FactoryPro Jet Kit...cure for what ails your carbs!

Discussion in 'Dakar champion (950/990)' started by Gixxer2go, May 16, 2005.

  1. MookieBlaylock

    MookieBlaylock Long timer

    Joined:
    Feb 29, 2004
    Oddometer:
    2,584
    Location:
    IntheeaglewingpalaceoftheQueenChinee
    exactly---that is why the jd kits are so awesome. You get concise directions that allow for different altitudes,humidity and temperature. You can jet your bike at sea level for a trip up to the mountains and arrive and just ride with a perfectly running machine. George if i was trying to set up my 950 with the fp kit i would totally appreciate your help
  2. randel

    randel Been here awhile

    Joined:
    Jan 25, 2006
    Oddometer:
    429
    Location:
    Tallinn, Estonia
    Many thanks for all for comments and suggestions.
    I replaced sommer doors with original covers, IMS now 0.9 and FP needle in 3rd clip. I also tried original needle @ 3rd clip, but FP needle gave more "snap" at mid rpm so I switched back to FP.
    Overall experience - more backfiring when decelerating (probably a bit lean IMS?), a little bit less snap mid rpm, not so easy to lift front wheel (was worse with original needle). But old problems are disappeared now (hesitation when accelerating).
    Can not comment about fuel consumption yet.
  3. Pete640

    Pete640 Long timer

    Joined:
    Nov 23, 2008
    Oddometer:
    2,127
    Location:
    Earth
    Simple fact is that whilst parts of the kit are extremely well made they cannot be used effectively together - which should be the case. A combination of the OEM and FP parts produces the best results.
    As for the jets - Ive just ordered more from Steve at Mick Hone in Melbourne (03 9897 1568) and their service was great. Couldn't be easier.
    Also - FYI - Ive just been speaking to Nick at Unifilter who said they will have a replacement air filter for the 950/990 in the next couple of months. He is aware of the airbox issues and this has caused their r+d major problems re jetting/metering but he says they have overcome the issues and the filter will not affect them - being serviceable as well. Cool.:clap

    Pete :1drink
  4. renogeorge

    renogeorge Let's ride!!

    Joined:
    Apr 7, 2007
    Oddometer:
    6,525
    Location:
    Reno
    My SM and 2 SE's I have set up work very well using only the FP parts. I have not tried a pre filter or the other kits so I have no comment on those.
  5. mynameis

    mynameis Been here awhile

    Joined:
    May 22, 2006
    Oddometer:
    239
    Location:
    Somerset.United Kingdom.
    Very interesting thread,loads of info from everybody.Only slightly off topic regarding the FP kit,around pages23ish onwards there was a piece about drilling the slides.Does drilling the slides richen the low end mixture or just allow the slides to open quicker?Also do you drill both slides?Curious to know,drilled the slide on my 640 but thats only one slide to replace if it goes wrong and not two of them! lol
  6. mookymoo

    mookymoo Mookish Mook

    Joined:
    Aug 26, 2007
    Oddometer:
    4,430
    Location:
    Either UK or Australia ...
    Its so the slides operate quicker.
  7. mynameis

    mynameis Been here awhile

    Joined:
    May 22, 2006
    Oddometer:
    239
    Location:
    Somerset.United Kingdom.
    Thanks for the reply.It doesnt alter the mixture enough to make a difference?
  8. mookymoo

    mookymoo Mookish Mook

    Joined:
    Aug 26, 2007
    Oddometer:
    4,430
    Location:
    Either UK or Australia ...
    Its nowt to do with mixture as such (not directly, anyway).

    The slides have a spring in them that keeps them closed - they have a bellow on the other end which the vacuum acts upon to open them.
    Air moving through the hole(s) in the slides as they move is what provides the damping. The air damping means they open/close at a controlled rate.
    Decreasing the hole size would make the slides move slower (more damping). Increasing the hole size would make them open quicker.

    If they opened too fast, however, it would be like an FCR carb without an AC pump - ie mixture would temporarily go very lean as the wide-open slide would allow lots of air, but the venturi would not have caught up yet to match it with the correct fuel quantity.

    (someone correct me if I am talking out my ass here - my knowledge in this area is not very strong - and Im sure a couple of details/terminology are wrong)
  9. mynameis

    mynameis Been here awhile

    Joined:
    May 22, 2006
    Oddometer:
    239
    Location:
    Somerset.United Kingdom.
    I`ll give it a test ride tomorrow,ran out of time now.Just out of interest the holes in my slides were 2.5mm so i took them out to 3mm like some in the thread.cheers
  10. Head2Wind

    Head2Wind MotorcycleMayhem

    Joined:
    Mar 13, 2006
    Oddometer:
    2,711
    Location:
    NorthWet Washington
    mooky is right on target regarding the hole.

    if you go too big with the hole you do not have to replace the whole assembly, you can solve it by drilling/taping the hole and threading a headless nylon screw into the hole and then redrilling the screw to the corrected size. the nylon does not present significant mass and is easy to work.
  11. mynameis

    mynameis Been here awhile

    Joined:
    May 22, 2006
    Oddometer:
    239
    Location:
    Somerset.United Kingdom.
  12. jaydee1445

    jaydee1445 Footpeg Crash Tester

    Joined:
    Jul 20, 2006
    Oddometer:
    4,886
    Location:
    high sided into the orange grove
    Had the opportunity to ride Scribe's 04 9fiddy with a headwind kit. Confirmed what I expected, :bore much softer than my FP set up @ every RPM and really lacking the midrange hit. :snore Restrict the intake and go with way small jets, I don't get it.:dunno
    Guess it's OK if you can't follow instructions or don't want to take your carbs off 15 times. :lol3
    Scribe kept saying my set up had more punch but He gets better mileage. :lol2
  13. KTMSER

    KTMSER Big bike friendly

    Joined:
    Nov 7, 2006
    Oddometer:
    2,779
    Location:
    Six feet from hell Phoenix AZ

    Never understood this either.. Might as well add a restricter plate...:lol3

    Not knocking HTW's kit he set it up to offset the restriction created by adding a prefilter...

    There is a happy medium if you take the time to find it..
  14. mookymoo

    mookymoo Mookish Mook

    Joined:
    Aug 26, 2007
    Oddometer:
    4,430
    Location:
    Either UK or Australia ...
    The added vacuum from the pre-filter speeds up the carbs.

    I found the response generally improved - but it had a tendancy to bog a bit if cracked wide open from 3krpm
    And the dyno tests dont support the theory that its down on power...

    That said, I think the std H2W mains are perhaps on the rich side.
    And more importantly, it doesnt take a lot for that pre-filter to start clogging & affecting mixture/response.
  15. jaydee1445

    jaydee1445 Footpeg Crash Tester

    Joined:
    Jul 20, 2006
    Oddometer:
    4,886
    Location:
    high sided into the orange grove
    Improved over what stock or a sorted FP kit?

    The cracked WFO at 3k is where I feel the biggest improvement, but that is where I spent the most time tuning.

    Not knocking the H2W just my $.02
  16. mookymoo

    mookymoo Mookish Mook

    Joined:
    Aug 26, 2007
    Oddometer:
    4,430
    Location:
    Either UK or Australia ...
    Stock.

    It seemed to me (reading this thread) that after a bunch of inmates spent considerable time trying, the FP got slated as being overly rich. :dunno
  17. jaydee1445

    jaydee1445 Footpeg Crash Tester

    Joined:
    Jul 20, 2006
    Oddometer:
    4,886
    Location:
    high sided into the orange grove
    FP starting points are way rich. Most Adventure riders won't pull the carbs 15 times to find the right combo.
    Every one wants to have a magic bullet that drops in.:wink:

    I gleaned the best starting point from the jetting matrix thread and a long conversation with Marc @ FP. I changed the jets then went back in to increase the float height to fix the 3k bogg. I sure I could get it better if I followed the steps in the instructions. If you do call FP be sure not to whine about how much work it is too pull the carbs.:lol3
  18. mookymoo

    mookymoo Mookish Mook

    Joined:
    Aug 26, 2007
    Oddometer:
    4,430
    Location:
    Either UK or Australia ...
    If you read the start of this thread, Id guess the guys doing the work pulled carbs way more than 15 times...
    Worthwhile reading up - maybe you can spot where they went off-track
  19. renogeorge

    renogeorge Let's ride!!

    Joined:
    Apr 7, 2007
    Oddometer:
    6,525
    Location:
    Reno
    I have not tried the H2W "kit" so I have no first hand knowledge. But in general terms, restricting air flow with more restrictive air filter (such as the pre filter in series with the stock filter) is no different than putting on a smaller carburetor. This could be good if you want more low end power and are willing to sacrifice some top end. For primarily dirt ridden LC8s, I can see how this might be desireable if you want your KTM to have power more like an enduro or trials bike.

    I have never understood the assertion that reduding air flow with a pre filter will somehow help the diaphram controlled slides in the stock CV carbs operate quicker or more responsively. Reducing air flow through the carb reduces vacuum created to overcome the springs and lift the slides. So without something else changing (slide vacuum holes enlarged or weaker springs installed) I am not seeing how the pre filter helps in this regard. If you need extra filtration, that is something else. Just lean out to match for the reduced air flow and off you go.

    The whole deal with these "kits" bothers me too. Don't get me wrong, I have used a variety of kits for my street and dirt bikes. And I have put my own jetting together a piece at a time. I have to think that for most riders the kits are still the way to go. But you still need to work through the normal steps of jetting (main first, float level set, etc.). Even with these kits (and I am going to say all of them) you still have to put in the time and think through the process. I have yet to hear of a kit that is consistently perfect out of the box or bag or whatever the hell they come in.

    So, study the wealth of information that is out there on jetting. It is really NOT that complicted. Prepare to spend time with trial and error. And be methodical in your testing and recording of what changes you have made and what results you obtained. It is really fun and satisfying IF you are into this sort of thing. Otherwise get something fuel injected, add a power commander and plug in your lap top.....
  20. jaydee1445

    jaydee1445 Footpeg Crash Tester

    Joined:
    Jul 20, 2006
    Oddometer:
    4,886
    Location:
    high sided into the orange grove
    I was editing above when you posted.
    If you can find the jetting matrix thread it is a wealth of info.