: between cam and valve lifter
Standard:
Exhaust 0.17 ∼ 0.22 mm (0.0067 ∼ 0.0087 in.)
Inlet 0.10 ∼ 0.15 mm (0.0039 ∼ 0.0059 in.)

If the valves are in spec's...!

Check your water temp sensor...! see pic

also you might what to do a fuel pressure test...43 psi especially around the RPMs it cuts out..
 

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Discussion Starter #14
Valves are in spec. Yall are literally just repeating yourself. But i will try a fuel pressure test.. and yes.. I just rode the thing a few min ago. When its cold is screams.. when it gets warm, it acts up. I can still cover the intake with my hand and itll rev clean in N. I can rev it in N with the lid on and off without my hand it spits and sputters. I even change setting on the FI tuner while holding throttle WOT. Nothing lol.
 

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Discussion Starter #15
When the bike cools down you can ride it and itll run good for about 2 miles then starts its crap. I literally put a wrap in the intake snorkel and it revved good while driving for like 3 miles, but i took it out so it wouldnt hurt anything Lol
Only when thew motor warmed up does the problem shows...

Then check your valve lash/clearance if gap is too close will cause the valves to float above 1/2 throttle & difficulty to start...!!
Valve Clearance: between cam and valve lifter
Standard:
Exhaust 0.17 ∼ 0.22 mm (0.0067 ∼ 0.0087 in.)
Inlet 0.10 ∼ 0.15 mm (0.0039 ∼ 0.0059 in.)

If the valves are in spec's...!

Check your water temp sensor...! see pic

also you might what to do a fuel pressure test...43 psi especially around the RPMs it cuts out..


Guy before me wired in a fan switch to manually cut it on. I pretty much leave it on the whole time im ridding. Engine does not throw any codes.

I still dont see how it would be a temp switch when i can manually make it run right by covering the intake lol
 

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Your getting too much air and not enough fuel then.
 

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Discussion Starter #17
EXACTLY.... Finally someone said Lol. But It has the stock intake on it = super restrictive lol.. But apparently not enough !

The FI module iv turned it up to max and Min and all between.. No change.. At all.
 

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Even with the stock intake with stock box opened up will need extra fuel. Is your box stock or lid modded or removed?
 

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Discussion Starter #19
I put the lid ON and still wont run right.. I have to have the lid sealed AND LITERALLY put my hand over the snorkel .. in theory giving it NO air. For it to rev clean... When its hot.. when the bike is cold it starts easy, runs and revs clean.. After a mile or so. It starts acting up..

Everyone said its the CTS. I dont see how though. No engine codes, No warning light, and fan is looked up to switch, i just ride with the fan on at all times just for the heck of it.

The coolant switch is still hooked up, and still reports to the ECU. The ECU just doesnt report to the fan.. But that doesnt matter. The ECU did its job and its past that stage of the process. It doesnt have to have a return signal.
 

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Discussion Starter #20
I guess i will just bite the bullet and buy a factory baffle and put it in the pipe. I still have stock exhaust. Then remove the FI controller. If it still acts up. then it may be an ECU issue.. because that would be the equivalent of an OEM brand new 100% factory bike.
 
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