212 predator build

Discussion in 'High Performance Bicycle Engine Tips and Motorized' started by Amarion1, Nov 28, 2015.

  1. Bow

    Bow New Member

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    Amarion1,

    Nice build.

    May I ask where you found this curved Intake Manifold for the Carb?

    [​IMG]

    I have been looking for one of those...
     
  2. Amarion1

    Amarion1 New Member

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    Thank you!

    I got it with my carb at tboltusa.com. it doesn't fit right with out some modding though. But it could easily be cut in half and used with a tube and hose clamps if you don't have the patients to make adapters like I made

    http://tboltusa.com/store/mikuni-22mm-carb-kit-br-fits-pit-bikes-and-other-minis-p-107.html
     
  3. Amarion1

    Amarion1 New Member

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    Here's a couple pictures. Still a bunch to do yet but she's coming along. Still need to cut out the in frame fuel tank and build the rear brake mount for the jackshaft. A couple odds and ends and she's golden!

    [​IMG]
    [​IMG]
     
  4. MotoMagz

    MotoMagz New Member

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    Looks really good! Now finish it !dance1
     
  5. Amarion1

    Amarion1 New Member

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    Today I bought a 203mm front brake rotor and installed it. The 160 didnt seem safe enough.. Tightened the front wheel spokes. Bought and installed handle grips. Bought a front and rear light. And installed the wide crank kit and some pedals I found. The bicycle chain sprocket doesn't fit so there's no bike chain for now.

    Still needs the fuel tank. Bike chain. And rear brake. I'm having a rear brake disc cut out on the laser at work when the operator finds time to draw it in the program so hopefully by next week I'll get that. And I need to build an exhaust guard for my leg

    But tonight I took her out for a test run and holy shoot!! She takes right off!! You need to lean forward like a crotch rocket or else you're on the ground! I don't think I even took it past half throttle and was already going faster than I need to go. Pretty excited!

    .wee..duh.
     
  6. Tony01

    Tony01 New Member

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    Nice! Very nice!!! So what is your gear ratio starting from the cvt output sprocket?
     
  7. scotto-

    scotto- Custom 4-Stroke Bike Builder

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    The only downside I see to the engine mounting here is you won't be able to adjust the valves without removing the engine from the frame. Just something to think about for ease of maintenance.
     
  8. Amarion1

    Amarion1 New Member

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    CVT is a 12 tooth going to a 24 tooth. Then a 9 tooth to a 50 on the wheel
     
  9. Amarion1

    Amarion1 New Member

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    I am able to remove the valve cover to make the adjustment but I can't remove the spark plug at that angle. That is a winter project though is to move the motor down a touch so I can read and replace the spark plug ☺
     
  10. scotto-

    scotto- Custom 4-Stroke Bike Builder

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    "Reading" and/or replacing spark plugs on these 4-stroke engines is not really necessary compared to adjusting the valve lash. I've been racing my current 215cc Predator engine for over 4 years now and haven't had to change the spark plug yet.

    The engine has 62 hours on it now....hard racing and pushing 9,000rpm at times while putting out around 25HP.

    Originally I ran the GTC Torque Converter set-up on my race bike until the horsepower was exceeding 15HP and started smoking the belts. Now I run a 2-disc cent. clutch and no more broken belts.

    [​IMG]
     
  11. Amarion1

    Amarion1 New Member

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    Thanks that's nice to know about the plug!

    Your build is what inspired me to do mine. Your bike is super bad ass

    I was originally going to use that centrifugal clutch set up but I had this cheapo torque converter already so I'm seeing how I like it. So the AGK calculator says my gearing is 11.111. Do you have any recommendations for gearing so It doesn't always want to pull the front wheel off the ground on take off? I'm also working on figuring out jetting on this so I can tune my carb correctly. I drilled it enough to kick over and idle but once it's warm I need to turn in the idle adjustment or she dies and when cold I have to back it out or it takes off on me

    Thanks for any advise!usflg
     
  12. scotto-

    scotto- Custom 4-Stroke Bike Builder

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    Thank you for sharing you build and putting in the time and effort that it takes to get it right. The gearing is much easier than the jetting to get right, that's for sure.

    I really like running 11.11:1 for my tall gearing so to speak. With the TC set-up it worked great and did keep the front wheel down a little easier than lower gearing. With my current set-up that is about as tall of gearing I can use at the track and get away with as the tracks are fairly short and tight.

    Ratios of between 10.41:1 and 12:1 are what I play with on this race bike,it really depends on the track and the conditions. Jetting on the other hand is whole different ball of wax to deal with as elevation changes things as well. Just experiment and take notes with making changes in small increments.....be very patient no matter what, it will pay off in no time.
     
    #52 scotto-, Oct 7, 2016
    Last edited: Oct 7, 2016

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