1989 KTM 350MX/EXC

Discussion in '2 smokers' started by Ajacklee4, Feb 13, 2021.

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  1. Ajacklee4

    Ajacklee4 The Young Old Guy

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    Can anyone tell me about the 1989 KTM 350 2 Stroke? I've heard it called the 350GS, 350MX, 350EGS, 350EXC, and 350MXC. Can't find any real info on them online, from actual power numbers to weight or parts interchangeability. I have one and am looking to restore it, any help is appreciated. Got mine for a steal.

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    #1
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  2. Spikester300

    Spikester300 Roll Tide!

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    A friend I used to ride with had one the first year they came out, great bike. I don't think they made a MX, either a MXC or EXC enduro with lights. They were smooth with a lot of bottom end, I think the '89 like you have had more top end power. Parts may be hard to find now, good luck with it, great bikes.
    #2
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  3. 380Viking

    380Viking Adventurer

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    Many parts interchange with 500s of the day, some with the 250. I still have the 85 250 I bought new and use it regularly. I rode a couple 350s back when they were new and found them to be a very nice ride, KTMs of that era are a nearly forgotten gem. Suspension can be made very supple, the power is strong and friendly, yours is new enough to have decent brakes and they are light and nimble. Make Ebay your friend.
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  4. Foot dragger

    Foot dragger singletracker

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    Those were the struggling years for KTM,management problems etc. Luckily they snapped out of it.
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  5. 380Viking

    380Viking Adventurer

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    It wasn't just luck
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  6. Foot dragger

    Foot dragger singletracker

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    You mean KTM coming back from very nearly dead?
    Their bikes from mid to late 80's and into early 90's were not that well received,Ive never seen one in person around here. That was when I raced Yamaha's.
    In 1996 I bought a new 300 EXC and have had KTM's ever since. And had a 1977 GP 250/1979 420/495 twin shock earlier.

    The 96 300..............cool bike but un-jettable. I rode it for over 2 years it never ran the same 2 days in a row,piles of needles and jets went through it.
    The forks self destructed internally,many small parts broke repeatedly. But a cool bike anyway. Then I had a 2000 300 MXC and it was totally reliable,and fast,and had handling harsh suspension issues but not horribly bad. Sold it bought a 2001 200 and loved it.
    Had many KTM's since and all were solid.

    KTM came pretty close to going out of existence at one point.
    The CEO these days has a truly world view of KTM and the marketplace.
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  7. Ajacklee4

    Ajacklee4 The Young Old Guy

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    It's really interesting to hear most people have nothing but praise for these older 350s and 500s. I wonder why they never really caught on? Do any of you have photos of the 250, 350, or 500 from '89 during a race or event? Or any neat race or enduro videos?
    #7
  8. Foot dragger

    Foot dragger singletracker

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    KTM almost went out of business ,early/mid 90's maybe,not sure. They had sorta lost direction.
    Mid 80's KTM's and the years after, you just dont see them around, KTM was sorta trying to copy japanese bikes.
    In 1998 KTM completely changed their MO.
    Mostly all new bikes from head to toe. And have been going radically upwards ever since.
    #8
  9. 380Viking

    380Viking Adventurer

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    They were fairly common around here (western Washington state) in the day amongst enduro and hare scramble types. I don't have any pics or vids though, but lots of stories. The spare parts thing got really tough as KTM went through their troubles and many were abandoned. As the internet ramped up and especially Ebay became a thing you could find parts and solutions if you were still interested. I have two from those days, my 85 250 that I bought new and an 85 500 that I got after my brother fell into a river and hydro locked it and then let it sit wet and bought a Suzuki RMX instead. We revived the 500 for my son when he was in high school and he rode it a couple years. The 500 mostly sits now as I don't have the muscle to kick it anymore. It is really nice including a rear disc brake which is a huge upgrade on the monster. I have focused more on my 250 which is an easy starter and it now serves by being set up for packing my chainsaw for trail clearing days though sometimes I take for less serious days when I have youngsters in tow as it is better at a slower pace than my 380. The 250 was revived when I realized I could make pistons from 91-94 KTM 250s work with some modifications and it was much improved when I fit up a rear disc from an 86 and a front disc caliper from an 87. Those upgrades are all thanks to the internet, otherwise the bike would still be in boxes in the back shed. I think an 89 350 is very much worth doing, the biggest challenge maybe pistons but solutions are out there. Good luck!
    #9
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  10. Blazz

    Blazz Stationary Traveller

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    Hi there.

    It’s like Viking wrote, 350 and 500 2t shared many parts incl. the same engine cases (different crankshaft however and obviously piston+barrel/head) the 250 line had major update in 1990 but 350/500 remained almost unchanged till at least 1992.

    engine code for 350 was 555 (bore/stroke 75/78mm) and for 500 it was 565 (bore/stroke 80/80mm)

    If I remember right even first LC4s were designed designed based on those engine cases.

    below is some basic data on 1989 line

    Exc is what You would call enduro bike- same as nowdays, EGS was little bit more civilized , what You would call a dual sport now ;)

    [​IMG]
    #10
  11. Blazz

    Blazz Stationary Traveller

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    Not quite ‘89 not even original ‘92 but You’ll get the idea along with some history of the five hundred ;)



    Pretty sure 350 were more popular in enduros back in their days. Six days is the place to look for- in 1989 it was held in Walldurn - (then) West Germany- In the vid below you should see something You look for ;)

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  12. Foot dragger

    Foot dragger singletracker

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    A local shop here in Chico has about 2 of these 350's mostly sitting in parts. Ive tried to figure out a deal and buy them, but a customer left them there years ago and they have become static since. I know people could use the parts to keep their bikes going.
    #12
  13. Euromad

    Euromad Been here awhile

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    The KTM 350's were well loved in the Eastern enduros and hare scrambles. Very good motor. You can always update the brake calipers if you want modern pads availability. I saw plenty of 92, 93 KTM 250's when racing then. By 92 KTM got theri shit together and made excellent woods bikes. I raced a 93 300 and it was a very good bike. Look for KTM Facebook pages. they will have the best part sources. You may have to search for European part sources.
    #13
  14. Foot dragger

    Foot dragger singletracker

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    They didnt sell those years in the US much,the magazines mostly panned them.
    The 96 300 I had,I really wanted it to work,and it did sort of. The Marzocchhi forks would self destruct internally if ridden hard,like in 2 rides the bushings would frag and the parts would stick in the magnesium legs. The valving would fill with crap and then zero damping.
    Probably rebuilt them 5 or 6 times. Complete rebuild not just seals. Riding MX killed the forks.

    I made a device to polish the insides of the magnesium legs,which did help with longevity. The rear Ohlin's worked really good with a stiffer spring.
    The jetting was different every day,either pinging or loading up,but I never gave up. ................. Old 300's were well known for this, the older the worse they were. People tend to not remember it now.
    All the small parts,exhaust mounts,bits and pieces in general wore out fast. And were all about 35.00 each.

    But I liked the bike anyway,rode it for 3 years I think. The 2000 300 was rock solid,then I bought an 01 200 and really liked that bike.
    Nothing broke. Nothing has really broke on all the KTM's Ive had since then.
    #14
  15. Euromad

    Euromad Been here awhile

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    I had a 93 300, a 96 360, a 2000 300, a '06 450 and a 2012 300. From the 93 on the KTM's were very reliable. In the end the Orange got annoying to me so I went back to Huskys. I did not have a problem with the Marzoke's fork legs. I liked them. I used them for trail riding, and racing in the Northeast.
    #15
  16. Foot dragger

    Foot dragger singletracker

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    The Marzocchi's I had worked great,really good,till they lost all damping due to internal fragmentation. They didnt like to be ridden hard on a track,I think hard landings killed them.
    There was a reason they quit using them. The lower legs cracked apart around the axle when they got old.

    The bike would start trying to flip over backwards on jumps when the damping went away and time to rebuild again. I spent so many hours on that 96 300 patching it back together it was like a 2nd job. Pipe cracked apart a lot.
    But I had always wanted a new 300 so I kept at it for some years. Starting in 98 they were a whole new bike,the 2000 I had was a beast and unbreakable.
    Same for every KTM Ive had since.

    I remember the forums and the "300 KTM jetting" that went on for ever and ever,special needles,cut slides,different carbs and pipes.
    Eventually KTM made the bore/stroke to fit just the 300,which maybe helped with jetting.

    The dumb ass SEM ignition probably had something to do with it,maybe. The SEM stator cracked apart on a SC 620 I had,not a cheap fix.
    The SEM flywheel crapped out on my 96 300,also not a cheap thing. Once KTM went japanese on ignitions they were on their way.

    The WP suspension had some crap years especially with PDS but it was reliable,some didnt notice,it always felt harsh in tight woods up to 2007 then they fixed it with re-designs.
    My 2014 300XCW worked right out of the box,soft suspension but workable.
    #16
  17. shinyribs

    shinyribs Thumpers for life

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    My first bike was a '87 125MX. A bit of a handful to learn on in the woods, but I was a kid, so it was all good. When I was 15 (1995) I got a '93 125 EXC. Man, that bike was so much easier to ride. I loved that bike! Original owner dropped it in a creek, got hurt and left the bike laying. Insides of the engine were rusty by the time he got back to it. I got it cheap, replaced the rusty bits and felt like a boss with such a new bike! Within a year it needed a piston and none were available. Ended up selling it off cheap. Parts availability was truly random back then.
    #17
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  18. Scott1993

    Scott1993 n00b

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    Some good info in this post, thanks. I recently purchased a 1989 KTM MC 350 EXC to restore, needs ignition diagnosis (no spark) and cosmetic updates. My question is this. Will a bigger fuel tank (baja tank??) from a 1989 KTM 350 MX bolt on my EXC? I like the looks and the added fuel capacity. Thanks in advance.

    Scott
    #18
  19. Blazz

    Blazz Stationary Traveller

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    If it’s the same era - preatty sure it will fit.

    Those days differences between Exc and mx were the wiring harness, ignition, and rear wheel dimension. Frame was basically the same. If You have a bigger (probably 12 liter) tank it most likely came from enduro bike (Exc) or Crosscountry (D-xc) or dual sport version (GS) as MX version had smaller (around 7 liters) tanks stock

    here’s how it looked like in 89 (never mind 250 decals - they were all the same 250/350/500 back then)

    [​IMG]


    P.S. On the ignition- Your model should have either 6V Motoplat or 12V Sem. If it's SEM my bet would be the stator- any moisture that could get into the coils in the stator creates rust that destroys the winding in there but can also be the ignition coil.
    Common problem with SEM ignitions unfortunately. Have no much experience with Motoplat however.
    #19
  20. Foot dragger

    Foot dragger singletracker

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    Once on my 300 the case or a vent let dirt/mud get inside the flywheel. I just took the flywheel off and cleaned and lightly sanded it cleaner and the bike worked again. SEM flywheel/ign. Later the stator cracked and died.
    The more modern Kokusan ign KTM went to has been bullet proof.
    #20