kfx450r a "maitenance nightmare"

[Duster]

Now some guys have had zero electrical problems and 100% good experience.

But if you buy a used one, I'd say the chances are high that you are buying a buggy trade-in. But I can guide you through any troubles.

My advice for good KFX450R service is...

Download factory service manual from internet (free)
Buy 2 multimeters, 1 digital autoranging, 1 analog
($45 for both at Sears or Walmart)
Unhook every connector and put in dielectric grease.
Buy the throttle sensor setting adapter and hook it up inline
Use digital multimeter to check TPS periodically
Never install higher rated fuse in place of a blown fuse... find the problem
Exercise common sense if you use pressure washers

Use very robust synthetic oil... change when it looks dirty in sight glass
(15w50 Mobil 1 in summer, 10w40 Mobil 1 motorcycle in winter... or Amsoil equivalent)
Service air filter religiously when needed.
Don't use K&N filters unless covered with outerwear and used in desert (large particulates)
Disassemble and grease suspension pivot points periodically
Don't install fancy lightweight sprockets ever
Check chain slack and sprocket bolts regularly
Buy a Moose Poly case saver in case anything ever goes wrong with the chain
Put good skids under the aluminum frame

Remember this EFI system has no ability to adjust for mods

[NHRider]

Thanks duster you have been alot of help. But when you say "Disassemble and grease suspension pivot points periodically" how often do you mean .. once a year?, every ride? And also when I buy the used one (hopefully soon) im going to bring it to a dealer, so I assume they can tell me if it has any electrical problems right? After having it for some time I plan on putting on an aftermarket exhaust (slip on or full system... just not sure yet) but if I do then do I need some sort of programmer because I mentioned it to a kawasaki dealer and they said that the EFI would adjust. They said only if you seriously mod it then it would be needed. What would happen if I put on an exhaust without a programmer?

[Duster]

Originally Posted by NHRider

Thanks duster you have been alot of help. But when you say "Disassemble and grease suspension pivot points periodically" how often do you mean .. once a year?, every ride? And also when I buy the used one (hopefully soon) im going to bring it to a dealer, so I assume they can tell me if it has any electrical problems right? After having it for some time I plan on putting on an aftermarket exhaust (slip on or full system... just not sure yet) but if I do then do I need some sort of programmer because I mentioned it to a kawasaki dealer and they said that the EFI would adjust. They said only if you seriously mod it then it would be needed. What would happen if I put on an exhaust without a programmer?

A lot of guys just take this stuff apart when they get a machine home, even new. Some claim the factory doesn't put enough in the pivots and rear axle carrier. I haven't bothered with it myself. Over the winter probably wouldn't hurt in my opinion.

Some dealers can help you with these... most can't.
Mine couldn't help me although they tried very hard.
So I learned how to help myself.

I can help you with most anything you run into.
Electrical stuff has a reputation of hiding, and then showing up later at random.
Don't worry... save your money... and just ask me if something pops up.
I'll teach you how to find and fix problems if you have any.
(I know what it was like to be on my own with it)


After having it a while, put a full system on it like I have.
They are big bucks direct, but I can show you where to get one for $365.

The stock titanium header is a nice buzz word for sales... but it cracks. So for a few more dollars than a slip on you can avoid that replacement cost down the road... cause you'll have to buy another stocker to keep using your slip on... So for a few dollars more you avoid that and gain the performance of a full exhaust.

Certainly don't take your KFX to that dealer's shop. They are clueless. The KFX does not have any ability to self-adjust for mods. It has no o2 sensor, or mass air sensor. In stock form all it can do is try to compensate for air temp (inlet air temp sensor) and altitude (inlet air pressure sensor).

Most people have been able to add an exhaust system without any problems though. But not because the KFX can adjust... but because the stock mapping is RICH in most cases.

So an exhaust without a programmer just brings the air/fuel ratio closer to spot on.

I would not buy a programmer for a while until you see how good everything is... which means you won't be able to change intakes... but you won't need the programmer until then anyways.

[ayovan]

Once again....your dealer is full of crap. the EFI on these quads do NOT self adjust. To self adjust there would need to be a wide band 02 sensor and the EFI would need to have the capability to compensate, which it does not. Just to do an exhaust you would not need a programmer. The stock EFI is set a little on the rich side so you would be ok, but you would see little to no gain from doing a slip-on or a full pipe only. If you did an aftermarket intake you would need a programmer since the new intake would flow so much more air into the engine you would be running lean. The intake is where you will find a huge gain in performance. With an intake, programmer, and a pipe (the "Big 3") you will get about as much performance from the quad as you can with just bolt on parts. I dunno why you keep talking to the dealer. Obviously he doesn't know jack.

[NHRider]

Originally Posted by ayovan

Once again....your dealer is full of crap. the EFI on these quads do NOT self adjust. To self adjust there would need to be a wide band 02 sensor and the EFI would need to have the capability to compensate, which it does not. Just to do an exhaust you would not need a programmer. The stock EFI is set a little on the rich side so you would be ok, but you would see little to no gain from doing a slip-on or a full pipe only. If you did an aftermarket intake you would need a programmer since the new intake would flow so much more air into the engine you would be running lean. The intake is where you will find a huge gain in performance. With an intake, programmer, and a pipe (the "Big 3") you will get about as much performance from the quad as you can with just bolt on parts. I dunno why you keep talking to the dealer. Obviously he doesn't know jack.

I have not gone back to that dealer ever, the ones I am talking to are different deales because the first one didnt seem to no anything. There are a bunch of dealers around me but the one that didn't seem to know anything is far away from me. I only talked to him once and he was the one that said all that stuff about the 450s. There were two DIFFERENT dealers that said you would be fine with a pipe on it. My mistake because they said you would be fine with just a pipe on it. I thought they said it adjusted, so if you add more than a pipe then you would need a programmer.

[ayovan]

Let me correct myself. The EFI will make small adjustments for temp, and altitude as Duster said

[Sledneck253]

Originally Posted by NHRider

I plan on buying used because I dont have the money to buy new so it won't have any warranty. On my quad now I do the oil, chain and airfilters regulary. I like to keep them running and looking nice but like I said before I don't want to have this so called "race engine" and have to tear into the motor for different things (simply because I dont know how). I want a bike that rips on trails but if what some of these service departments are telling me is true then why take the chance and end up sinking tons of money into maintaining the thing. It seems like you agree with ayovan about the amount of maitenence? and if/when I get this quad I can do normal maitenance but maybe a little more often and it should be fine?

I loved riding my kfx 450. But it's waaay slower than any other 450 and after 3 years of constantly fixing electrical gremlins and buying expensive parts that wouldn't fix my problems I gave up on it. I would say don't buy a used one!!! I had to use my warranty all the way till it expired. Maybe I bought a lemon first year, that's jmo. If I could go back in time I would have bought the ltr 450

[Duster]

If you still have it I can help you figure out what is really wrong with it.

Despite all the hype and arguing and so forth, if you run all of the 450's back to back on the same dyno, they are all within 2 hp of each other stock. And if you run the same units on the same dyno the next day, again they will all run within 2 hp of each other, but they may swap up on bragging order. Same goes if you look at a dyno of a different set of units.

Point being they are all very close when running correctly... and the dynos are really not accurate enough down to that degree to give a definite answer which one has more power.


Out in the real world riding with buddies and such though, it is really hard to find an LTR that doesn't at least have the intake & exhaust opened and a cherry bomb installed... cause the investment is what... a few minutes and $40 for a big gain over stock... like 7hp or something...

That's really hard to compete with on the KFX with it's short stock gearing and all.
You have to do a sprocket gearing change and some mods also to keep up with an LTR.

[NHRider]

It's either I buy used or don't get anything at all, so I will take my chances. I wont be buying an ltr because it is so wide and doesn't have reverse. I know there are kits to make it narrower but I dont want to go through all the trouble. I want to bring it to a mechanic so they can tell me if there is any thing wrong with it.

[Duster]

Originally Posted by NHRider

It's either I buy used or don't get anything at all, so I will take my chances. I wont be buying an ltr because it is so wide and doesn't have reverse. I know there are kits to make it narrower but I dont want to go through all the trouble. I want to bring it to a mechanic so they can tell me if there is any thing wrong with it.

Right... I love the LTR and if they made an XC version with reverse I'd be on one.

Before new quad prices started taking a nose dive, I actually committed to buy a new LTR. At the time the Suzuki dealer with a bunch of stock folded... and their dealership + inventory was transferred down the street.

I had a chance to buy one new for $4799, which AT THE TIME was a steal. So I was willing to give up the reverse for that... and spend some of the savings narrowing it. Filled out the paperwork close to 5pm... then had to plan to return at lunch the next day to finalize everything... which I did.

Long story short, the sales MGR sold it out from under me and his sales person about an hour prior. A year or so later a guy bought a place for sale 4 houses down from me, and we were talking and it turns out he's the one who ended up with my LTR. Small world.

It's an awesome machine... sick on logging roads, fire roads, etc... But he won't go with me back in the woods anymore. He has a hard time keeping up with the width, and got tired of getting hung up and having to get off and push it back.

49" is a nice width, but it gets really wide back in the tight woods.
It's great otherwise.