99cc hf predator engine with a gtc tc2 cvt

Discussion in 'Spare Parts, Tools & Product Developement' started by tfpent, Apr 17, 2011.

  1. tfpent

    tfpent New Member

    Hello, Is anyone considering this setup? if so what are your concerns? also could someone give me a detailed link to making this engine convert over to a twist throttle from the generator style throttle it comes with. thanks

  2. tfpent

    tfpent New Member


    any ideas out there? Is the cvt needed or should i try to go straight to the rear sprocket?
  3. MikeJ

    MikeJ Member

    tfpent -

    I am considering this engine for my current build. But... before I can go much farther, I need to know the external dimensions of the engine (it may not be mountable in my bike's frame). And you may have to be patient to measure an engine for yourself. You must take into account pedal crank clearance if mounting the engine in the frame, and centering offset if going with any mounting configuration.

    I have yet to read of anyone mounting the Predator 99 cc. (It is not scheduled to be available at the local Harbor Freight store until May.) I have my own way of mounting the throttle cable, at least one other reader has a different way. They both work. Photos are provided in the 4-stroke section. You will find them with a little looking around.

    There are lots of ways to mount an engine and get power to the rear wheel. Do some research on this forum for the many ways of making that happen. It would be foolish for anyone to tell you what is best for you until you can provide a lot of details. Then we can offer ideas. Then you decide what is best for you.


    TREEWK Member

    One System I Have Been Thinking Of; The 98 Or 99cc Eng, Sbp 4 Stroke Motor Mount And Their 4 Stroke Jackshaft Bracket. Use A Primary And Secondary Belt. Use A Whizzer Type Rear Sheave. Think How Long A Fan Belt Gives Trouble Free Service.

    I Would Prefer Using A Solid Small Pulley On The Crankshaft. Use A Spring Loaded Front Belt Tensioner Pushing Up On The Bottom Of Belt. Use A Latchable Clutch Lever And A Cable To Pull Against The Spring Tensioner, To Loosen Belt For A Clutch. Not Much To Go Wrong In This Type Of System. I Like The Thumb Throttle With The Dual Brake Lever, $12.95 On Ebay Free Shipping. Have That On My Shifter Bike And Would Not Consider Any Twist Throttle Junk!! Imho Lol.

    PS I would use 98cc rather than 79cc greyhound, easier to mount with the upright cyclinder. A spring loaded belt tensioner on the rear would be excellent also, never have to adjust belts and you don`t have the tite/loose spots from things not being perfect.

    I have two cvt builds. With the 98cc i don`t think a multi speed would be needed. you can change ratio`s by changing one or both jackshaft pulleys

    Thats my story and i`m sticking to it!!
    Last edited: Apr 21, 2011
  5. tfpent

    tfpent New Member


    Do you have a link for the thumb throttle with dual brake lever? I can't find it on ebay.

    TREEWK Member


    The Thumb Throttles Are So Smooth And Well Built. They Have A Throttle Stop For Full Throttle Adjustment= Saving Carb And Cable From Excess Stress. There Is An Idle Adjustment Also.

    I Did Not Find The Dual Brake For $12.99 With Free Shipping This Morning, That Was A Great Bargain!! They Come With The Brake Lite Switch And Cable Built In.

    The Higher Price Model Is Listed For Bigger Motor Cc. I Think They All Use The Same Size Handle bar Dia. Send Them A Message Asking For The Best Deal They Can Give You With Shipping. I usually get a better deal than expected!!

    Hope This Helps. Ron

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    Last edited: Apr 26, 2011

    TREEWK Member

    Someone Has Used That Motor In A Mab Recently. They Thought It Easier To Mount Than The 79cc Because It Has The Up-right Cylinder . May Have Been On The Other Forum.

  8. MikeJ

    MikeJ Member

    Pictures of the 99cc Predator has its cylinder angled out at around a 45 degree angle if this is what you mean by upright. It is an oversized 79cc engine. I have at least one inch clearance front to back and top to bottom, so the 99cc engine will fit my bike. A vertical cylinder model is too tall for me.

    TREEWK Member


    Thanks For Posting That Info. I Guess The Engine I Was Refering To Is A 98cc Valve In Cylinder Motor. I Must Have Thought He Meant The 98cc. I Was Not Aware Of The Two Different Motors, His 99cc. My Bad!!
  10. samuari86

    samuari86 Member

    i going to the 99cc motor after i get done trying to blow my 79cc motor up. just posted this today,go to Frame-Mounted Drive-Trains take a look

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  11. TREEWK

    TREEWK Member

    It Looks Like You Should Succeed!! Lol Thats Cool.
  12. samuari86

    samuari86 Member

    i hope i do thin i can go to the 99cc motor
  13. loquin

    loquin Active Member

    The two things I would be concerned with are
    1. weight/size: these motors will weigh close to 20 pounds dry... BTW - the 99cc Predator looks like it has roughly the same cylinder angle as the 79cc Greyhound - about 15-20 degrees from horizontal.
    2. legality. Many states that allow motorized bikes to be unregistered have a 50cc displacement limit... Otherwise, they have to be registered as mopeds.
  14. Richard H.

    Richard H. Member

    And valid concerns they are though I'd wager they'll go little heeded.

    On the weight question, when the specs were listed the 79cc engine had a dry weight of 24 lbs while the 99cc is not showing weight. For the later, wouldn't we be talking about something around 30 lbs with oil and fuel?
  15. mbatl

    mbatl Guest

    Sounds like a beast in terms of bicycles lol.
  16. RdKryton

    RdKryton Active Member

    How are you going to lubricate the turbo? They need a pressurized oiling system to keep from burning up and the HF79cc engine does not have this. Just curious.

  17. samuari86

    samuari86 Member

    yes the turbo dose needs oil and it dose need to be pressurized, thats way im still not for sure if its going to be mechanical oil pump or elactrical, willlllllllllllllllllll see how im going to do it :)
  18. samuari86

    samuari86 Member

    well seeeeee.im working on it rigth now,:)
  19. buzbikebklyn1

    buzbikebklyn1 New Member

    Far out man! the turbos almost bigger than the engine... i think you might need a smaller exhaust housing... i don't think that's got the exhaust volume to spin that compressor.
    please let us know if you do it i wanna see it!