KTM LC8 Air Filter Kits by SW7

Discussion in 'Vendors' started by Sporting Wood, Mar 14, 2013.

  1. Thumper996

    Thumper996 Been here awhile

    Joined:
    Jun 23, 2009
    Oddometer:
    593
    From the strip of oil on the base I would say my filter is sealing nicely.

    [​IMG]

    [​IMG]
  2. RENCRN8

    RENCRN8 Been here awhile

    Joined:
    Aug 14, 2007
    Oddometer:
    255
    Location:
    Loveland, OH
    So after reading about greasing the edge(which I didn't), I was wondering if that could be contributing to my somewhat lean condition.

    2006 950
    FMF cans
    175 main F/R
    45 pilot F/R
    Stock needles in 3rd groove
    Float height 4mm F/R
    Flex jet screws 4 turns out F/R

    Runs pretty good but still a little leaner than I would prefer based on riding characteristics and confirmed with multiple plug chops at varying RPM's.

    Any ideas?
  3. Sporting Wood

    Sporting Wood I

    Joined:
    Oct 18, 2011
    Oddometer:
    897
    Location:
    Horneytown, NC

    You aren't going to be sucking much if anything through the sealing gasket, even dry.

    In my experience, your settings are a slight bit rich for the typical bike. Are you getting any backfiring? Stock air jets, right?
  4. RENCRN8

    RENCRN8 Been here awhile

    Joined:
    Aug 14, 2007
    Oddometer:
    255
    Location:
    Loveland, OH
    No backfiring. Slight surging and whiter plugs than I would like.
  5. Thumper996

    Thumper996 Been here awhile

    Joined:
    Jun 23, 2009
    Oddometer:
    593
    As far as the surging goes, I would start with raising the needles, I am at notch 5, but I have 70 air jets (instead of stock 50 and I may try a 60 down the road) Mine surged like a pig on notch 4, notch 5 fixed 99% of the surging. Only has a barley noticeable surge in the first 15 minutes or less of engine warm up riding.

    I am running Factory Pro Ti needles and not stock, so keep that in mind.

    Can't comment on the mains you have, but they do seem a bit large. I am way under that and my full throttle roll-on is excellent.

    Good luck!
  6. Sporting Wood

    Sporting Wood I

    Joined:
    Oct 18, 2011
    Oddometer:
    897
    Location:
    Horneytown, NC

    Sounds like you know what you're doing. Could be float height. They can be a major PIA to get right. I've set them and came back later and found they had 'moved.'

    I would check float height and re-adjust if necessary.
    I'd pull the air jets and make sure they're stock...many bikes have been leaned with fat air jets.
    I'd double check the vacuum ports on the intakes and possibly the slide diaphragms, make sure something isn't leaking.

    All that checks out, I would either enrichen with a higher float or raise the needle.
  7. Sporting Wood

    Sporting Wood I

    Joined:
    Oct 18, 2011
    Oddometer:
    897
    Location:
    Horneytown, NC
    No grease but lots of UNI oil works pretty good to seal the flange imho. I'd still recommend a thin streak of some goo along the gasket though. Great PICS!
  8. keener

    keener Speed changes you.

    Joined:
    Feb 24, 2010
    Oddometer:
    1,040
    Location:
    Toronto, Canada
    I got the filter in...lots of power everywhere.

    I have two issues. Idle is unstable and I see a big surge form 3000 to 6000 when in nutural. But that is not noticeable much when riding.

    Idle is impossible to set. I was riding just now and had to stop several times to turn the idle down or up. I have flexjets installed so I played with them too, no dice.

    I set the idle to about 1400 and rev the engine a couple of times then let go of the throttle, rpm comes down to 2200 then about 10 second later it may slowlly come down to 1400 or lower and it goes up and down, its unstable. Also I think bike is running a bit hot but I may be wrong because its about 30c out there here.

    Here is my setup:

    170/172 mains
    45 air jets
    70 idle air jets
    4mm floats level
    Factors pro Ti needle on 3 clip.
    I tried 1 to 3 turns on idle mix screws

    SAS removed, FMF pipes.
    I checked TPS yesterday it was set correctly.

    Fuel consumption is not bad at 6.3ltr/100km or 37.3mpg

    Any ideas about the idle issue?
  9. speedmonkey7

    speedmonkey7 Been here awhile

    Joined:
    Jan 26, 2011
    Oddometer:
    337
    Location:
    Thousand Oaks, CA
    Hi, this sounds to me like you are not getting a good seal on the engine side of the carb in the intake boots. Did you get the carbs firmly seated in the intake boots? I know I've thought they were and then, luckily, checked before I put it all back together to find a small gap. That would be the only thing that I can think of that would cause an un-stable idle and everything you are describing. I'd start there.

    Also, my old XRR had a very finely cracked intake boot that was leaking the tiniest bit, and I had ALL of those exact issues. I did about $300 worth of other crap, and spent months of chasing my tail, because I just didn't think the boot was bad. It could be that too. Pretty easy, and cheap thing to check first. Good luck!

    I'm very interested in these filter systems, just using the rest of you as guinea pigs, I'm a bad person I know... :shame :freaky
  10. keener

    keener Speed changes you.

    Joined:
    Feb 24, 2010
    Oddometer:
    1,040
    Location:
    Toronto, Canada
    Yes. It is heat shield on the buttom of the plate. I also made this[​IMG]
  11. keener

    keener Speed changes you.

    Joined:
    Feb 24, 2010
    Oddometer:
    1,040
    Location:
    Toronto, Canada
    Thank you, now that I think about it I can not remember tightening the clamps on the button of the carbs!

    I meticulously checked the diaphragms they are fine.
  12. Sporting Wood

    Sporting Wood I

    Joined:
    Oct 18, 2011
    Oddometer:
    897
    Location:
    Horneytown, NC
    Hey, you might want to spin that thing around. Its on backwards. Could be your seat is pressing down crushing the filter or even cantilevering the front carb out of the intake boot.
  13. speedmonkey7

    speedmonkey7 Been here awhile

    Joined:
    Jan 26, 2011
    Oddometer:
    337
    Location:
    Thousand Oaks, CA
    Yeah that would certainly cause the air leak! At least that's a cheap and easy fix to your issues!

    Sent from my SAMSUNG-SGH-I547 using Tapatalk 2
  14. Thumper996

    Thumper996 Been here awhile

    Joined:
    Jun 23, 2009
    Oddometer:
    593
    Thanks but no thanks on grease. I am asphalt only so little to know dirt or dust like Adv riders will get. Now on mg CRF I do grease.
  15. DirtJack

    DirtJack Adventurer

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    Aug 12, 2007
    Oddometer:
    1,609
    Location:
    San Antonio, Texas
    Sporting Wood, I sent a PM last week. :D
  16. mousitsas

    mousitsas Long timer

    Joined:
    Oct 10, 2008
    Oddometer:
    3,006
    Location:
    Athens, Greece
    Fellow SW ITG'ers, does float height affect choice of main jets?
  17. speedmonkey7

    speedmonkey7 Been here awhile

    Joined:
    Jan 26, 2011
    Oddometer:
    337
    Location:
    Thousand Oaks, CA
    From what I understand, yes. Float height seems to be a huge deal on our CV carbs. It seems to me that you should set the height at stock and jet around that though. I read an article by a race team that uses float height to to tune a bit, but I didn't understand much else it said,lol. For mere mortals just stick right at or around stock height.

    Sent from my SAMSUNG-SGH-I547 using Tapatalk 2
  18. CBRacerX

    CBRacerX Adventurer

    Joined:
    Apr 14, 2013
    Oddometer:
    23
    So I've put some miles on this setup (Filter and Factory Pro Jetting Kit from SportingWood of course) with my 2006 950 SM



    • 170F/172R mains
    • Factory Pro #2 needles in the 3rd clip - both OEM washers in place (thin on the pointy end, thick on the dull end)
    • 45 slows
    • Floats at 4mm
    • Idle Mixture Screws at 1.25 turns out
    • Carb Air lines with single filter and y-connector is installed and the airline is pointing down (stock lines)
    • Akro Cans (old style) with Restricters In for Street, Out for Track

    Issues:

    Backfire: A fair amount of mild backfire is present when jumping off throttle at and above 4K, which I would like to eliminate.

    Surge: Did some extended highway cruising and found a steady surge when at 1/4-1/3 throttle (75-80 MPH steady cruise on flats) where the bike will not slow down enough to change the speedo reading but I can feel a back and forth cycling in the power delivery.

    Hesitation: Went to the track this Monday (NJMP Thunderbolt) and found that when accelerating on the front straight, shifting at 8K RPM and WOT in the next gear produced a hesitation before power was delivered. If these carbs had an accelerator pump, I would diagnose that it was blocked. This is the biggest issue I would like to solve.

    Any suggestions from those that have gone before on the next steps?
  19. Sporting Wood

    Sporting Wood I

    Joined:
    Oct 18, 2011
    Oddometer:
    897
    Location:
    Horneytown, NC
    4000 rpm is where the needle takes over and begins to open. I would open up the screws a quarter turn first and gauge if this is enrichening the low end too much at the expense of correcting the pilot circuits top end (4000rpm). Then I'd consider raising the needle a clip. Seems every bike likes a different clip position.
  20. vwboomer

    vwboomer Buffoon

    Joined:
    Feb 12, 2008
    Oddometer:
    11,289
    Location:
    WI
    I thought I might report back after my trip to Colorado with this setup. Before leaving, here at about 900ft ASL I was running 45 pilots and 175 mains. It ran great, no popping, plenty of power. I dropped to 42 pilots for the trip and immediately noticed a loss of power at home.

    Jumping from less than 1000 ft to 14000 feet naturally causes some issues. The bike did ok on the road but was pretty handicapped above 9000ft. On the trail, it was rich enough to be a liability. Trying to climb up loose rocky bouldery passes was a problem. On one switchback going up hill, the bike basically fell on it's face and I dropped it breaking off most of a footpeg. I think that was about 12500 feet.

    It's hard to know how to jet around altitude when you are covering such a huge range. Fuel injection is definitely the way to go :thumb

    If I were heading that way again, I might run 170 or 172 jets to try to bridge the gap a little.

    Mileage varied between 20mpg and 43. I think the sweet spot was about 6000 ft. boiling fuel out of the vents was a big factor at anything above 4000 ft on tighter stuff, and at any riding above about 9000 ft.

    It was nice to return home, clean the prefilter/filter and change the pilots back in under two hours :thumb