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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    Switching gears back to steel, with the air box done but missing the mounting point for the coolant overflow tank, the sub frame had to come appart again for the addition of another tab.

    IMG_0706.JPG

    That is all the farther she got this weekend. I am trying to contain my excitement at this point. Most of the difficult work is done. At this point, the project could be completed with bolt on accessiries and a custom wire harness. I am trying to think of the most logical next step. I am leaning towards the headlight. I need a speedometer still but I think it will end up being mounted to the headlight housing. Either way, I can't do the wiring until I have all my electronics in place.

    I want the look of one of these:

    IMG_0672.PNG

    But also want it DOT approved/street legal. I am looking for a cheap/junked frame to the trailtech light but I may be forced to fabricate my own.
    #81
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  2. clintnz

    clintnz Trans-Global Chook Chaser

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    Interesting project!

    I built a mount for a std H4 7" round headlamp unit. Works well.

    [​IMG]

    I found a polycarbonate semi-sealed unit which is light & strong. Plenty of LED options out there now too.

    [​IMG]

    If you're planning on hauling much luggage add some more bracing to that subframe:

    [​IMG]

    The ribs underneath taper down all the way to the back both sides too.

    Cheers
    Clint
    #82
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  3. Z50R

    Z50R Not lost yet

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    Thanks for the ideas Clint.

    I am not too worried about the subframe. I have carried myself and all my gear for 4 years over some extremely rough trails without so much as a crack in the old subframe. Even still, I added a gusset or two. Worst case, it is steel, I find someone and have 'em weld it back together.

    I am curious about the construction of the mounting ring for your headlight. It appears you sammiched layers of 1/4" aluminum plate?

    I was looking at one of these as far as a lamp:

    IMG_0708.JPG

    http://www.kchilites.com/gravity-led-pro-7-headlight-single-dot-compliant.html

    It checks the following boxes:
    Low current draw (25 watts on high beam)
    DOT approved
    Polycarbonate lense (shatterproof)
    Waterproof to include full submersion
    No moving parts (fans or floppy heat sinks etc)
    No external parts like balasts or voltage regulators
    Doesn't look ridiculous

    They sure are pricy at $315 a piece but it looks like it does the job better than anything else I can find.
    #83
  4. clintnz

    clintnz Trans-Global Chook Chaser

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    Yup. Cut out the rings with a jigsaw then finished them on the lathe, without a lathe you'd probably need to laminate a few different layers to get the right thickness recess for the lamp flange, then take some time with file & sandpaper to get them pretty. The mounting tabs were chopped out of a piece of thick angle then turned down to match:

    [​IMG]

    I actually offset mine sideways a little so the back of it clears the key switch & can sit further back, this makes it less likely to auger into the ground during a tipover.

    I've thought about swapping to LED but I don't really do enough night riding to justify the expense. Plus the ones I've seen in person were also really heavy in comparison to what I have.

    Cheers
    Clint
    #84
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  5. Z50R

    Z50R Not lost yet

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    A coupla days ago I had a few free minutes and worked the plastics around the muffler. The following pic is hard to see but the middle black plastic on the rear fender was trimmed away from the muffler.

    IMG_0729.JPG

    The orange side plastic on what was the leeward side and now has the muffler was not designed with muffler like clearance. With the screws tightened, the plastic was acting as a spring held taunt against what will become hot metal.

    IMG_0730.JPG

    I gently heated the plastic with a Mapp gas torch and wedged a chunk of junk in between to re shape the plastic.

    IMG_0731.JPG

    IMG_0732.JPG

    Maybe a different day I will add a rubber bumper to the muffler mount to keep the plastic from getting jammed against the muffler in a tip-over.
    #85
  6. Z50R

    Z50R Not lost yet

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    So the war chest was running low and I really don't want to skimp on a headlight. In addition, I was getting really tired of tripping all over moto parts so I took a breather in the project and sorted out all the parts into three piles: things I know I need to bolt onto this bike, things I may need to modify and install, and things I know I don't need. A fire sale in the fleamarket and the war chest has some loot again. For the past three days I have been scrambling to pack and ship things. The sale thread finally calmed down today and I had some moto time.

    I started aimlessly toying with the air filter, then the rear rack, then the fuel pump but at no time did I accomplish anything useful. This is the really dangerous time in a project for me. The challanging part is largely done so my mind wanders and about now, projects peater out and get abandoned. This is fine if it is a bullshit project like most of mine are, but not so much when it is my motorcycle. I decided to make a list of what had to get done so I could have a clear goal when I get time to tinker.

    IMG_0735.JPG

    It is in pencil for a reason and there is still lots of white space on that paper to add stuff to the list. Again I tried to work on something but I had to walk away because I still was not in the correct mindset. Dinner and a beer and I got my head in the game. I picked the CDI mount.

    The CDI box conveniently fits in the location allocated on the airbox for the KTM unit. Unfortunantly, it doesn't fit the old unit's rubber mount. Time to fabricate.

    IMG_0736.JPG

    I started by taping the old mount in place and tracing the new CDI box where I could to get a reference between the posittion of the CDI box relative to the holes in the airbox I want to use to mount the CDI box. Next I blued a portion of 16 gage and traced the lower half of the CDI box. I left a bit of extra sheet to bend then laid the old mount over the sheet and located the mounting holes.

    IMG_0738.JPG

    Cut, sand, drill, bend. Now I need weld on studs. I grabbed some flange head M6 screws of the correct length out of the junk hardware pile. I spun them in the lathe to knock the head down to 1/16" ish and turned the wrench flats off. Now I have studs to mount the CDI to the plate.

    IMG_0739.JPG
    #86
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  7. Z50R

    Z50R Not lost yet

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    Weld, sand and have a go at the wire wheel.

    IMG_0740.JPG

    IMG_0741.JPG

    And installed on the bike.

    IMG_0743.JPG

    Cross CDI mount off the list. Add CDI mount to the list of things to be painted. Go to bed.
    #87
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  8. Z50R

    Z50R Not lost yet

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    So after I made my list and made what seemed like the most straight forward thing on the list, I picked something to think on before I walked away.

    The fuel pump on the 640 Adventure is a straight forward piece opperationally. It consists of a membrane that gets sucked on each time the piston sucks for gas. On the side of the membrane is a chamber with two check valves. Each time the membrane relaxes, gas is pushed out, each time the membrane is put under vacuum, the chamber fills with gas again. This means no electricity is needed for the pump to work and the moving parts are both simple and limited in number making for a reliable part. It also means the pump isn't capable of pumping fuel a great distance. The fuel pump is only necessary for giving the last gallon of gas enough of a head to go up a few inches into the carburetor bowl.

    On the 640, the fuel pump is located under the carburetor and behind the starter motor. There is no space there on this bike. The carburetor is mounted lower and is larger. The thinking starts with where to put it. I settled on a spot under the left radiator. I picked the spot because it will mount inboard enough to keep it from being struck in a tip over while being low enough that the pump doesn't need to draw gas up hill.

    IMG_0745.JPG

    I toyed with mounting options, the plastic dirt deflector is gonna go, I thought about mounting the pump to the replacement but decided that would be inviting a debris strike to take the pump out. I thought about replacing the engine mounting plate with a steel one and welding on some standoffs but the oil line in front of it is inflexable so installing the mounting plate would require removing the oil line and that doesn't sound like fun. A steel plate would do the job but standoffs that long would also add weight where strength and weight are not necessary.

    I settled on the side cover bolts adjacent to the location I wanted to use. Looking at the situation, I realized that with the pump turned around and mounted on the inside, a simple flat plate would do the job and therefore aluminum was an easy choice.

    Step one on this job is figuring out the relationship between the two bolts. This isn't simple since there is engine case between the two. Time for more paperwork.

    IMG_0747.JPG

    This was then transferred to a piece of 3/16" 6061 T6 plate. The screws removed were also replaced with new ones 5mm longer.

    IMG_0746.JPG

    Cut, drill, sand, drill, wire wheel.

    IMG_0748.JPG
    #88
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  9. Z50R

    Z50R Not lost yet

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    And installed on the bike.

    IMG_0749.JPG

    I thought I'd have to drill a vacuum port but Suzuki knew I was coming and did it for me.

    I figured I'd run gas/vacuum lines before any dirt finds its way into the pump.

    IMG_0751.JPG
    #89
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  10. Z50R

    Z50R Not lost yet

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    That project was much easier than anticipated. I had a bit more time so I took another bite and started to chew.

    The choke knob on this bike is a simple affair coming straight out the side of the carburetor. I prefer this arrangement to a handlebar mounted lever for two reasons.

    First, the controls on the bars are plenty crowded with things that are needed while riding, why complicate the bars any farther with stuff you don't need?

    Second, Bowden cables are a good way to transfer mechanical motion down odd paths but the drawback is that they get jammed up with debris and eventually fail. On something that gets used all the time and is well protected like the clutch or throttle, this is less likely and more noticable. On every bar mounted choke arrangement I have seen is a tiny magnet to attract dirt and a funnel to ensure it goes where it is least needed. Water gets in there and freezes too which is hilarious because the only time you really need the choke, it is hopelessly frozen.

    So the choke knob will not be replaced with a cable actuator. Why all the discussion? Well, it can't stay as it is either. With the tank in place, there isn't enough space to pull the knob, it strikes the inside of the tank! I only need about another milimeter but that is enough to warrant change.

    I start by removing the part from the carb.

    IMG_0752.JPG

    I tried making a support out of scrap thinking I could drive the knob off the end of the shaft, shorten the shaft, and reattach the knob.

    IMG_0753.JPG

    This didn't work because the brass inside the plastic has a larger diameter than the shaft.

    I ended up putting the entire assembly on the lathe and gently turning the knob into waste. Only little bites, the plastic is hanging way out on the end of a slender shaft and the whole thing deflects under even a light cut.

    IMG_0754.JPG

    When I was done, I parted the last 1/4" of the brass shaft off. Next I turned a new knob out of nylon round stock but left it attached to the parent material.

    IMG_0755.JPG

    I was thinking about the difficulty of pressing such a delicate piece together when I had an eureka moment.
    #90
  11. Z50R

    Z50R Not lost yet

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    I want a press fit on this knob because I don't have a loctite like substance that can prevent a nylon knob from unscrewing off a brass shaft. Just because it is press fit doesn't mean it can't be threaded though! Ever heard of a nyloc nut?

    So I left the nylon in the three jaw but pulled the chuck off the lathe so that the nylon would run true when I needed to turn it again. I installed the collet chuck and turned some shallow threads in the brass shaft. The goal is only to act as a guide, not to form any kind of strength component. Then I swapped the chucks back and held the brass in a collet attached to the tool post. Using the threading feature on the lathe, I drove the brass shaft into the nylon with a twisting motion.

    IMG_0756.JPG

    Voila, a very tight press fit between two delicate parts! Part the knob off the parent material and the job is complete.

    IMG_0757.JPG

    And installed on the bike

    IMG_0758.JPG

    That is enough for now.
    #91
  12. Z50R

    Z50R Not lost yet

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    This post was incoherent. I'll fix it and post again tomorrow.
    #92
  13. Salsa

    Salsa Long timer

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    Sounds like most of my posts.

    Don
    #93
  14. larryboy

    larryboy Stable genius.

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    I don't think that fuel pump location is going to work. Can you say vapor lock?
    #94
  15. Bigbore4

    Bigbore4 Long timer

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    Agree. I have EXTENSIVE experience with those pumps. Retired from an engine manufacturer. They are dirt simple and reliable as a brick, but sensitive to 2 things. Heat, and oil getting in/on the back side of the diaphragm. We dove ours off crankcase pulses so there was oil vapor.

    Cool build, I am enjoying it.
    #95
  16. Z50R

    Z50R Not lost yet

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    Thanks for the tip, I'll think some more and consider a heat shield or moving it.
    #96
  17. dnrobertson

    dnrobertson Big Bike, Slow Rider

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    That's interesting.

    I have just looked at the location of the fuel pump on my KTM 640, and I would say the relationship between pump and pipe on the 640 is very similar to the Z50R location on his machine. Further, the 640 pump sits on top of the crankcase and would have less air flow than Z50R's re-located pump.

    I'd be interested in real world experience of Z50R's solution.
    #97
  18. Z50R

    Z50R Not lost yet

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    This is why I didn't hesitate too long about putting it there. Every time I screwed with the pump on the 640, I got burned by the exhaust and if the vacuum hoses was too flopy, it'd melt.

    I really like the pretty aluminum bracket I made but I am thinking with steel I could mount the pump at an angle relative to the case and get more space between the exhaust pipe and the fuel hose. A piece of metal at an angle could deflect the heat away and encourage cold air flow too.
    #98
  19. Z50R

    Z50R Not lost yet

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    So I typed an aimless diatribe last night when I should have been sleeping. Lets see if I can organize it today. If you are reading along for the fabrication aspect rather than design thought process, skip this post.

    As I have mentioned a few times before, lighting is on my mind for this bike. I commute quite early in the morning so about 1/4 of my riding is in the dark. I want something street legal and bright that doesn't consume watts. I decided that a 7" round light will be the answer regardless since so many options are available. Going with a 7" round light also somewhat future-proofs the bike since I expect new lighting systems to be manufactured in that size. Even if the bike is scrapped, a good lighting system can be moved to another project.

    I do not want a UJM/Harley looking front end with the stereotypical round bucket held by two stanchon mounted wings and a chrome bezel ring. Nothing more blah in the moto world exists. I toyed with the idea of multiple lamps and asymetrical mounting ideas as are in style right now. I am not satisfied with the fit in the space I have. I keep coming back to the rally raid look of the previous decade or two exemplified by the Baja Designs La Paz (no longer made) and the Trailtech Race Light. I contacted Trailtech about the possibility of buying just their frame. They replied that they'd charge me more than if I just bought their light.

    The more I think about it, the less I want a pre-made frame. I would have no control over size or fork mounts. Further, I would need to spend about $200 on a used light and then trash the light. Instead, I can dump all that money into tooling and come out ahead. Looking at the design, I need two tools that I don't have: a ring roller and a tubing bender.

    Tubing benders are size specific. Small benders might bend tubing of several small sizes with one die. Larger benders have replacable dies but each set cost nearly what a bender cost. Since I am a cheap bastard and I don't see myself buying multiple benders or dies, I needed to pick a tubing size that I can allow to drive design constraints in the future. I picked 1/2" because the tubing is redily available and strong enough for many of my applications. 1/2" tubing is right on the cusp of bender styles, one can purchase a bench or pedestal mounted unit or a hand-held bender in that size.

    I did some digging around the internets and settled on a Ridgid unit that retails for about $110. It is capable of bending mild and stainless tubing up to 16 gage. The reviews are good and I trust the brand. I was hemming and hawing and trying to decide if it was smarter to turn my own dies and make a bender when the exact bender I wanted popped up on craigslist for $40. Sold.

    I haven't addressed the need for a ring roller yet because I can't think of another application for the tool. Part of me says farm that work out. The bender however has two other applications on this bike. I want to replace the plastic deflectors beside the skid plate with steel bars similar to an XR650L's idea of a skid plate. I also want to modify the rear rack.
    #99
  20. Z50R

    Z50R Not lost yet

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    Like any child with a new toy, I immediately bent a scrap rusty tube to see if the bender would kink or crush it or if the tool would brake or refuse to bend. All fears were immediately put to rest as the first bend was perfect despite using less than perfect tubing. I was excited. I chose to screw around with the rack

    I have been using Wolfman panniers since I bought the 640 Adventure; they were used and came with the bike. They are really used now and, while I highly recommended them and they are quite durable, they are showing their age. The 640 pannier racks weigh close to 10 pounds. Each time I installed them, I asked myself why a moto needs a boat anchor. Further, 640 accessories are worth decent money and many people offered to buy the racks off my bike.

    Last year a friend got a Giant Loop Great Basin bag. I was impressed with how well it stayed put and made a mockery of all the other side bags I had seen. I bought one a few days ago for this project. There are a few drawbacks to the giant loop system. First, while much lighter, running with no racks takes away the handholds used to get the bike out of mud holes. Second, the bag jambs your plastics into the muffler. Giant Loop provides a heat shield but really it is an afterthought and an advertisement piece for them. I think I can address these problems by adding small wings to the rear rack.

    The rack from the 640 looks like this:

    IMG_0732.JPG

    Slap a Giant Loop bag on the ass end and the bike looks like this.

    IMG_0733.JPG

    Here's a few shots to show what I am up against:

    IMG_0763.JPG

    IMG_0765.JPG

    The bag sits 2 1/2" forward of the tie point. If I let that happen, the bag will not allow a passenger to ride. This isn't an issue for rallies but if I want to take my wife or daughter camping, this had to be addressed. The wings of the bag rest well on the rack's grab handles but they could use more support.