2012 KTM 500 EXC Refresh

Joined
Jul 11, 2021
Messages
853
I picked up a 2012 KTM 500exc last spring. I wanted something I could ride from my driveway to a large trail network that can be accessed about 6 miles from my house.
It had 25 hours on it and 1100km on the odometer. I put 60 hours/1000 km on it over the summer, mostly tight woods single track.

A few pics in its natural habitat.
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I'm not easy on this machine at all, it gets dirt naps pretty much every ride and has slid down some hills, bounced off of trees, etc. I do however try to maintain it really well. Mostly because I often ride alone 30-40km into the woods with no access other than dirt bikes, sometimes not sure I will get myself out with a running bike. Also I enjoy wrenching on bikes.

My winter project is to tear this bike down to the frame and go through all the components, addressing any issues that come up. I also have some mods/upgrades planned as well. The biggest concern I have is the wiring, KTM dirt bikes are known for bad wiring, I've already had to fix a couple broken wires. Most of the connectors are no sealed and are packed full of dirt and starting to rot and corrode. The wiring harness will get a complete inspection/repairs and all connectors replaced with sealed connectors.

Its a big list but here is what I'm thinking:
  • Rad hoses
  • Inspect clutch
  • Larger idle screw
  • Clean injector
  • Check all wiring
  • Replace connectors with Waterproof connectors (Sumitomo ?)
  • Valve clearance
  • inspect brakes
  • Rear brake switch connector redo
  • Low fuel light check
  • High beam light check
  • New battery
  • Fork rebuild
  • New Fuel pump
  • Wheel bearings
  • Ground strap
  • Kill/start switch
  • Inspect kick stand innards
  • Rear sub frame corrosion.
  • Fix radiator and bend tab for plastic mounting
  • Install rad braces
  • Replace counter shaft seal
  • Fix wiring behind headlight mask
  • frame guards
  • New Battery in gauge cluster
  • Balance wheels and check run out
  • Rad cap
  • Battery fitment
  • Spring washer on ground cables
  • Inspect water pump
  • Throttle cable boot
  • Elastic mount rad shrouds
  • New brake pedal w/ tether
  • Repack muffler
  • Install threaded bar inserts
  • Weld wing nuts onto throttle body bolts for trail side removal or replace with 6 or 8mm head bolt and carry ratchet wrench?
  • Check condition of throttle body boot
  • Fix tear in seat
  • New chain sliders
  • Make Rear running light stays on when headlight switch off
  • Check for vacuum leaks
  • Check TPS voltage
  • Make short bolts for bottom or front fender
  • 3m headlight lens
  • Longer shift lever
  • Rebuild kick stand
  • Clutch Slave gasket
  • Check steering head bearings
  • Machine Clake 2 clamp for better clearance
  • Install heavy belleville clutch spring
I might have some things down twice, the list has been ongoing over the last 6 months as I thought of things.
I've already started the process. Pics won't be the best for the first few posts as I wasn't planning to post any of this but should get better as we go.
 
Next step: Remove the "T-Pipe" coolant pipe from the frame. They make a special tool for this but since I'm not reusing it I didn't purchase it. I chose the brute force approach.

Here is the pipe, it sticks out each side of the frame to connect the radiators and has a small piece of pipe coming out the bottom. It has a big restriction and these bikes need all the cooling help they can get when used in tight trails.
image006.jpg

This didn't come out easy, I ended up putting a bar through the frame section and a pipe wrench on the bottom with a 14mm allen key jammed in to stop it from squishing the pipe. Had to heat it but after a bunch of swearing it gave up.
image007.jpg
 
I picked up a 2012 KTM 500exc last spring. I wanted something I could ride from my driveway to a large trail network that can be accessed about 6 miles from my house.
It had 25 hours on it and 1100km on the odometer. I put 60 hours/1000 km on it over the summer, mostly tight woods single track.

A few pics in its natural habitat.
View attachment 127686
View attachment 127683
View attachment 127684
View attachment 127685



I'm not easy on this machine at all, it gets dirt naps pretty much every ride and has slid down some hills, bounced off of trees, etc. I do however try to maintain it really well. Mostly because I often ride alone 30-40km into the woods with no access other than dirt bikes, sometimes not sure I will get myself out with a running bike. Also I enjoy wrenching on bikes.

My winter project is to tear this bike down to the frame and go through all the components, addressing any issues that come up. I also have some mods/upgrades planned as well. The biggest concern I have is the wiring, KTM dirt bikes are known for bad wiring, I've already had to fix a couple broken wires. Most of the connectors are no sealed and are packed full of dirt and starting to rot and corrode. The wiring harness will get a complete inspection/repairs and all connectors replaced with sealed connectors.

Its a big list but here is what I'm thinking:
  • Rad hoses
  • Inspect clutch
  • Larger idle screw
  • Clean injector
  • Check all wiring
  • Replace connectors with Waterproof connectors (Sumitomo ?)
  • Valve clearance
  • inspect brakes
  • Rear brake switch connector redo
  • Low fuel light check
  • High beam light check
  • New battery
  • Fork rebuild
  • New Fuel pump
  • Wheel bearings
  • Ground strap
  • Kill/start switch
  • Inspect kick stand innards
  • Rear sub frame corrosion.
  • Fix radiator and bend tab for plastic mounting
  • Install rad braces
  • Replace counter shaft seal
  • Fix wiring behind headlight mask
  • frame guards
  • New Battery in gauge cluster
  • Balance wheels and check run out
  • Rad cap
  • Battery fitment
  • Spring washer on ground cables
  • Inspect water pump
  • Throttle cable boot
  • Elastic mount rad shrouds
  • New brake pedal w/ tether
  • Repack muffler
  • Install threaded bar inserts
  • Weld wing nuts onto throttle body bolts for trail side removal or replace with 6 or 8mm head bolt and carry ratchet wrench?
  • Check condition of throttle body boot
  • Fix tear in seat
  • New chain sliders
  • Make Rear running light stays on when headlight switch off
  • Check for vacuum leaks
  • Check TPS voltage
  • Make short bolts for bottom or front fender
  • 3m headlight lens
  • Longer shift lever
  • Rebuild kick stand
  • Clutch Slave gasket
  • Check steering head bearings
  • Machine Clake 2 clamp for better clearance
  • Install heavy belleville clutch spring
I might have some things down twice, the list has been ongoing over the last 6 months as I thought of things.
I've already started the process. Pics won't be the best for the first few posts as I wasn't planning to post any of this but should get better as we go.
KTM makes gorgeous machines
 
I used my thread chaser kit to clean up all the threads on the frame, some were really packed tight with locktite.

Next I cleaned up the frame, removed the factory info and warning stickers that were all illegible and touched up some of the worn spots with semi-gloss black. I considered having the frame powder coated but decided against it. Maybe that will be next winters project.

Bad pic but I'm really happy with how it turned out.
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Once the paint was hard a day later I gave it a two applications of turtle wax spray ceramic coating, maybe it will help it clean up better, took no time at all.
 
Now that the frame is ready lets get some components ready to bolt onto it.
Swingarm:
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When I pulled the swingarm pivot bolt there was some rust so I knew the bearings would be shot.
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I used a bridge style blind bearing puller, with some heat applied they came right out:
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One side wasn't bad but the other side would have became a problem.
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I also pulled the heim joint from where the shock attaches to the swingarm, it appeared fine but it was cheap, in stock and now I don't have to worry about getting water/cleaner inside it when cleaning the swingarm.

Which is my next step, cleaning the swingarm, I have some aluminum wheel cleaner I plan to try, it's stained pretty good so hopefully it works well.
 
It looks expensive. I just enjoyed riding back in my youth. Air cooled 2-strokes were cheap and fun. No water pumps, hoses, or fuel injectors to deal with. Just the occasional splash of Golden Spectro in the fuel mix and off we'd go for another trail exploration in the fabulous hills of West Virginia.

KDX175.jpg
 
It looks expensive. I just enjoyed riding back in my youth. Air cooled 2-strokes were cheap and fun. No water pumps, hoses, or fuel injectors to deal with. Just the occasional splash of Golden Spectro in the fuel mix and off we'd go for another trail exploration in the fabulous hills of West Virginia.

View attachment 127722
I hear ya! I grew up riding the same kind of bikes and I held off getting a FI trail bike for as long as I could but I have to say I'm glad I did, the performance of these machines is on another level. I do miss a machine having a wiring harness that could fit into a pocket thou!
 
It looks expensive. I just enjoyed riding back in my youth. Air cooled 2-strokes were cheap and fun. No water pumps, hoses, or fuel injectors to deal with. Just the occasional splash of Golden Spectro in the fuel mix and off we'd go for another trail exploration in the fabulous hills of West Virginia.
It's funny, but I was thinking the exact same thing. I do really like the KTM big bore EXC's, but they are complex. My fav bike was a well modified IT490, street legal of course.... I rode one of these all over the place while in college. It was good at it all, from the motocross track to I-95. Top speed was well over 100 with highway gearing. So it was quite relaxed at the 65mph limit

nYWTCbq.jpg
 
Back to the OP, I do think you should have powder coated the KTM's frame orange! Nice job on the wintertime overhaul. Looks like you will have a great bike going forward.

2018-Washougal-motocross-4783.jpg
 
It's funny, but I was thinking the exact same thing. I do really like the KTM big bore EXC's, but they are complex. My fav bike was a well modified IT490, street legal of course.... I rode one of these all over the place while in college. It was good at it all, from the motocross track to I-95. Top speed was well over 100 with highway gearing. So it was quite relaxed at the 65mph limit

nYWTCbq.jpg
Where is this? I could spend some time looking(drooling) in that place! Lots of nice machines!
 
Back to the OP, I do think you should have powder coated the KTM's frame orange! Nice job on the wintertime overhaul. Looks like you will have a great bike going forward.

2018-Washougal-motocross-4783.jpg
I strongly considered it, probably will next winter.
I'm split on the orange (the 15-16 bikes from this gen are orange), I think the black will look good when I'm done. I have some plans that will refresh the look of the bike coming also. You will have to wait and see.
 
I hear ya! I grew up riding the same kind of bikes and I held off getting a FI trail bike for as long as I could but I have to say I'm glad I did, the performance of these machines is on another level. I do miss a machine having a wiring harness that could fit into a pocket thou!
Why stop, they are best bike in the world to ride, Im 60 and these are still my favorite bikes to ride, cause they offer much entertainment.
I ride a KTM 500 also. My sport bike is kinda boring in comparison.
 
Oh man, that Kaplan youtube channel is great. The first thing that popped up was a 1977 RM-250. I was racing one of those before Kawasaki and "Team Green" decided to give me a couple of bikes to ride. I definitely need to take a trip up there and check that place out.
 
Got some more cleaning done. I would rather do mechanical work but I'm OCD about cleanliness and it is kind of satisfying.

Started with the swingarm:
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First I tried simple green HD (the purple stuff) with a stiff bristle brush. Didn't do much except take off some of the loose dirt:
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Next I tried the simple green with a scotch brite. Better but not great and took a lot of effort:
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Then I tried some Mother's Aluminum Wheel Cleaner combined with the scotch brite and got some good results:
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Looking good!

How's that lower shock bearing?
It was fine actually but I removed it since it was fairly inexpensive and I didn't want to worry about getting water/cleaner in it during clean up. They use a heim joint rather than roller bearing. I have a new one ready to go but waiting on swingarm bears before I can reinstall the swingarm.
 
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