950 carb to efi conversion??

Discussion in 'Dakar champion (950/990)' started by Axalta2556, Jul 14, 2019.

  1. Axalta2556

    Axalta2556 If your gonna be dumb.. you better be tough!!

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    Anybody converted their 950/990 from carbs to fuel injection?? How big of a pain in the a$$ is and what would it even cost do so??
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  2. Zuber

    Zuber Zoob Supporter

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    Friend did it. Said it was a PITA and he'd never do it again. Way easy to just buy an 08-09 and just swap your accessories over.
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  3. Axalta2556

    Axalta2556 If your gonna be dumb.. you better be tough!!

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    Yea I’d imagine it would be a pretty major undertaking!
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  4. ElJorgio

    ElJorgio Been here awhile Supporter

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    I swapped my 2006 990s fuel injection for carbs from a 2003 950. It's only a pain in the ass if you are in a hurry to get it done, I was in no hurry and thought it was a fun and interesting project. I swapped wiring harnesses.
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  5. bdking

    bdking Adventurer

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    It’s really not that hard. It took a few trips to eBay & the dealer as I realized which sensors I needed, and I ended up just buying a 990 left tank & fuel pump. I did already have a 990 timing ring around so I’m not sure if those are hard to find. I expect it’s still a dealer part or you could pick one up from someone doing an fcr conversion.
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  6. Zak Smith

    Zak Smith *

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    I own an 06 950 "S" model and a 13 990. The 950 is smoother and "feels like" it has more torque in the mid range.
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  7. Zuber

    Zuber Zoob Supporter

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    This is not the usual case, I think it's just that the 950 is jetted correctly and the 990 is not.
    By 'smooth' I assume you mean vibrations? The 950 with carbs has better throttle response from the factory.
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  8. Zak Smith

    Zak Smith *

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    No, that's not what I mean.

    The throttle response is smoother. This is a common comment about the 990 vs 950, as well as a general theme of mature carb'd bikes vs. usually "First Generation" EFI bikes (often described as jerky throttle response; the same exact feedback applied to the Gen4 vs. Gen5 VFR in the 90's). There are threads on here going back to 2006 that talk about the same issue. https://www.google.com/search?clien...dvrider.com+ktm+990+jerky+throttle+950+smooth

    Both bikes are jetted right. The 950 is tuned very well, and the 990 has a full Rottweiler system with closed-loop PCV to optimize for correct AFR.

    This is not a comment knocking EFI in general or to indicate that I have a problem with EFI. My 500 XCW, Ducati, and 1290 SAR all have fuel injection and throttle response that is very smooth. The 500 is dead spot on.

    In the 990 vs 950 case, one net result is that the 950 is easier to ride off road. But you do have the hassle of a carb.
    #8
  9. Wheelie junkie

    Wheelie junkie n00b

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    I thought about doing this as well, rear carburetor is upside down and runs out of fuel on extended long wheelies, a big drag! Floats bounce too much in woops causing loading up also.
    #9
  10. Whodatschrome

    Whodatschrome Long timer

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    So I'm guessing that for the conversion some of the other parts needed would a 990 wire harness (and any corresponding sub-harnesses), computer, all the sensors, speedometer, timing ring, left side tank, throttle bodies, and other little things. If the 990 that you got all the parts from had ABS, will that complicate the conversion (if you don't want ABS)?
    #10
  11. bdking

    bdking Adventurer

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    Yes, a wiring harness and an ECU. My eBay wiring harness had most of the sensors still attached to it. The speedometer is the same so no need to change that. You'll need a left side tank & fuel pump unless you rig up another inline fuel pump (I didn't mess with that but I've seen write-ups from people who have for 950 SEs). The wiring harness has a plug for ABS but if you just don't install any of the ABS parts you shouldn't have any problem, and if you keep your 950 speedo you won't have the ABS switch or warning light anyway.

    I believe the water temp sensor is the same and I know the oil pressure sensor is the same, you basically need the air pressure sensors. Make sure the ECU you buy is pre-immobilizer. I just wired in resistors to blank off the kickstand sensor and tip-over sensor. You obviously need a throttle cable too.

    I used the throttle body from an RC8 1190, which I believe has slightly larger injectors and fits just fine. I started out with a Rottweiler intake but Nels at 2wheeldynoworks encouraged me to ditch it for a Motohooligans. Nels says he's seen LC8s damaged by dust getting past the Rottweiler. That said Jimmy Lewis runs the hell out of his bikes in the desert with Rottweilers so I bet they're fine.

    That's all off the top of my head, but if anyone has specific questions I can go through my notes. I printed a huge copy of the wiring diagram and put notes all over it to try to help future-me with service issues. The bike I did this to was really far from stock before I had it, it had a 990 SMT motor converted for FCRs and the AWD hardware changed where I had to run the harness and mount sensors. I'm sure it would be more straightforward on a stock 950.

    I have a 950 as well as a couple of 990s, after dyno tuning the 990s are every bit as smooth fueling as the 950.
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  12. Whodatschrome

    Whodatschrome Long timer

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    Oh, THAT 950! I actually meet Gregor a couple months ago at the "Back 40 Enduro". Neither of us were on big bikes at the time, but after the ride was over with we somehow got to talking about the 9x0 Adventure bikes...and low and behold it turned out he had a 2wd 950 at one point! Of course i knew about the bike build thread, and have seen it around town a few times, (most recently at SEE SEE last summer). But i never knew the guy(s) who were behind it. It sounds like Gergor knows pretty much all of the famous people (now including me).

    The reason i have interest in going FI is because of the bogging that the whoops cause to my CV carbs (mine's a blue 2006 950A S model). I just lowered my floats from just under 3mm to about a 4.1mm. If that doesn't clean up most of the bogging, i will most likely plan to convert over to FI. I'll most likely keep my existing 950 engine (30k miles) because it runs excellent. I would like to keep a stock airbox because they work very well for me. Yes they take up lots of space, but they do a terrific job of keeping the air filer clean. As much as it would be kinda cool to have a late model 990 display, i think just keeping my 950 display would be a better plan...plus the odometer mileage would be accurate to the bike. I'm not after squeezing more horsepower out of my engine. Since my bike sees a true 40% dirt/ 60% pavement, i have really no need for more HP in the dirt. And i just see the tarmac as an inconvenience to get to the next trailhead. I've never had anything dyno tuned, so i'm guessing that it means that the bike needs to go on a dyno to get tuned? So how long does that take? Is it super expensive? Is there a local shop that you recommend for that?

    I think the most difficult part of the project for me is to find a left side 990A tank that is blue colored to match my blue bike.
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  13. bdking

    bdking Adventurer

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    2wheeldynoworks is in Seattle but they have a trailer they bring down to Vancouver, WA from time to time. I forget what exactly it costs, but the benefit I see isn’t horsepower. It’s smooth throttle response and accessible torque down low. Email them if you end up switching to see when they’ll be around, it is especially worthwhile off-road.

    if you keep the 950 motor you’ll need a 990 tone ring. I’m not sure if those are still available from KTM or not.

    if you want to keep the blue tank just chase down a different, in-line fuel pump. You might be able to splice in the mounting plate for a 990 pump into the bottom of your tank but that seems nutty / risky.
    #13
  14. Whodatschrome

    Whodatschrome Long timer

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    Thank you for that info. And yes, I’d be after a smooth throttle response and down low torque. And I’d look at the tuning as an investment, rather than just more money spent.

    Are different sized injectors needed if I decide to use the 950 engine, or does the dyno tune take care of that? And is there any other benefit of swapping in a 990 other than a little more HP (that probably wouldn’t be able to be utilized anyhow in the loose dirt and rocks)?

    And no way would I ever entertain doing an external fuel pump for anything that has fuel injection. That kinda of thing I consider hack.
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  15. opanos

    opanos Been here awhile

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    I am not really sure if it is a good idea to turn it in an FI system, too much hussle for no actual gain. If it is only about the bogging, probably proper jetting and correct float height will do the thing for you. Try setting the f.height back to 3mm (you actually made it prone to bogging by setting the height to 4mm)
    plugging the acv circuit and adjusting the pilot air circuit would also be beneficial
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  16. ElwoodBlues

    ElwoodBlues Been here awhile

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    Or get another set of carbs, clean them and see if it feels different.
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  17. Whodatschrome

    Whodatschrome Long timer

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    I’m pretty sure that my existing carbs are fine. It’s just when I hit a series of about 5 hard whoops in row, the bike will load up with fuel and then sputter to a stop. Any other type of terrain they are spot on. The bogging is a know issue with CV carbs. I also heard from my friend that even the FCR carbs didn’t fully cure that issue for him.
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  18. Whodatschrome

    Whodatschrome Long timer

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    I was understanding that lowering the floats 1mm from the factory spec (3mm to a 4mm) would lower the fuel level in the carb? I think my issue is that the bike foods out in the whoops. I don’t think it’s being starved for fuel.

    I’ve heard about plugging the ACV circuit, but I don’t know anything about that mod. Do you have more info (or a link) about it?

    *and no, it’s not the fuel pump. I have a brand new KTM pump that has been Dr. Beaned.
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  19. GezwindeSpoed

    GezwindeSpoed Long timer

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    I also lowered the floats from 3 to 4mm and it did help a bit. What was more interesting, my aftermarket fuel pump (for old timer cars) gave a too high fuel pressure. I went back to OEM pump (with Dr Beans) and the flooding was totally gone. Do you use the standard pump?
    #19
  20. Whodatschrome

    Whodatschrome Long timer

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    Yes. I have always used the standard OEM pump. I even bought a brand new one last season to replace my old one that quit working (the points were burned up). I then promptly removed the (new) points from the new pump, and installed them on my old pump (to be used as a spare). My new pump was then upgraded with a Dr. Beans kit. I read too much about pressure inconsistentencies when using all of the aftermarket approaches to "fixing" fueling issues on the 950 bikes. I don't think there is a more reliable (or simple to install) pump for our bikes than an OEM with a Dr. Beans upgrade. My floats are now at about 4.1mm. I just need to button the bike back up (i need to finish up some other cool modifications first though), and find some whoops that are somewhat close to where i live. The bike runs great if i only hit about 3 big whoops, but if there's around more than 5, the bike will sputter to a stop.
    #20