tanaka pf 4000 performance tip please

Discussion in '2-Stroke Engines' started by dirtwarrior, Oct 21, 2014.

  1. dirtwarrior

    dirtwarrior Member

    This engine is rated at 2.2 hp. With minor intake and exhaust changes can it make 3 hp?
    What intake and exhaust changes can be done?
    Last edited: Oct 21, 2014

  2. piecepatrol99

    piecepatrol99 Member

    I would first make sure you don't have any leaky gaskets or seals.
    I added a boost bottle kit and everything that was minorly off with my motor was amplified by the modification/addition of the bottles.

    Fisrt was a high idle issue. I adjusted the carb needle down to thin the mixture to get the idle back to normal. That didn't do it.
    Next was drill and tap the stock manifold for the NPT fittings. The manifold that came with the bottles had a narrower throat by 1/4". That helped but still didn't do the trick.
    I found a head gasket leak after coming to the forums for advice. Sealed it, saw little improvement in the idle. Still either racing or stalling when I disengaged the clutch.
    I drilled out the tailpipe of my muffler end cap as I saw the port being about 1" and the tail was 5/16". Drilled it out to 1/2" and bypassed the baffles. More low end torque, smoother running but the idle was still higher than stock.
    Finally some one said check the carb for leaks. At first I said been there, that can't be the problem. Then the light came on...every time I touch the carb, the nut that holds the throttle cable is loose. Only a 1/4 turn but loose. I put a rubber washer in it. Idle is back to normal, no more intake leak...but now I get to play with the bottles and jets again.

    It may have to wait til next summer as I know the motor changes in performance with every 15degree drop in temp.

    I've heard a lot of mention that almost any carb is an upgrade from the NT I'm using. Most tallked about are the speed and delorto (hope I spelled that right).

    Wether its 2 stroke or 4 stroke, best thing I can tell you in my humble opinion is what ever you do to the intake, do something to the exhaust to match it. Especially with these small engines. 2 stroke not having valves to close the combustion chamber are dependant on the exhaust being matched to the intake to maintain compression and fuel mixture.
    dirtwarrior likes this.
  3. dirtwarrior

    dirtwarrior Member

    Thanks for the reply. Do you think 3 hp is easy to get?
  4. piecepatrol99

    piecepatrol99 Member

    I'm not sure about hp ratings...I'm going but seat of the pants measurements.

    I can tell you from my own experience the boost bottle does work. But I'm still playing with it to get peak performanc out of it...
    In addition to the bottle, I bought a set of carb jets from thatsdax.com
    The initial install of the bottles made the motor race at idle. Turning it down byt the screw on the carb just made it stall out.
    You have to move the C clip on the carb needle up for sure.
    Next makes sure you have no leaks that cn throw off your fuel/air mix. That will also make the idle race. Installing a flat rubber washer in the throttle cable nut should take care of that.
    Next thing I had to do was drill out my tail pipe from 3/8" to 1/2". That helped but I'm still 4stroking at high RPM range.

    That's where I am right now, I've been taking care of other issues and haven't had time to play with the motor in lue of replacing the bike.

  5. darwin

    darwin Well-Known Member

    Those goped guys have tricked out those 40cc motors to the max. It's interesting to see what those kids can do. Our future technicians a lot of them.
  6. dirtwarrior

    dirtwarrior Member

    I don't want to exactly max it out. I got to balance cost, reliable, and factors. Being an old hot rodder I can't leave it stock.
  7. darwin

    darwin Well-Known Member

    Just hinting at some other sites that kinda sorta specialize in answering your question...............good luck buddy!
  8. dirtwarrior

    dirtwarrior Member

    got any links
  9. piecepatrol99

    piecepatrol99 Member

    IMG_20141022_112109.jpg IMG_20141022_112228.jpg


    This is what I've been working on since 8am this morning.
    I've got a vertical dropout deraileur mounted to a bike with a horizontal dropout. Not big feat...

    I'm stuck on my front freewheel, getting everything to fit, clear and function.
    Right now the rear derailuer is only an 'automatic chain tensioner'. I don't have the tool to swap the single speed freehub that's on the wheel for the three speed freehub that came in the mail today.
    But I am going to get my top end back (I had on my cruiser before the fork broke) by way of the third chainring I just installed on thr front freewheel and front derailuer.
    The deraileur fits behind the right side chain tensioner no problem.
    My hiccup lays in the spacers I removed from the freewheel making adding a third Cr possible have also allowed the CR hardware to hit the chainstay behind the bottom bracket.
    Time to take it all apart to install a 2.5mm BB spacer, and I'll be ready to install the shifter and cable and go for a test ride ;-)

    The 3speed freehub will have to wait til I can get to the bike shop to have it swapped and find out what tool I need so next time I can do it my self...

    For now, my flip flop fix has become a motorized 2 speed. I have to pedal to take off but I should cruise at about 30 to 35mph.
    Hopefully by this time next week, it'll be a 6 speed and I can take on some hills :p