KTM 620 rebuild/refresh

Discussion in 'Thumpers' started by gravityisnotmyfriend, Feb 28, 2013.

  1. gravityisnotmyfriend

    gravityisnotmyfriend Long timer

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    I’ve got a couple of threads splattered about on this bike, and I’m just looking to consolidate everything in one place I’ve restored vintage bikes and vintage snowmobiles on other sites and really enjoy going back the the threads and re-reading my projects.

    So, anyway – the bike. I found a ’94 KTM 620 EXC for sale late last summer. I could tell it had been ridden hard and put away wet most of its life – but after a test ride, I just had to have it!

    Here’s how it looked when I bought it:
    [​IMG]

    I got it for a price I was happy with and spent last summer/fall riding it and making a list of what it needed. I’m glad I didn’t have this list when I test drove it – I may not have bought it!

    So here’s where I started:
    Headlight – flickers
    Tail light – doesn’t work
    Turnsignals – sometimes work
    Instrument lights – don’t work
    Parking light – doesn’t work
    Rear shock – shot
    Front shocks – leak
    Clutch – slips
    Spark plug – needs replaced
    Waterpump – needs new seals/bearings
    Carbs – jetted too fat
    Seat – I hate the white seat
    Plastics – plain white
    Luggage – none
    Handlebars – too low
    Steering - spooky at highway speeds.

    Updates on the next post.
    #1
  2. gravityisnotmyfriend

    gravityisnotmyfriend Long timer

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    The shock is fixed. Bought a used one off an inmate in good shape.

    Initially, I thought I could just pull the two bolts holding the shock on and slide it out the left hand side of the frame. No such luck. I ended up stripping just about everything off the top and back of the bike to get access.

    [​IMG]


    That was taken after I got the new shock in.

    I haven't had a chance to test the new shock. Since I had the tank off, I decided to tackle the water pump rebuild. And, since I was buying parts, I decided to buy a new sprocket shaft seal as well. I'll get some pics as I go.
    #2
  3. MartinPetren

    MartinPetren Swedish Adventurer

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    I love these kind of threads :-)
    #3
  4. gravityisnotmyfriend

    gravityisnotmyfriend Long timer

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    Oddometer:
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    Headlight – flickers
    Just a loose connection.


    Tail light – doesn’t work
    Handlebar wiring was redone - poorly


    Turnsignals – sometimes work

    Instrument lights – don’t work

    Parking light – doesn’t work
    Parking light deosn't exist. Need to buy a replacement.


    Rear shock – shot
    Replaced


    Front shocks – leak

    Clutch – slips

    Spark plug – needs replaced

    Waterpump – needs new seals/bearings

    Carbs – jetted too fat
    New jets ordered. 195-170MJ; 52-45 idle jet.


    Seat – I hate the white seat
    Painted with vinyl interior paint. Not lasting very well.


    Plastics – plain white

    Luggage – none
    Luggage rack built. Top box acquired - but I need to mount it.


    Handlebars – too low
    Rotated back too far. Moved them forward and I think It'll wor
    k.

    Steering - spooky at highway speeds.
    Steering stem had too much slack. Tightened her up.
    #4
  5. Seikkailu_R

    Seikkailu_R Been here awhile

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    Oddometer:
    870
    Location:
    Piikkiö, Finland
    Shock drops down thru swingarm after links are removed...
    #5
  6. gravityisnotmyfriend

    gravityisnotmyfriend Long timer

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    Not in my garage it doesn't! To hell with that easy fix nonsense! I gotta take the hard way out!!!

    I looked at that. I looked real close and decided that there was no way the shock would slide through the swing arm. Not with the nitrogen reservoir on the side. I was sure that if I too the linkages off, it would just frustrate me and I'd have to take the subframe off anyway.

    Well, I've learned something. Next time - if I have to rebuild this one- I'll try the easy way!
    #6
  7. Seikkailu_R

    Seikkailu_R Been here awhile

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  8. CSF

    CSF Been here awhile

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    Nice bike, good luck with the rebuild. Looks great so far. Painting a seat seams like a terrible idea, like something someone would do to make the bike look pretty to try and sell it for top dollar.

    Any chance you could post some larger pics?
    #8
  9. bmwktmbill

    bmwktmbill Traveler

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    Grav, Get a bible you disbeliever....

    Loosen the shock, work the swing arm up and down, up and down slightly turning the shock.

    It will come down fast and go back up the same way.

    It will fall out and smash your finger because you are not ready for that.

    Practice.

    I think the pivot can stay?

    You can adjust the spring tension with the hook on your axle wrench but you must remove the shock to do it.


    Practice, KTM, Paris -Dakar winner.
    bill
    #9
  10. Seikkailu_R

    Seikkailu_R Been here awhile

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    Or just loose top adjuster nut and turn spring with hand...
    #10
  11. gravityisnotmyfriend

    gravityisnotmyfriend Long timer

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    yeah, I've come to that conclusion myself. The seat was recently recovered by the PO. The vinyl is in great shape - so it seemed silly to rip it off and reupholster it. I found this Duplicolor product that is marketed to repaint vinyl seats:

    http://www.duplicolor.com/products/vinylFabricCoating/

    For a $4 can, I thought it was worth a try. Mostly, it worked. But, there are places that the seat cover folds over itself when I sit on it. The paint has come off those parts. So, it was worth a try, but I'll probably end up having a professional recover it - just not white.


    Here's what it looked like for a couple of months after painting the seat:
    [​IMG]

    The picture thing is a bit annoying. Photobucket has been resizing my pics. I may have to look at host my pics somewhere else.You do know you can click on them to make them a little bigger, right?
    #11
  12. gravityisnotmyfriend

    gravityisnotmyfriend Long timer

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    I've got a shop manual for the bike. Sometimes I'm just not smart enough to open it. I've been turning wrenches on bikes since I was 9 years old and I bent an intake valve on my CT70. Apparently I was under the impression I knew what I was doing! In all fairness, I did get the shock off and the new one went in really easily! But, then I just had all that stuff to put back on.

    I'm just going to chalk it up to getting to know my bike! Lessons learned!
    #12
  13. gravityisnotmyfriend

    gravityisnotmyfriend Long timer

    Joined:
    Jun 1, 2012
    Oddometer:
    2,176
    Location:
    ((kg*m)/s^2), IA, USA
    Turnsignals – sometimes work

    Instrument lights – don’t work

    Front shocks – leak

    Clutch – slips

    Spark plug – needs replaced

    Waterpump – needs new seals/bearings

    Plastics – plain white

    Headlight – flickers
    Just a loose connection.


    Tail light – doesn’t work
    Handlebar wiring was redone - poorly


    Parking light – doesn’t work
    Parking light deosn't exist. Need to buy a replacement.


    Rear shock – shot
    Replaced


    Carbs – jetted too fat
    New jets ordered. 195-170MJ; 52-45 idle jet.


    Seat – I hate the white seat
    Painted with vinyl interior paint. Not lasting very well.


    Luggage – none
    Luggage rack built. Top box acquired - but I need to mount it.


    Handlebars – too low
    Rotated back too far. Moved them forward and I think It'll work


    Steering - spooky at highway speeds.
    Steering stem had too much slack. Tightened her up.



    The current project is the water pump. I got the new bearings in the mail from VXB yesterday. The new seals and Orings are coming from KTM-Parts. Hopefully soon. I'm getting some new jets in that same shipment as well as the Sprocket Shaft seal.

    Not much I can do until the parts get in.

    Any advice on getting that sprocket shaft seal out? I've got the sprocket, and spacer out. I'm just not sure how to attack it from here. Do I need to break down and buy a seal puller? Is there a substitute that I can use without risking damage to the case?
    #13
  14. bmwktmbill

    bmwktmbill Traveler

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    #14
  15. gravityisnotmyfriend

    gravityisnotmyfriend Long timer

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    Brilliant! That's exactly what I ended up doing. Bent the tip of an old screwdriver, grabbed the end with a big channel lock, and tapped on the channel lock while working around the inside perimeter of the seal. Now, I just gotta wait for my new parts to get here.

    In the mean time, I've started digging into my instrument panel lights. The bulbs all appear fine - which means the wiring is hosed. I already had to fixed some botched wiring to get the tail light to work, looks like I gotta dig out the wiring schematic again.

    I wouldn't be too worried about it, but I want to know if the bike is overheating. Especially since I'm going to be messing with the jets.
    #15
  16. gravityisnotmyfriend

    gravityisnotmyfriend Long timer

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    Here's a pic of my slap hammer concoction:


    [​IMG]

    It aint' pretty. And it don't work real well. But it worked and it was pretty much free. I got the old seal out without damaging the case.

    So, on to the electrical. I hooked up 12V DC to the bike to simulate it running and tore the front end apart to diagnose why the lights don't work in the instrument panel:

    [​IMG]



    Turns out that 3 light bulbs were burned out, one had fallen out of its socket and one was missing. That left two bulbs that weren't burnt out. I plugged them into various sockets and whaddya know? The electrical is fine! I just gotta order some new bulbs.

    And, I figured out the turnsignals. The flasher relay is physically crushed. The outer case is broken. If you hold it just right it'll work, but sometimes it doesn't. It just needs replaced.


    So, here's the real exciting part. The bike is as dismantled as it's going to get. As soon as my parts get here, I can start putting her back together! Up until this point, I've left the bike in worse shape than she was before I started - every night. Now, it's going to look like I'm making progress!

    I really wish it were warm enough to take this carcass to a car wash. She's sorely in need of a pressure washing!
    #16
  17. bmwktmbill

    bmwktmbill Traveler

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    Grav,
    Nice work. Nice tool.

    I think there is a silicone O-ring that works with the spacer/seal surface.
    Be sure to replace that.

    At least there is on the '02 Adventure.
    bill
    #17
  18. gravityisnotmyfriend

    gravityisnotmyfriend Long timer

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    Thanks!

    Yeah, I've got the O-Ring coming with the rest of the KTM-parts.com order. Creeper's write up covered that in detail.

    It looks to me that the chain was set way too tight and that's why this seal was leaking. I just hope it didn't do any real damage to the bike.
    #18
  19. bmwktmbill

    bmwktmbill Traveler

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    That's so common. If there's no play in the shaft things should be good.

    You can keep n eye on it.
    Do you have a cush hub?

    That might help.
    b
    #19
  20. gravityisnotmyfriend

    gravityisnotmyfriend Long timer

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    I didn't notice any play - but didn't look for it either. I'll give it a good look tonight.

    The shop manual sure makes it look like I have a cush hub. The Austrian translation of dämpfergummi is "drive rubber". Close enough!

    Most of my parts came in yesterday. Hopefully I can get some time in the garage tonight to start putting her back together. The only thing I don't have are the bulbs for the instrument cluster. I've found them in a few places - but I can't get my 4 itty bitty 1000 hr incandescent bulbs for less than about $30.

    I can either order them from China in packs of 10 for $.50/piece and pay $30 shipping or I can order them from Cheap Cycle parts for $4/piece and pay $10 shipping. Either way feels like a rip off! The same bulb is used in some Yamahas. I'll see if I can find them that way. Maybe there's a dealership that carries them around here.

    I'm really considering converting the whole mess to LEDs. It wouldn't be any cheaper - but at least I'd never have to replace burnt out bulbs.
    #20