2017 500 EXC-F and 350 EXC-F

Discussion in 'Thumpers' started by noahr, May 17, 2016.

  1. Zuber

    Zuber Zoob Supporter

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    The 2014-2016 500exc is the real sweet spot. Plain bearing crank should last a long time. Valves don't need much if any adjustment. Doesn't need much to make it run great. Just tweak the TPS, pull out the sink strainer in the stock exhaust and ride.
    enduro16, Watercat, Oldebonz and 2 others like this.
  2. ovlaicu

    ovlaicu Noob

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    Apr 8, 2018
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    Ontario, Canada
    Have you seen the baja design windshield?
  3. ridewestKTM

    ridewestKTM Long timer

    Joined:
    Jun 7, 2007
    Oddometer:
    1,860
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    Mesquite NV
    5th gear Conclusion:
    Review and up date:
    I bought a 2018 EXC 500 in Nov 2018. I noticed first time thru the gears there was a problem. 5th was way to close to 4th and jump to 6th was huge. But I knew before buying the bike that the top to bottom gearing was great. I plotted out the rpm to speed plots per gear and posted it in this thread. I rode the bike for 1/2 yr always annoyed with the glitch. I had figured there was a reason for such a problem, like module (pitch) availability for the ratio and centerline spacing. I began a exhaustive study of modules and ratios and gear numbers (teeth) and etc. But I found no correlation that explained the faulty gear pair. Modules were obviously selected for needed pairs. So the next thing I did is find the best gear pair to fit the gap between 4th and 6th. The best was terribly fine (small module). But in a similar module as the other gears a 24t driving a 23t pair would be nearly perfect. Stock was 23t driving 24t. Could it be that somewhere between design and production they transposed the tooth numbers? I thought so and posted the presumption. From that I learned two other facts; 1. the 2016 EXCs 5th was a 24t driving 23t but was otherwise the same gearing. and 2. The 2017 up SX and XC 5th was 24t driving 24t. The first point supports the presumption of a mistake; why would they copy all but one gear pair? Obviously (IMO) KTM designers were happy with the gearing on 2016 but changed something and oopsed, or the gear manufacture oopsed.
    So I thought; if 2016 is largely the same, could 5th be interchanged? I did a graphical estimation of centerlines. Crude as it was chances of "close" being different was small. Meaning centerlines were likely the same. So I ordered 2016 EXC 5th gear pair, 2018 SX 5th pairs, and Head and base gasket. (I was going to get a better or perfect 5th)
    I got the 2 gear pairs. Right off I measured and determined the centerlines were the same. So what was the change between 2016 and 2017 that enabled a mistake, and why can't I use the 2016. Well the answer to both is the change was to further lighten the bike, the 2017 and up uses narrower/lighter gears and the 2016 gears would not work in 2017 and up. (BTW I also found reliable data that the 2020 KTM and Huskys are unchanged).
    I sent back the 2016 gears, and installed the SX pair. Numbers don't lie, it's a small change, but I am still happy with the outcome. If the bike came with the 24 24 5th I would not have questioned it at all.
    Task:
    I bought the gears and gaskets from RMATV. Main shaft gear 79433005100 $84.57 countershaft 79433015200 $96.95 Head gasket 79430036010 (for 500) $57.87 base gasket 79430035000 $15.38. Flywheel puller 1179010005 $14.99
    Other gaskets and tools at your discretion.
    Tips: No need to remove anything from the clutch side except clutch and if you want the shift shaft. Leave the piston in the cylinder -raise it enough to get at wrist pin and one side is easier than other (right as I recall). Remove cylinder with the piston inside. Small point but I'll save you time; header pipe will not come out until engine moves then on assembly you have to time the replacement of the pipe as you insert the engine. Might try taping/strapping pipe in place just forward of installed position.
    If you don't want to DIY might try Thumper Racing in Gardnervill NV.
  4. Fast1

    Fast1 Twisted Throttle

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    3,511
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    yes I've looked at many different ones.. I'm looking for one that places the shield further away from the triple clamp and is easy to remove when not desired.
    ovlaicu likes this.
  5. Oldebonz

    Oldebonz Been here awhile

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    Nov 24, 2012
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    293
    Location:
    Ohio
    Thank you! Much needed research.Cost not really as much as I thought,as long as you DIY.My 5-6 gap was quite noticeable before GET ECU,Desmog,decork, now just a bit noticeable.
  6. Oldebonz

    Oldebonz Been here awhile

    Joined:
    Nov 24, 2012
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    Ohio
    Revs more easily in 5th,pulls harder in 6th at the lower rpm range.Still thinking hard about the swap now that I know what’s involved and doable! Thank you ride west KTM!
    Bitingdog likes this.
  7. thejrod

    thejrod Been here awhile

    Joined:
    Nov 2, 2010
    Oddometer:
    688
    Location:
    Arlington, WA
    Ok I’m stumped....
    Bike left me stranded deep in the gnar today. Symptom wise, it appeared to be a dead battery. Dash was dead, no fuel prime, not even a click from the starter. Just dead. Wouldn’t take a jump start. Main fuse was ok. Battery showing +13v at the terminals and at the frame (so unlikely the ground strap). Bump-starting would get it to fire, but it ran like crap, sputtering and surging, before dying seconds later.
    A bad alternator or even reg/rect would still allow the starter to turn over.
    A bad starter relay wouldn’t make it run terribly from bump-starting.
    Is there another fuse or breaker in the system?

    ‘17 350EXC, desmogged, JD tuner. No issues in 90 hrs. I guess I’ll start isolating things like the tuner and see what happens.
  8. ridewestKTM

    ridewestKTM Long timer

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    Mesquite NV
    Good description. I can't say I have an answer but checking voltage tells you nothing about current. Even one ohm of resistance can fail systems. Check the ground again even volts across the connect.
    Good luck
    horosho and keepshoveling like this.
  9. Brown3690

    Brown3690 Adventurer

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    Apr 11, 2019
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    Location:
    Greenwood, IN
    Take a look at this video for something to try. This guy is difficult to understand sometimes, but he has useful info.




  10. thejrod

    thejrod Been here awhile

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    Arlington, WA
    Good point, and I double checked the ground just to rule it out. That was totally the culprit. Could’ve been a Trailside fix, had I had the wherewithal to actually check it. I’ve literally given that same advice to half a dozen people too.
  11. Zuber

    Zuber Zoob Supporter

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    West of the West, Oregon
    The worst bikes for bad grounds were the 450/505 XCF/SX. This bike ran a battery ignition because the generator was too small to provide ignition power (?). It also became a Duner's bike in later life. AND it had a very small battery. The voltage to the ignition had to be a minimum of 8v or the ECU would just give up.
    In Oregon, Dunes = Salt and corrosion. There would be a slight voltage drop across each connection from the battery negative to the ECU ground. 1. battery negative 2. frame ground 3. sub-frame (aluminum) to main frame (steel) 4. frame ground near coil 5. ground connector to ECU. Cleaning each one helped, but didn't remove them. A ground wire removed a lot.
  12. WIsixfitty

    WIsixfitty rock and roll the bones

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    west of road america
    I did a little more test research to combat swingarm/shock knuckle wear.

    I ditched the metal/Ti plate idea as the adhesive I used just didn't get a good bond. Hindsight maybe silicone sealant would work.

    Anywho, instead of going with the super heavy-duty velcro stuff I tried the el-cheapo stuff everyone has laying around. I did another 350+ miles of wet sand with tons-O-puddles with pretty darn good results. So if you have some in shop/house/tote put it on. It works! It's probably good for another 350 miles. When it wears out I'll slap some new on.
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  13. WIsixfitty

    WIsixfitty rock and roll the bones

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    I ditched work late last week for one last ride (on dirt for the season). :brow

    I had to travel 2 hours north to find bare dirt. Everything south had that white crap all over the place.:bluduh

    Starting temps were about 25* and dropping. I made it 2 hours before the fingers and toes went numb. I couldn't figure out why my knobbies were humming like I was riding on pavement. Umm... I was. The ground was frozen solid. :jump After losing both ends rather abruptly I backed it down a bit. Frozen sand is slippey.

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    No nice knobbie tracks in this sand/ice.
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    After last summers tornadoes, the (federal) camp site clean up crews got creative. :thumb
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    It's now official ice riding prep time.:ricky
  14. MAXVERT

    MAXVERT O.G. on da O.C.

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    Baja Arizona
    Nice timely info I'm in Mexico and looking for a bike to have in Durango Mx. An amazing Backcountry riding area.
    How about the 450's if that's what I can find.

    Max
  15. Zuber

    Zuber Zoob Supporter

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    Lots of FE450 Huskys, but a rare few 450EXC's, only available in the ISDE edition until recently. The 500 is exactly the same weight with a little more mid-range. The 450 does kick ass and rev's a 1000 rpms more.
    MAXVERT likes this.
  16. MAXVERT

    MAXVERT O.G. on da O.C.

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    Location:
    Baja Arizona

    Don't need the EXC's in Mexico so the xcw's
    should work fine.

    Max
  17. andrewgore

    andrewgore Gôremā

    Joined:
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    18,130
    Location:
    brrrrrrlington
    After a ~2 year hiatus from my last 350......, I'm back on one :thumb
    IMG_20191115_193750.jpg

    Gonna be a long winter.
  18. cmbthumper

    cmbthumper Been here awhile

    Joined:
    Sep 29, 2018
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    367
    Location:
    Ramona, CA
    As I save up for my Baja Design/ Motominded headlight, in the meantime I wanted to use my spare ADVmonster Model 19 lights on my KTM 500. I had trouble figuring out how to mount them and asked sanjoh in his ADVMonster thread https://advrider.com/f/threads/led-auxiliary-lights.607184/page-261

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    Tried to bolt the stock mounting plate to the existing unused hole on my Highway Dirt Bikes Handguards but that was a no go as they pointed towards the center. Put my thinking cap on and here is what i came up with. I had a bunch of these parts left over from trying to figure out my phone and GPS system. Only thing i had to order was M10x1.25 Nuts. Ram 1" Ball with 1/4-20 female installed on to the HDB hole, 2.5" Ram clam shell, Ram 1" Ball with M10x1.25 thread attached to the ADV Mount. Near infinite adjustment. Straight ahead, Side, Down if in rock gardens etc etc. Since it is temporary i will just run it off of a 4S battery for now instead of putting the whole harness on. I will give it a test in a few weeks when my doctor releases me to have fun from surgery.

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  19. DIRTLER

    DIRTLER Long timer

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    Great idea!
    cmbthumper likes this.
  20. bigborefan

    bigborefan Making new friends

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    USA - Midwest, Central Illinois

    Welcome back Andrew. I remember your posts