Jump to content

Are the RFS motors typically "noisey"?

Recommended Posts

Yesterday I washed my 05 525 exc and, as I usually do I put some sta-bil in the tank and fired it up to build up a little heat and dry things out a bit and get some of the sta-bil into the carb. I pushed it back into the garage and let it idle on the kick stand while I hosed off the driveway. The engine noise is loud, very noticeable. I haven't really ever listened to it from that angle/distance, so Idk if it's something new or not. I know when I'm on the seat it seems alot of engine noise bounces off the alum skid plate. I had started it once w/o the skid plate and it's noticeably quieter.

A little background. When I got the bike back in Jan. it had 1140 miles on it and the electric start didn't work. The starter sprague clutch and the idler gear and such were all broken to bits. I did do the carb work and started it a few times while all those pieces were flying around in there. So, I took out all the broken pieces(so no e-start) and filled it with oil ,ran it a bit, drained it, cleaned the screens, filled it again, repeat. I did this about 5 or 6 times running it a bit more each time, even going on a ride and draining it each after each ride. I always drained the oil into a clean white container so I could see what the oil looked like. The last time I did it the oil was nice and clean after a 90 mile ride.  

So, I'm sure the screens/filtering systems work really well to keep debris out of critical areas. I'm new to KTM. But, this is always in the back of my mind when I'm out riding. It seems like the deeper I get into a steep, remote canyon the louder and more noises I hear. LOL. One of my buddies says that the European 4 strokes are typically noisy. What say you?

Share this post


Link to post
Share on other sites

My 2006 525EXC sounds like a bunch of marbles shaking in a tin can. I was worried at first as I too bought my bike used with about 2k miles. Now I just ignore it as I have asked many other riders and they said "that is just how they are"

Edited by Dwrizzol
Sp.
  • Like 3

Share this post


Link to post
Share on other sites

Yes, the RFS is a noisy engine.  That said, there are pattern problems that can make it noisier.  I have owned my '05 525 EXC for about 5-6 years and have had a couple problems that gave me noise.

One thing these bikes can have happen is that the main shaft nut can come loose due to differential heating and cooling.  This is because the nut is aluminum and is mounted on a steel crank.  When this happened to my bike it sounded like someone threw a box of rocks into my engine.  This was a cheap and easy repair using a steel nut from a newer bike.  The second issue I had was my crank spread causing a main bearing to fail.  This happened in BFE Nevada and had to nurse it back to Fallon.  This problem had been mostly worked out by '05 but it turns out I have an early '05 crank that was prone to this issue.  I have since had it welded and should be good to go for a good long time.

 

 

 

  • Like 2

Share this post


Link to post
Share on other sites

Replaced the entire valve train &  had DJH service the head- it's still a noisy engine. Keep your maintenance up. You can pull the screens and drain plug anytime to check engine "health". Put the bike on a work bench throttle side at an angle. The bottom screen will still leak oil, I keep an extra plug for that, not much from the rear drain or side screen.

  • Like 2

Share this post


Link to post
Share on other sites
8 hours ago, cobra46 said:

Yes, the RFS is a noisy engine.  That said, there are pattern problems that can make it noisier.  I have owned my '05 525 EXC for about 5-6 years and have had a couple problems that gave me noise.

One thing these bikes can have happen is that the main shaft nut can come loose due to differential heating and cooling.  This is because the nut is aluminum and is mounted on a steel crank.  When this happened to my bike it sounded like someone threw a box of rocks into my engine.  This was a cheap and easy repair using a steel nut from a newer bike.  The second issue I had was my crank spread causing a main bearing to fail.  This happened in BFE Nevada and had to nurse it back to Fallon.  This problem had been mostly worked out by '05 but it turns out I have an early '05 crank that was prone to this issue.  I have since had it welded and should be good to go for a good long time.

 

 

 

Thanks guys.

Should I check the VIN to see if I have the early 05? What's the cut-off date?

Share this post


Link to post
Share on other sites
1 minute ago, Bill DeWahl said:

Thanks guys.

Should I check the VIN to see if I have the early 05? What's the cut-off date?

 

I'm not sure what the cutoff date is.  My guess is they made a rev change to the crank in calendar year '04 but kept using their stock of cranks heading into the '05 model year build.  I was one of the unlucky people who got an '04 crank.

I think the cross section of the crank was drastically changed but don't quote me on that.

Both issues I had resulted in a bike that left no doubt that something was wrong inside.  The loose nut noise came on kind of slowly and got worse.  The main bearing went from 'I think my bike is getting louder' to 'oh crap, I hope I make it back to civilization' in about an hour.

 

Do you know anyone near you who also has an RFS?

Share this post


Link to post
Share on other sites

Where are you located?  Based on your SOJ avitar, you are somewhere in Norcal.  I'm in the southern part of SOJ.

Share this post


Link to post
Share on other sites

don't forget the clutch rattle they have. Also the 05 is a known issue for the starter clutch device in the right side case failing. The other year bikes do not have this issue.

Share this post


Link to post
Share on other sites

One of my coworkers has an 05 or 06 525. He did a lot of desert racing so his motor isnt original or stock. But I'll ask him anyway. 

So, it sounds like I need to check on the crank nut and clutch. I'll do that before I ride it anymore. The starter clutch and the other gears are gone already.

I'm about 50 miles north of sacto.

 

Share this post


Link to post
Share on other sites
1 hour ago, Bill DeWahl said:

One of my coworkers has an 05 or 06 525. He did a lot of desert racing so his motor isnt original or stock. But I'll ask him anyway. 

So, it sounds like I need to check on the crank nut and clutch. I'll do that before I ride it anymore. The starter clutch and the other gears are gone already.

I'm about 50 miles north of sacto.

 

Have him give your bike a listen.  If he's ridden an RFS for any length of time, whether modified or not, he will be able to tell you if it sounds normal.  Another idea is to make a short video and upload it to YouTube for all of us to listen to.

Share this post


Link to post
Share on other sites

My co-worker suggests checking the valves. Knowing a little bit of the history of  this bike I would bet a weeks pay that they've never been touched. It has 1350 miles on it right now. Getting the bike to him or vice versa might be tough. I'll ask him about it. 

I'll try the video thing. Never had much luck with it, but I'll give it a shot later.

You have a Cobra? 

Share this post


Link to post
Share on other sites

My screen name is three fold. The AC Cobra is my favorite car, 20 years ago I bought a new Cobra Mustang but sadly I sold it.  Also I was a Cobra AH64 mechanic in the Army.

I'm kind of itching to get another Cobra.  The new ones are awesome.

The valves tend to get tighter on these bikes so they wouldn't become more noisy over time.  As the valves get tight, the bike gets hard to start. Typically the intakes move a lot and the exhausts not so much.

 

 

 

  • Like 1

Share this post


Link to post
Share on other sites

the noisy clutch is normal...louder shen it is in neutral and lever out-pull lever in and it quiets down a little-normal. The clutch plates last a loonngg time on these.

Valves are easy to adjust using the 1/6th turn method. Buy new valve cover gaskets before you take it apart.

The only other thing I can think of is the cam chain does rattle some too. Make sure the cam chain tensioner is still working properly.

 

Share this post


Link to post
Share on other sites

Don't remember what year bike you had Mike.

The intakes were terrible soft, exhaust were fine, so most valve issues were "I" and we generally replaced all 4 with the Kibblewhites. Fairly reliable with once a year clearance checks for average riders.

Share this post


Link to post
Share on other sites
18 hours ago, cobra46 said:

My screen name is three fold. The AC Cobra is my favorite car, 20 years ago I bought a new Cobra Mustang but sadly I sold it.  Also I was a Cobra AH64 mechanic in the Army.

I'm kind of itching to get another Cobra.  The new ones are awesome.

The valves tend to get tighter on these bikes so they wouldn't become more noisy over time.  As the valves get tight, the bike gets hard to start. Typically the intakes move a lot and the exhausts not so much.

 

 

 

:thumbsup:

I got some vid, I'm gonna try to put it up on youtube. 

Share this post


Link to post
Share on other sites
46 minutes ago, UH1H said:

If you have a aluminum skid plate the noise is amplified.  

Ya. I'm aware of that. 10 years ago I bought a crf250x and after I had it a while, I made an aluminum skid plate for it. When I fired it up the 1st time with the skid plate on,  I totally freaked out! Until I realize what was going on. I sprayed 3 coats of rubberized under coating on the s.p and it helped some.

  • Like 1

Share this post


Link to post
Share on other sites
Posted (edited)

06 525 exc.  Rebuilt over a year ago.  Was noisy when I got it in a trade.  Exhaust valves were at .032" lash....wtf!  Reset using the 1/6th method.....quiet now.  When its hot, 180+ it makes typical bike noise.  If I have it on the aluminum stand, its much noisier.  On the kickstand, all I hear is a slight valve tap(barely audible), and the slight whirling sound.  Has a rekluse in it so clutch is quiet. 

My buddies have the polaris outlaws with the ktm 525 RFS motor.  One is noisy as all get out, the other is quiet as a mouse.  Both get raced hard (endurance races).  I think its hit or miss....

Edited by KeyKeeper
  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×