Repowering a KTM 640 Adventure

Discussion in 'Some Assembly Required' started by Z50R, Oct 19, 2017.

  1. Z50R

    Z50R Not lost yet

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    Radiator fan. There wasn't much space on the left radiator and even less on the right so I decided to balast down the left side of the bike a bit more. The fan will just bearly fit under the return hose and in front of the head.


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    You can't see but there is a small fold/lip on the inboard seam of the radiator similar to the one just above my thumb in the photo above. I am using that lip and the mounting screw that was used to secure the DRZ plastics to hold the fan in place.

    Start by cutting a sheet of 16 gage and folding two 90s in it to make it stiffer.

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    I forgot to take pictures for a bunch of steps. I cut a notch in the two upturned edges and folded a 90 in the main sheet. I drilled, punched, and notched an opening for the fan and its mounting screws.

    To keep the mounting screws from digging into the radiator, I recessed the mounting holes. I did this by using a socket as a die, and a chisel as a punch. I blunted the metal chisel cutting edge and flipped it around. I pressed it into the piece by hitting what would normally be the cutting edge and using what was the handle as a large tool steel round punch.

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  2. Z50R

    Z50R Not lost yet

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    I filed down the screw mounts to keep the fan close to the radiator despite the recessed mounting holes.

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    Some trim work to the edges, a screw hole, and a slot finish out the part. Sand and wire brush liberally.

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    And mount it on the bike.

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  3. Z50R

    Z50R Not lost yet

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    I started screwing around with items on my list of electrical parts to mount. I picked the turn signal relay and walked over to the bike. 3 and 2/3 seconds of stairing at the jumbled mess where the headlight goes and the ever expanding puddle of fork oil and I put the relay down. Time to start working on the difficult parts.

    I tore the front end off the bike. Here's the lower triple clamp with fender and brake line guides. My plan is to use the four fender mount screw holes to attach the fender and brake line guides as is currently the case but to also catch the bottom of the headlight ring.

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    I got lucky and scored a rather large piece of 1/4" plate steel for free. I don't normally work with steel this thick but it works well here so long as the diet I put it on is strict. I cut a chunk off the plate and squared up 3 edges. I drilled for the fender mount holes and hit my mark.

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    Lots more drilling. I drilled and tapped holes for the brake line guides. I drilled pilot holes to mark where the headlight ties in and to allow the tubes to vent while I weld. I drilled a giant weight savings hole and I drilled a hole wherever there would be an inside radius.

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    Some destruction was administered via angle grinder.

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  4. Z50R

    Z50R Not lost yet

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    That diet I was talking about was given by the power sander. I gave most parts a 2 mm wall thickness. I am happy with the weight reduction.

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    Another test fit, success!

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    A recess was cut in the back of the central ring to clear the stem.

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    And a test install has steel tabs exactly where I need them.

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  5. Z50R

    Z50R Not lost yet

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    This post doesn't convey how much time was spent screwing around trying to determine forward/back position and angle of the headlight relative to the stem but I worked out a location and angle on the fender and cut two lengths of tube with a 120 degree bend.

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    And welded

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    Test fit is still good.

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  6. Z50R

    Z50R Not lost yet

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    The welded joint attaching the headlight ring to the fender mount is tricky. The part has to be centered, leveled, twisted side to side appropriately, and tipped up or down appropriately. All of that has to be done without a jig because I can't think of an easy way to make one without wasting a day of fabrication.

    I leveled the fender bracket side to side. Next I taped a level to a rod that ran between the two light mounts.

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    This gives me one less variable to guess at while tacking. The first attempt had the ring too high. Break it, sand it, and try again. Try two landed the ring where I wanted it.

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    That is as far as I got. The front end of the bike is a jumbled mess right now. I am working out how to tie the top in while leaving space for cables, brake lines, the key, speedometer, the GPS, and not interfearing with fork or headlight articulation.
  7. clintnz

    clintnz Trans-Global Chook Chaser

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    Love your work on that lower headlight mount bracket! I've made stuff a bit like that out of alu but have never done anything that complex in steel. Getting everything to fit in around the headlight sure is a challenge if you want to keep it tidy & compact.

    Cheers
    Clint
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  8. Z50R

    Z50R Not lost yet

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    Progress slowed again as more important things in life took priority. When I got time to work, I was stumpped by what to do next and spent a decent amount of time just looking at the mess and moving the speedometer, GPS, and key switch around looking for places they'd fit. In an attempt to make some progress I tried making a mounting plate for the speedometer. The plate was a tight fit to the mounting points, offered no protection to the electronics from rain nor impacts, and didn't open up any good ways to mount the speedometer. I scrapped the plate and decided that even if I don't know where the speedometer is going to go, at the very least, it needs an enclosure.

    I thought about what KTM had used on the 640 Adventure. The plastic dash is light weight but I decided against a plastic dash because it doesn't address the problem of attaching the speedometer to the bike, it only offers to move the bolt interface between plastic and metal to some other location. I looked at other KTM bikes to see other ways of addressing the issue but decided that buying anything wouldn't make my goal of fitting everything in a compact package any easier. I decided that a metal enclosure would allow me to weld the speedometer wherever I wanted and worst case would be scrapped again. Better to do something than stand there scratching myself

    I decided to leave the back off the enclosure. On the 640, the bike would collect rain water in the enclosure and spit it out at the rider as speed and vibration picked up. I am looking to give a better path out for water that finds its way in. I also decided some kind of sun shade would help with reading the speedometer since the fairing has been banished. I decided that this part should be stainless steel as well, the speedometer is both high up and far forward. It will see some impact damage, stainless where the paint will come off is a bonus.

    Ok, enough blather, on with the pictures:

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    This is a piece of stainless from a house I rented. It was in the pile of stuff the previous tennant had left behind. I have been carting it around for most of a decade, finally it gets put to use.

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    I left the top bend in the previous picture and cut the bottom off. Hacked and squared up the ends, and punched out some holes.

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    Notched the bottom and opened up the holes. Next are a pair of 90 degree bends.

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    And since the sun shade would act as a knife in a wreck, I bent it away from the direction that would cut into the rider.
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  9. Z50R

    Z50R Not lost yet

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    In an attempt not to repeat the previous mounting plate fitment issue, I imprinted the mounting studs on paper, laid the paper over the sheet metal, and center punched through the paper. The center stud is centered side to side on the computer but all bets are off on KTM's placement of the other two, they are not symetrical.

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    The fit this time is excellent!

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    I trimmed the bottom of the folds back to reduce weight and welded in washers to add thickness where necessary

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    The speedometer installed in its new home. I ended up trimming the bottom a bit closer to the washers after this picture to shave a bit more off the weight.
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  10. Z50R

    Z50R Not lost yet

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    With the enclosure done I was able to move it around the bike with a better eye on how I might attach it to the bike. I decided that the headlight tilt mechanism could be trimmed a bit to open up space front and center. Some bent 1/2" tubing would attach the part and continue the tube structure look I seem to be gravitating to.

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    45 degree bends with 1/4 of the tube removed for 1 inch. The ends were peened over and the top welded shut.

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  11. Z50R

    Z50R Not lost yet

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    So the bike is coming along nicely and I am thrilled with most aspects. The rear rack looks cool but isn't strong enough so it needs more love. The only thing I have done so far that I am extremely dis-satisfied with is the headlight tilt mechanism.

    Because the axis of the bolt used to aim the headlight does not point through the pivot axis, a washer placed around it will not trace an arc as the light is tilted. Instead, it translates through its travel. I tried fudging this problem with rubber washers but the net result is heavy, clunky, and ugly. additionally, because I need the vertical slot to be stiff, it had to be double walled (tubing) but both surfaces of the tubing needed to trace a precise arc that couldn't be defined until the part was welded in place at which point it is too late to define them! Again I fudged the problem. The vertical slot had an additional problem in that it is a collection point for mud that would be difficult to clean. Finally, the inside of the slot would be extremely difficult to protect from rust. Too many fudges multiplied by bad workmanship made a sour situation worse.

    I decided that that the headlight tilt mechanism was too prominant to have a series of bad choices ruin the lines of the bike and cut the whole mess off.

    I spent about 6 hours designing and building a really slick tilting mechanism with telescoping screws, roller bearings and a clicker index system before realizing that while cool, it was unnecessarily complicated and heavy. That got scrapped too.

    The third try was much closer to what I wanted but I sized it wrong and had to scrap a third time.

    This is the fourth try. I went from hating my tilt mechanism to really liking it so while it took forever to build, its simplicity and weight savings were well worth the exercise.

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    I went searching through my piles of junk I have picked from scrap metal bins and my eye caught the quick release skewer from a bicycle wheel. There's a handy way to hold something in place that can be quickly adjusted! This skewer conveniently comes apart so I cleaned it up and made it a lot shorter.

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    I took the tilt adjustment bolt and ground the shank flat on two sides, drilled a hole, and shortened the threads. The mess of washers and spacers is replaced by a single jamb nut.

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    1/8" plate is cut to size and notched for tubes

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    A shit ton of careful measuring and I still got this wrong the first time. These are the plates after the second try (hence 4th attempt rather than 3rd).
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  12. Z50R

    Z50R Not lost yet

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    IMG_0957.JPG

    The slots were marked by tacking a plate in place, marking, and removing the plate again for the cut. By breaking the tack rather than grinding it off, the absolute location of the plate can be found again by piecing the broken halves of the tack back together. The slots were cut by chain drilling along the arc and cleaned up with a dremmel and a file. More holes because holes weigh less than metal. And they look cool.

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    I leveled the headlight ring and screwed it to my work bench so that I could get this whole mess right this time.

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    With everything welded in place and on the bike.

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    We have a speedometer!
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  13. 2002maniac

    2002maniac Adventurer

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    That looks fantastic! Great job integrating the dash and headlight ring assembly.
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  14. Z50R

    Z50R Not lost yet

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    So I turned what should have been something difficult into something surprisingly simple then made it more complicated than it needed to be.

    The GPS needed to be mounted either on the handlebars or next to the speedometer. I chose next to the speedometer because there is an awful lot going on with the bars already.

    I picked the left side so the non throttle hand can screw with it while riding easier. My plan was to weld a tab to mount the GPS to but that would require some additional bracing to prevent a fatigue failure and a cage to protect the unit. Looking at the situation, I realized a well placed RAM ball could avoid the mounting nightmare and would allow the GPS to be swapped out for the roll chart should I need it again. Additionally, using a RAM mount allows movement in a wreck that has as good a chance of saving the electronics as a cage would while being significantly lighter.

    I took a RAM ball with a 1/4 x 20 threaded stud and removed the stud. I drilled it to 17/64ths and tapped it to m8 x 1.25. I have to deal with mixed fasteners at work and on previous bikes but do not want any standard tools to be needed for this one. The hex under the ball needs a standard wrench but an 11mm will fit and either way, the ball can be held by a mount should it need to be loosened later.

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    Simple and out of the way when no navigational aids are in use.

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    With the GPS in position.

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    And with the roll-chart holder.
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  15. Z50R

    Z50R Not lost yet

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    This past weekend I finished the welding on the headlight ring. I added mounts made of angle iron to where the ignition switch was and where the upper left brake line guide tied in.

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    Since the key switch was removed from it's home to make space for the light and its mount, a new home had to be made for it. I did this by welding on two studs and cutting some custom nuts to fit the counterbored holes.

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  16. Z50R

    Z50R Not lost yet

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    A home was also made for the turn signal relay. It is tucked in beside the key switch such that it can only be removed (read: fall out) if the key switch is removed first.

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    A tab was made for the upper left brake line guide to mount.

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    And the guides were trimmed and installed (one is on back order)

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  17. Z50R

    Z50R Not lost yet

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    And an overview of the mess before paint:

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  18. Z50R

    Z50R Not lost yet

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    Today I finished the rear rack. I started by extending the rack a few inches. This is to give the giant loop a place to grab onto far enough back to allow the bag to sit over the rack where I want it.

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    And I finished by tying the bottom of the loops to the grab handles.

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  19. Z50R

    Z50R Not lost yet

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    Despite selecting the Leonelli hand controls a while ago, I was unable to cross them off my list until today. The wiring inside had to be cleaned up by combining two kill switch wires into one and eliminating an un-necessary headlight switch wire by unsoldering it at the board. After I finished my wiring work, I assembled the switch set and bench tested with no issues. After installing the switch kit on the bars, the turn signal switch failed. I rebuilt the switch again and same deal it works on the bench but fails after install. Turns out, tightening the switch kit on the bar causes the copper slide to compress. This puts a bend in it and poor to no contact is the result.

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    I mulled over my options:

    1. Buy a new Leonelli switch kit and take my chances that this is a design flaw.

    2. Buy a different aftermarket switch kit and roll the dice on a different short coming.

    3. Use the KTM switch kit and forgo the ability to kick start with all lights dark.

    4. Pay out the ass for a different OEM switch kit that does everything I want.

    5. Try to fix this one perminantly.


    The cheapest option is 5 so that is where I started. About $2.50 for a switch.

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    This switch will handle 5 amps and is spring loaded to center off and momentary on in either direction.

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    Fab up a mini bracket



    And we have a working switch better than OEM. Reassemble and test on the bike makes for success and another item crossed off the list.
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  20. The_Eccentric

    The_Eccentric Gearhead.

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    This thread has been a very interesting read. Problem solving at its best.:beer
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