520 Shifting Problem - Need Help

I have had my 2003 520 EXC since new.  Been well taken care of, has relatively low mileage and has many upgrades.

 

Always been a good and faithful bike until late last year riding at Kooteney Lake north of Kaslo I was heading to a trail head (riding on the gravel beside a road) when I got on the gas and the tire was spinning when I hit the pavement and - bang - the chain snapped.

Didn't have all my fix-it stuff with me so I put it back in the trailer and rode the Yamaha 550 Grizzly for the weekend instead.

 

Fast forward to the next ride (last ride of last year before sledding season) - was doing a ride behind the Fernie ski resort on October 26th and all was good for the first 10 miles or so when I came to a deep creek crossing and the bike hit neutral half way across and I ended up falling in the freaking frigid water. 

 

Eager to get back to the truck and dry off we set off on the fastest way back. The bike was ok but would hit neutral randomly.  A bit further on the trail and it stopped shifting properly and so I rode the rest of the way back in 3rd or 4th gear.  Thank God for good torque.

 

So this spring I did an oil change and started the beast up and went for a test ride. Basically it shifts up a couple of gears and then hit neutral or not shift gears at all. Shift lever is on tight and it clicks like it is changing gears but doesn't shift consistently at all.

 

I'm hoping this is a problem with shift stuff that is accessible from the right side cover and not anything more. Anyone had similar issues or can offer advice...?

 

Much appreciated.

 

 

Same happened to a friend with an '01 520. It took ten years. The factory improperly shimmed the gearbox. Check output shaft slack (in/out). There's a service bulletin out on it - years ago. The engine needed to be torn down. Older mechanics on ktmtalk might be a better reference.

I was going to bet that you picked up a rock in the chain which caused it to break while simultaneously putting a whopper amount if stress on the countershaft breaking something inside. That's my guess anyway.

 

This video (not mine) shows a problem with the shifter but it doesn't really explain anything and I don't know how it is supposed to work.

If someone could explain the operation shown there then I could compare it mine. 

 

Thanks.

I was going to bet that you picked up a rock in the chain which caused it to break while simultaneously putting a whopper amount if stress on the countershaft breaking something inside. That's my guess anyway.

 

The chain was the original factory one from 2003 and was stretched and needed replacing.  It was also slack at the time as were just doing a 5 minute ride and going to take the bikes back to prep them for a long ride the next day. Could have been a rock but more likely just the sudden transition from spinning to hooking up on the pavement. 

I know KTM was telling owners not to dual-sport the EXC's back then as they didn't think the transmission could handle the torque.

This is one guys experience and cure. I don't know if it is the same problem but...

 

Well here is an update:

 

Took the right side engine cover off and clutch out. Everything looked ok - as in no bent or broken parts - however trying to shift gears while spinning the gears ended up doing more or less the same as when riding it.  

One thing I did notice however was the bolt that holds the Shift Locating Drum (round aluminum thing) was slightly loose.  The manual says it should be have Loctite on it so it certainly shouldn't have been loose.

Anyhow I put some Loctite on the bolt and tightened it up and left it for a while. When I returned later to check it everything seemed better (shifting by hand) so I put it back together, put some oil and took it for a ride.  So far, so good.  I went up and down through all 6 gears under light load using the clutch on each shift and all is well... 

 

I will take it for a more rigorous ride later and report back...!

Thanks for the update. All too often we don't hear what the problems were with a quick follow up from OP's. Glad it wasn't anything major. :thumbsup:

Well here is an update:

Took the right side engine cover off and clutch out. Everything looked ok - as in no bent or broken parts - however trying to shift gears while spinning the gears ended up doing more or less the same as when riding it.

One thing I did notice however was the bolt that holds the Shift Locating Drum (round aluminum thing) was slightly loose. The manual says it should be have Loctite on it so it certainly shouldn't have been loose.

Anyhow I put some Loctite on the bolt and tightened it up and left it for a while. When I returned later to check it everything seemed better (shifting by hand) so I put it back together, put some oil and took it for a ride. So far, so good. I went up and down through all 6 gears under light load using the clutch on each shift and all is well...

I will take it for a more rigorous ride later and report back...!

Same thing happened on my kx250f a while back, that shift drum can bolt gets loose and it will just not work right ha

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