KTM/Husky/GasGas TPI Fuel Injected Two-Stroke Owners Thread

Discussion in 'Thumpers' started by Lager Meister, Mar 31, 2018.

  1. thejrod

    thejrod Been here awhile

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    I’ll write up a better review when I have more time, but I tried the TBI conversion for ~20hrs, and just removed it to go back to TPI.
  2. Bitingdog

    Bitingdog That's not my dog

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    Oh man, please don't tease us like that!

    Give us the gossip
  3. adv_sacrifice

    adv_sacrifice Been here awhile

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    Ah yes jrodicus right?

    Figured its worth a try at least. I just want to remove the oil tank, lol. But not the end of the world if it doesnt work

    might save oil pump costs in the long run? or a wash with extra oil use.
    thejrod likes this.
  4. RideFreak

    RideFreak Torque Junky

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    With the prices of oil it's likely cheaper to keep the pump on even with it's 80hr replacement interval, I know I use way less 2T oil then when I premixed but I wouldn't make my decision based on that. Do you feel like it's not getting enough oil or is it that you don't trust the pump?
    Bitingdog likes this.
  5. thejrod

    thejrod Been here awhile

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    As a TPI, my bike ran really well, but I felt like the JD Tuner helped it run a little more crisp (leaned it out one click in the lower RPM zones). I switched to TBI mostly because I like to tinker, and am always looking for that extra 1%.

    What I noticed after doing the TBI mod:
    1. I needed a full turn more on the idle screw to get it to idle back up around 1600-1700. For some reason, as a TBI, it wouldn't idle at the same idle screw setting. I think having the idle turned this far up, the ECU thinks I'm giving it throttle when I'm not, and it's putting it into a richer portion of the map. It's slightly blubbery down low, and for the first time in 125 hours, I have a dribble of spooge out the tailpipe (also could be my FMF is finally filling up and needs a repack). I do have the issue others have reported where, after chopping the throttle, the idle drops down lower than normal - almost like the bike is about to stall. Mine doesn't stall though, so this hasn't really bothered me.
    2. The bike does seem to rev a bit faster. BUT I'm not sure this is a good thing, at least for my kind of riding. I ride harder-enduro type stuff, very slick, slimy conditions. When the rear tire breaks loose, the revs seem to "run away" much faster, and it's actually harder to catch these situations with the clutch. Whereas before as a TPI I could quickly pull in the clutch, the revs wouldn't skyrocket nearly as bad, and I could feather the clutch back out to regain traction very quickly. This characteristic might be desirable to some, especially those who are used to a carburetor with a slight lean surge off-idle. It's fun on an open track, like when I'm in 3rd gear and I want to dab and dump the clutch to break the rear end loose on a corner exit. Another anecdote that might help explain it - As a TPI, I ran it exclusively in Map 1. Now as a TBI, I've started to only run it in Map 2. The TBI almost feels like what an "SX map" should feel like.
    Lastly, as a TBI it ran really well, maybe even slightly better than it did as a TPI, but the loss in tractability made the difference for me.

    For hard enduro, extreme conditions, anything super technical, I think TBI as a mod to a TPI bike might be a hindrance for some people. Others who ride more open, faster trails and want that extra snap will probably enjoy it. Maybe TSP or others will address this with their upcoming TBI-specific mapping.
    Whatever KTM is doing seems to be working for their extreme riders, so I suspect the future OEM system will have a different feel than a TPI-modded-to-be-a-TBI (perhaps combined w/ an electronic powervalve will allow for much greater range of rider-selectable tuning).
    SthrnRomr, Moose465 and Bitingdog like this.
  6. adv_sacrifice

    adv_sacrifice Been here awhile

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    Neither. Lol. didnt have any sign of lack of oil when i had it apart.

    I know people have had their pumps last a long time.

    Not opposed to keeping it, but i wouldnt mind not having it either. tinker to tinker

    at 60:1 (2.13oz/gal) a quart of dominator should be ~14.78 gallons of fuel

    i think i used the oil tank capacity (600ml) in 5* tanks of fuel so 10 gallons = 2oz/gal so a bottle should ~15.78 gallons of fuel

    *cant remember when the light turned on, anyone have input?
  7. RideFreak

    RideFreak Torque Junky

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    I'll be curious if you feel it's leaner after removing the pump, I have no idea if you'll even feel it but by adding oil back into the fuel you'll have reduced fuel in the air/fuel mixture by 2% all else being the same.
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  8. adv_sacrifice

    adv_sacrifice Been here awhile

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    I have the jd 6x tuner so i should be able to adjust some
    RideFreak likes this.
  9. Snake Oiler

    Snake Oiler If the world didn't suck, we would all fall off Supporter

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    A tuner? Do you think these 300i really needs one. And if so what would I expect to notice from it.
  10. thejrod

    thejrod Been here awhile

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    No, it doesn't need one, unless you're planning to do mods like the TBI conversion.

    The thing about the TPI is the injection system is pretty basic - it can adjust for elevation and air temp, but that's about it. Since no two bikes are perfectly identical, they can run slightly differently. A tuner can help with fine tuning, but most bikes don't need it.
    trikepilot likes this.
  11. Snake Oiler

    Snake Oiler If the world didn't suck, we would all fall off Supporter

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    Thanks. I'm not planning any engine mods at present. But I haven't even rode it yet. Still in pieces putting Dan's wiring and other stuff on. Plus I've been lazy. Lol. Actually I'm helping my father get ready for winter since he's going in tomorrow for back surgery.

    Trying to decide if I want to swap out the tanks from the start. I know I'll be needing to soon. Desert life extra fuel and lots of water.
  12. adv_sacrifice

    adv_sacrifice Been here awhile

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    I added it after the rk tek head and it made a noticeable improvement
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  13. adv_sacrifice

    adv_sacrifice Been here awhile

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    Also the oil pump is monitored. With premix only and pump unplugged the bike does die after about 35 seconds. Tried multiple times and even holding the throttle slightly.

    Attached Files:

  14. RideFreak

    RideFreak Torque Junky

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    Depending on the ride you'll be able to do a comfortable 100 miles on the 3 gallon, especially if you're somewhere with some decent altitude like here.

    BTW, regarding the silencer we talked about last week, I was able to get one of the Powerparts versions of the Turbinecore 2.1. The FMF ver is still backordered everywhere as far as I can tell. The only difference between it and the FMF version is it's black.
    alvincullumyork and Snake Oiler like this.
  15. RideFreak

    RideFreak Torque Junky

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    Interesting, I didn't run it that long when I did the same test, without premix I didn't want to push my luck.
    alvincullumyork likes this.
  16. Snake Oiler

    Snake Oiler If the world didn't suck, we would all fall off Supporter

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    So is this right. The motor shutdown when the oil tank level drops to near drained? If so what's the chance of this happening when the bike on a lean angle?
  17. adv_sacrifice

    adv_sacrifice Been here awhile

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    Yeah im surprised as well.
    None. I completely unplugged the pump. The ecu must monitor current usage of the pump to determine if it can run
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  18. RideFreak

    RideFreak Torque Junky

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    It just lights a light when it's low, no shutdown.
  19. RideFreak

    RideFreak Torque Junky

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    If it's monitoring current then a small resistor cross the connections in the pump connector will fool it.
    alvincullumyork likes this.
  20. adv_sacrifice

    adv_sacrifice Been here awhile

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    Just got one with mating plug and frame plug from TwoRide (mexmex on the other forum).

    As long as the bike runs as clean as it did with tpi and doesnt foul plugs (partly worried since it will be using more oil constantly) this next ride then ill pull the oil system off.
    Snake Oiler likes this.