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My Madass 160 Build

Discussion in 'Modifications and Projects' at netrider.net.au started by Sage, Feb 3, 2011.

  1. #1 Sage, Feb 3, 2011
    Last edited by a moderator: Jul 13, 2015
    I know a lot of people were interested in the Madass Mods post so i thought id share my project..

    I finally took my madass for its first ride last night! Did about 4k's just to start to run in the engine and to shake anything loose before i go over it again. Took it up to about 90kmh and it was doing it easily.. didnt really go over about half throttle though it had plenty of go!

    Its a 2006 Madass 50cc with custom handle bars and rear view mirrors.

    Running a Pitster Pro z160HO Engine

    30mm Mikuni Carbie.

    This light weight stator to provide plenty of electrical grunt and to help it rev nice and quickly

    37T rear sprocket (as small as they get only a couple of mm smaller and the chain would be rubbing.

    Aftermarket rear shock
    video of rear shock in action here: [media=youtube]nE6Z5lK0SGk[/media]

    Only other mods is i have removed the 2nd half of a factory 125 exhaust and i am currently running it muffler free.. its VERY loud and sounds awesome! to be perfectly honest i love it! though i really need to quieten it down by about 10-15% otherwise ill be cop bait..

    Have also removed the rear guard assembly put on a neptune rear carrier bracket and reseated all the wiring and numberplate housing..

    Still need to work out what i am going to do with the exhaust and need to mount the oil cooler and work on lowering the seat tho other than that good to go!

  2. good work, i used to ride the 125 version.
  3. All that work and still no petrol tank! ;)

    Best colour for a m/cycle is silver.

    cheers Michael
  4. I've got an almost new 250cc thumper engine I'll let you have cheap....

    nothing exceeds like excess...:angel::angel::angel:
  5. Keep us updated, cool build.
  6. Thanks for the replies guys :)

    Took the madass out again last night.. still cant get the fukn thing to idle unless the choke is on! really odd cause the idle adjustment only effects the idle when the choke is on! as soon as i turn it off the thing conks out! Could be jetted incorrectly..

    Anyways.. 1st is good for 40kmh.. 2nd to about 65.. 3rd is good for about 90.. so looks like it will top out about 120 which is more than i need.. I might have to change the front sprocket..

    Nice usable power.. tho the gears might be a tad too long if you ask me.. as i tend to sit in 3rd at about 70 rather than 4th and as a commuter 70 is the sweet spot.

    Still havent used wide open throttle.. and it would be nice to have a RPM gauge i am guessing i am only reving to approx 6000..

    Anyways the running in continues only done about 20k's. Will drop the oil and replace the filter in another 10 or so.
  7. Conks out when you turn the choke off....splutters to a stop or just stops dead??? Is the sparkplug wet or dry ??

    check the seal between carb and ceramic heat shield and inlet manifold and head, any air leaks would cause a lean idle.
  8. splutters to a stop.. havent checked spark yet.. will take a peak at the seal on the weekend thanks for the advise :)
  9. seal appears to be ok.. something odd going on.. think it must be the wrong jet.

    anyways still goes well on half choke! here is a better pic too!

  10. splutters to a stop suggests 'rich'. A wet sparkplug would confirm that.

    Mikuni carbs of this type have idle jet, air bleed screw and idle stop screw. Basic ball park for the airbleed screw is 1 3/4 - 2 turns out from fully in
    Screwing the airbleed in makes the idle richer, screwing it out makes the idle leaner. That said if it requires more than 1/2 a turn or so in either direction then a change of idle jet may be required.
    Ensure also that the needle ( centre of the slide ) is set with the circlip in the middle or 1 either side of middle groove. The circlip going in grooves toward the tip of the needle will make things richer.
  11. Hi Sage
    I'm in the process of building a MA myself. If you want to really wake up the 160 try an OKO carb. The 28mm is the best for performance, but they can be a little temperamental to tune. The 26mm is great and easier to tune. The Chinese copy mikuni’s are renowned for being dodgy.
    OKO's available from DHZ (I have no affiliation with DHZ just a happy customer who has been buying there for years)
  12. thanks for the info Saber. I am aware that OKO are very good and a bit hard to tune :) Though i think you a bit misinformed. Mikuni are Japanese and are not a clone of any other technology. I believe your thinking of the Molkt Carb which is a Mikuni copy.

    Btw i finally did get it to idle properly. Issue with the choke on the carb. Linkage fixed and now all ok!
  13. Hi Sage
    The 26mm OKO is easy to tune it's the 28mm that can be finicky on these horizontal motors. Many of the mikunis that are sold are Chinese copies most are actually considered to be 22mm although many are sold as anything up to 30mm, this is because of the oval bore that the copy ones use so some people measure them either at the venturi or the height of the oval when infact the correct way to measure them is the width of the throat where the slide is. If your carb has a oval bore it is 99% to be a Chinese carb. I have never seen a genuine mikuni with an oval bore (I have been building and racing with these motors for years).
    here is what a Chinese copy looks like.
    real one with round bore
    Glad to hear that you got yours sorted.
  14. very good info there! will take mine apart in the near future and have a look :)

    im hoping its a legit one as it was sold to me as that. If it is a legitimate 30mm mikuni is it worth going to a 26 or 28 OKO? what sort of gains would i get?

    Keep in mind that this MA is a commuter so i want something provides good power across the entire rev range.

    if you have a lot of experience with these engines i should ask is the oil cooler even required for a commuter? Granted melbourne does get damn hot in summer though i try to avoid riding it when its over 32c.

    i guess ill set it up anyway its cheap insurance and lets it hold more oil..

    i have been riding so far with out it.. though its only been 21c on less outside.
  15. just did a search to help me find out a bit more about the copies and i came across this:

    so now im not sure whats going on :)
  16. Hi Sage
    I would use an oil cooler on these motors in any circumstance, it will reduce the oil temp and temp kills oil, dead oil kills motors. In a commuting scenario it is possible that you would be standing still a bit and that’s when a cooler will help.
    For a carb I would stick with a 26mm for commuting as this will give the broadest spread of power. I have been told by other people that build these motors for racing that the round slide carbs are a little less aggressive than the D slides, I usually use a D slide because I like the aggressive power delivery.
    An upgrade to the D slide OKO would produce a very noticable boost in power and torque. I can only coment on the D slide as that is the carb I have the most experence with. I do know that others prefer the smother power delivery for racing but I dont.
    In my opinion these would be the carb to choose from
    Genuine jap round slide
    or the OKO

    If you want to see my madass build it is logged here
  17. #17 sabertooth_buterfly, Feb 18, 2011
    Last edited by a moderator: Jul 13, 2015
  18. wow that looks pretty mean! you can barely recognise it :)
  19. saber, that is AWESOME
    I want to get another madass just so I can get that done !!
    Is it roadworthy??