2016-09-09 KTM 690 Rebuild


After almost 50k miles of abuse my 690 was in need of some love. I started small with just replacing some wheel bearings. Then I was having some issues with it stalling at idle. That one was hard to diagnose and ended up being a pinched fuel line in the gas tank (sorry no pictures). So I replaced the fuel line, feel filter and fuel pump while I was in there. Then I noticed a higher than usual oil burn. Pulled the cylinder and saw some significant damaged and thought it was time to learn about how motorcycles work and get into the engine to make sure everything was good. In the end I just took my time going step by step through the manual. Trying to come up with clever solutions when I didn’t have one of the many special tools. At one point I took the engine down to the local KTM dealer (Moto Cafe in Sunnyvale) to see if they’d be willing to help me pop off my fly wheel and primary gear. John in service was sympathetic to my cause and very knowledgable and helped me out in a big way when he didn’t have to. So shout out to him! In the end, I got a new cylinder and piston from Lyndon Poskitt and the parts bike from my buddy Cody. A few other new parts like time chain guide rail, valve stem oil seals, gaskets and odds and ends. Whole thing cost under $1,000 including all the tools I needed to buy and it was a great learning experience.

Update: Bikes been running great for the first 100 miles. Oil looks new. Temps are good.

(Hover over the pictures below for more details.)


  • Blown wheel bearing.

  • Lazy, wanted to ride, swap for super moto wheels.

  • Fresh bearings.

  • Cylinder damage.

  • Piston damage. Something got into the cylinder.

  • Setting up new workspace.

  • The swingarm pivot bolt was fused to the sleave of the swingarm bearings preventing it from releasing. It took me 2 hrs to figure that out get the motor out of the bike.

  • Workshop!

  • Looking like new inside.

  • John from The Motor Cafe in Sunnyvale!

  • Had to make room to work. Ducati had to go out in the yard. Drought == no grass.

  • My organization scheme.

  • Trying to figure out how a sequential gearbox works.

  • A folding bike.

  • And this is why the pivot bolt fused to the bearing. Chain was rubbing in patagonia and had no way to fix it.

  • Damn that cleaned up nice!

  • 50k miles of carbon.

  • Almost there.

  • All back together and looking spiffy.

  • Getting a motor in by yourself is tricky.

  • Found a parts bike to replace the swingarm.

  • Brand new shock came with the parts bike. Might as well. I have never touched my stock shock in 50k miles.

  • All done!



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  1. is that 50k miles or km? mine has 60.000km and is sitting in a ktm service for valve adjustment :)

    1. 50k miles. It was already on it’s 3rd camshaft and 4th set of rocker arms With a valve adjustment for each new set. What year is yours? They’ve continually made improvements to help this problem and have since redesigned the head.

    2. Curious about the rockers - did they fail, or were they replaced as preventative maintenance?

    3. A bit of both. But mostly got good at hearing when they were just starting to go and replace. The two times I didn’t notice in time led to needing to replace the cam shaft as well.

  2. mine is a 2009 bought and driven mostly here in slovenia, 2nd owner and everything is still original :)
    burns maybe from max to min oil in 4000km (service interval), so practically don't need to refill in between.
    I'm hoping for good news, but it's taking sooo long before the holidays for my mechanic to take it apart...
    If everythings fine i will go to 80.000km (50k miles) before the next "look inside"
    Since now i had the fuel pump + injector failure at about 42k km.
    It did stall afew times when cold since this summer.

  3. Interesting my Duke 690 had just ticked over 26000 miles and this week I thought the engine was sounding worse The rocker Arms are fine as is the tensioner as I checked these this morning. Going to run it a little longer but it sounds like noise from the bottom end.

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