Valve train reliability issues with 520?

Joined
Aug 13, 2000
Messages
826
Likes
5
#1
I am due for a newer bike, and I seem to remember Eric mentioning that the KTM RFS bikes had valve train issues. Could those in the know please fill me in on the problems and the fixes.

TIA,

Chris
 

SFO

Lifetime Sponsor
Joined
Feb 16, 2001
Messages
2,001
Likes
0
#2
Most of the major valve train issues I have been seeing revolve around the SX series of RFS bikes.

The inverted flank cam which was adopted from Husaberg is equally destructive in that engine too, due to its ramp speeds.

 

The ex-c/mx-c motors get a kinder gentler cam.
 

kev_rm

Subscriber
Joined
Jun 7, 2002
Messages
196
Likes
0
#3
Bad batch of cam bearings and a problematic auto decompressor nut in 2000,2001. New bearings and an updated nut&wheel for the auto decomp and you should be set.
 

Shaw520

Damn Yankees
Joined
May 14, 2000
Messages
1,082
Likes
5
#4
Originally posted by SFO
Most of the major valve train issues I have been seeing revolve around the SX series of RFS bikes. 
 
  

 
Geeze,...guess I better stay outta my garage, cause I got three in there that should be getting ready to grenade any day,...... :silly:

 
 

Shaw520

Damn Yankees
Joined
May 14, 2000
Messages
1,082
Likes
5
#5
Cujet, I know this is a sure way to start a debate, and one that has run its course through these pages many times before, but let me just say that what you hear on the internet is basically the worst of the worst.

Between myself and my riding buds, we have, or have had, no less than eight RFS's ranging from the original 00' 520's to the 03's in various SX, EXC, MXC models.  We have experienced ZERO valve train malfuntions, or for that matter, any reliability issues among these bikes.

Now,....here is where all the people with issues will key in, and tell you all the problems they had with their RFS, but how many of them are/were related to maintaince neglect...(ie; valve adjustments, break-in procedures, maintaince intervals, ect.)

And I am sure there are people who properly maintained their RFS, and still experienced problems, but I feel this remaining ratio of incendents are about as common as any other internal combustion engine.

Take a look through some of the YZF and CRF forums..., no shortage of reliabilty issues there.
 
Joined
Jul 4, 2001
Messages
432
Likes
0
#6
Hey Shaw, Dont forget that your bike survived Paragon several times! That says it all.
 

Shaw520

Damn Yankees
Joined
May 14, 2000
Messages
1,082
Likes
5
#7
 Yes Trigger, a few good beatings at Paragon, to ad to a very long list of D34  H/S's and MX's.  
 

"rippinrol"

aka tippinroll
Joined
Jun 11, 2002
Messages
160
Likes
0
#9
Many beatings and tanks of gas has gone thru mine and she still rips a nut.
 

Shaw520

Damn Yankees
Joined
May 14, 2000
Messages
1,082
Likes
5
#10
Hmmm....... Looks like ripper's expecting a new baby,......... :aj:
 
Joined
Aug 13, 2000
Messages
826
Likes
5
#11
Right, well,

I will be probably be purchasing a friends 2001 520EXC. I know the bike well enough as I probably have as much time on it as the owner. It has never failed me on those long days either.

If there is a weak spot, I would like to correct it. I generally ride by myself and often times hundreds of miles from home in the middle of the Ocala National Forest. I really do not like pushing a dirt bike in the sand:)

Thanks for all the responses!

Chris
 

"rippinrol"

aka tippinroll
Joined
Jun 11, 2002
Messages
160
Likes
0
#12
Originally posted by Shaw520
Hmmm....... Looks like ripper's expecting a new baby,......... :aj:
:) I expect one soon, we thought long to come up with a name and came up with 450sx.. :yeehaw:

cujet, if you have any questions DRN will provide answers.
 
Last edited:

Tony Eeds

Welcome Wagon
N. Texas SP
Joined
Jun 9, 2002
Messages
9,544
Likes
0
#13
Originally posted by "rippinrol"
cujet, if you have any questions DRN will provide answers.
:thumb:

re KTM, I have had mine for almost two years without a problem. Of course, I couldn't ride for almost 6 months because my foot was broken. :whiner:
 

bsmith

Wise master of the mistic
Joined
Jun 28, 2001
Messages
1,782
Likes
0
#14
updated nut&wheel for the auto decomp and you should be set.
I would agree, I had the nut come off the bolt and the cam lobe drive it through the buttom of the reservoir and into the coolant system. It was about a $120 weld job, yet much more for the labor and some other things I had done.

My bike was purchases used in Nov of 01', the previous owner was a bike shop who had raced it. All in all still no regrets :thumb:
 

Zoomer

Lifetime Sponsor
Joined
Nov 17, 2000
Messages
835
Likes
0
#15
I really do not like pushing a dirt bike in the sand

Cujet,

The best thing I ever did was put the button on mine!
Its as much fun "pushing the button" as riding the bike :yeehaw: My old yzf never gave me any problems starting hot or cold. But I've seen to many KTM riders kicking there buts off after killing the engine usually in the wrong place.(hill side kickstarter up hill) Ive tried all sorts of ways of killing the engine, (letting it sit on its side) etc, starts in a couple seconds everytime! GREAT BIKE