500 EXC Engine mod options, pros/cons?

Discussion in 'Thumpers' started by luke!, Sep 16, 2020.

  1. luke!

    luke! Adventurer

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    I have a 2017 500 EXC. I recently put supermoto wheels & tires on it and currently use it mostly on pavement. I also use the bike for trail-riding and I'm planning to get wheels and tires for dune riding as well. I haven't really seen much about engine upgrades beyond intake and exhaust. I am planning on a MULE GET or a Vortex ecu, possibly pulling the intake reeds, and a pro moto billet end-cap for the exhaust ( I kind of like how quiet the bike is, I don't necessarily want it to be super loud ).

    I see there is an aftermarket camshaft available from Daniel Crowe Racing [​IMG] which claims
    Having never upgraded / changed camshafts on a bike before, are there any drawbacks to putting an aftermarket camshaft?

    As far as big-bore kits, last time I emailed Thumper Racing they said they "have a billet cylinder 550 kit for the 17+ 500’s in either stock or 14:1 compression", and said they are also working on a much larger displacement kit. And I believe there are different pistons available for the stock cylinder which increase compression.

    I enjoy being able to fill-up at regular gas stations, not sure if I want to be tied to keeping race-fuel on hand but trying to stay open minded. What would you do to your bike for performance upgrades if you were willing to spend around 3 or 4000? Is head work advantageous for this engine?
    #1
  2. OrangeYZ

    OrangeYZ Long timer

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    Because unlike 350s, 500s are plenty fast as fuck for most people!

    Whenever I feel like scaring myself I open the throttle more than 1/3 and that usually does it for a couple of months
    #2
  3. bemiiten

    bemiiten League of Adventures

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    Mechanical power mods that would lend themselves to turning the EXC into a faster, expert level supermoto track bike will likely destroy the rideability of the EXC offroad.
    #3
  4. Kaaden

    Kaaden Been here awhile

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    That DCR cam will move the power up into the mid-high range.
    Headwork is advantageous but $$$
    Big-Bore is advantageous but $$$

    99% of making the 500EXC an amazing supermoto has nothing to do with the engine aside from the Cam making proper power in RPM's that street riding will encounter.
    It has everything to do with changing up the suspension/steering geometry/braking/ and a slipper clutch.

    Spend that 3-4k on a full revalve of your suspension/16mm Offset Triples/Beringer or Brembo retrofit / and a Suter Slipper Clutch.

    On the roads i ride i can reel in Superbikes/Naked with ease and just pace them all day and the only way i can get to the last 25% of my tire profile is on a go-kart track.

    Notice all those mods kill your dual-sport/offroad ability as noted by @bemiiten

    Also with the money i spent on my 500EXC i could of just got a 2019+ 690SMC and a 500EXC and keep it stock.
    So are you really committed to this uber-motard or?
    #4
  5. overlander

    overlander Gravel Travel Tours Supporter

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    If you really want the bike to be a lot faster install an off road only ECU and take some high performance rider training!!
    #5
  6. timeOday

    timeOday Long timer

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    I have a different take, if you want a streetworthy dualsport with POWAH then don't do a bunch of spendy iffy aftermarket mods to a 500,
    just get a 690/701, you can't miss.
    #6
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  7. AUSSIEADV

    AUSSIEADV 2wo left foots

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    Lol ask for engine performance upgrades and you get everything but!

    You dont need to spend big on the GET or Vortex. The JD tuner will suffice. Reeds removed and an AM muffler or mod the OEM. https://ktmtalk.com/showthread.php?535125-12hp-Increase-2017-FE450-450EXC-with-Simple-Mods-Closed-Course-Race-Setup

    A
    correctly fitted big bore kit and cam should not reduce engine longevity. Dont run 14:1 comp. Typical 12:# will do. A performance cam in a big bore will work a little lower in the rev range also the big bore will have more torque. Yes port work if the budget allows. I do my own. Make sure the bike has plenty of breath ability.
    #7
  8. Navin

    Navin Long timer

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    The Thumper Racing 610 kit and 570 cam in my 530 just made it better everywhere. More torque, more linear power, and it ran like a true big thumper. He has a all new to him engine apart and is building it for me now. GPX FSE250R. If its coming out of Travis' shop, its good stuff.
    #8
  9. Bitingdog

    Bitingdog That's not my dog

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    Why don't you start with the easy & cheap stuff first? Yank the stupid reeds, remove stock end cap screens, and Vortex/GET ecu or JD Tuner.

    It's a dramatic difference, and has the added benefit of making your bike's power delivery better off road too. More linear response, tremendous low rpm grunt, and it will eliminate any flameouts when chugging up obstacles.

    You might find what you're looking for.


    A stock 500exc is meh, but they're damned fast when dialed-in
    #9
  10. jm19328

    jm19328 2020 KTM 500 Exc

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    The high compression piston will be hard on your crank and rod bearings. Also you'd have to run a splash of race gas or octane booster probably to prevent detonation.

    I`d get the most power out of the stock bike first then re-evaluate, pull the reeds, add a tuner and open up the exhaust
    #10
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  11. motometal

    motometal i like motorcycles

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    Regarding big bore, I sure wouldnt want the bike to vibrate more than it does already.
    #11
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  12. AUSSIEADV

    AUSSIEADV 2wo left foots

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    Not all big bores do. People need to research before making assumptions.
    #12
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  13. peman

    peman Been here awhile

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    Hi Navin, can you tell about the 610 kit and the cam? i have a 530 and it will be my last off road bike so i want to bomb the crap out of it, i have two spare motors to make this happen with, how does it compare to stock? is it financially worth it? i sent an email to thumper racing and got no reply which is disappointing as i was looking at ordering from them the big bore kit, i didn't see a cam on their website is it from them? i was told by a cam shop that you can't weld the cam and reface it but you can regrind and reshim it, i have a spare cam with a cam shop to see what they can do, any info you can share would be appreciated.
    #13
  14. motometal

    motometal i like motorcycles

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    I did not say it would. My statement was purely an opinion/observation. Some don’t, but that means some do.
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  15. AUSSIEADV

    AUSSIEADV 2wo left foots

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    Speak to TravisD37 by PM over at KTMtalk.com. Hes Mr Thumperracing. Also going through that forum will give you a 10% discount. No, they dont respond to emails.

    The KTM 610 should basically be the same as my Husaberg 610. If that is the case they are a torque beast. My FE570 has been opened up and fuelled but its not a patch on my 610 but my 610 has had the head ported. The CP piston kit is considerably heavier than the OEM piston kit. I removed material off the piston and used a lighter Wossner wrist pin.

    Speak to Travis about the cams. They used to do them, stopped, then i saw Travis post recently that he has started doing cams again. It can be an expensive exercise if you need to buy a later cam for the treatment. He will be able to advise.

    “Financially worth it”. Thats up to you. When i get back on my feet i have the parts and engine here to build another.

    7581A1B5-9A14-4C7E-94D2-D9A5CA6C03AF.jpeg 59434169-D931-470B-B674-C4893EC7339D.jpeg
    #15
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  16. AUSSIEADV

    AUSSIEADV 2wo left foots

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    Navin, ive only just noticed what you wrote above. The 570, 530 and early 500 OEM cams are the same.
    #16
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  17. Navin

    Navin Long timer

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    Its been a near a decade but Im sure we did a "570" cam too. Maybe it was reshaped at Thumper but I thought it was the Berg part.

    610 was totally worth it. Engine was smoother, endless flow of torque, there was no downside.

    It can take awhile to get a reply. I think they are jammed packed with work.
    #17
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  18. AUSSIEADV

    AUSSIEADV 2wo left foots

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    Gotchya.
    #18
  19. afordableperformance

    afordableperformance Been here awhile

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    Back in 1997 when Thumper Racing was in Marshall, TX I brought my XR400R to them for the works; suspension, 440 kit and pumper carb. I'm pretty sure Travis was there too, did awesome work. Results were amazing and worth every penny, it was great bike until the KTM FRS bikes came out. In 1999 I brought them my XR650L for a 675 kit and the results were noticeable, but I don't think it was worth the effort and cost.

    I think the KTM would fall into the XR650L category, its already a lightweight powerhouse and if I had a 2017 model, other than the reeds and maybe ECU update, my first change would be to throw in an older 5th gear! Otherwise, like most projects it could become a bottomless cash pit.

    I myself have assembled many bikes over the years, numerous big bore kits and stroker cranks, but I trust Thumper Racing and their labor rates were reasonable enough for me to take my bikes to them when they were in Texas so I didn't even have to get my hands dirty! They are a bunch of great guys!
    #19
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  20. AUSSIEADV

    AUSSIEADV 2wo left foots

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    Um, did you read the previous posts?
    #20