Carby newcomer, carb jet question

Discussion in '2-Stroke Engines' started by Pokernliquor, May 23, 2011.

  1. Pokernliquor

    Pokernliquor New Member

    Hello everyone, thanx in advance for any input you can offer.
    My first build, everything on order, nothing arrived yet... I ordered a 66/80 2stroke, 50 tooth sprocket, and fancy poo poo pipe.
    Here in wisconsin motor bikes cannot go over 20mph with 150lb rider on flat level ground no wind. i want to b well within the law, and i want to be quiet. From the research i've done on this and other site's the fancy poo poo seems to b the quietest, and also improves low end torque. The 50 tooth sprocket improves low end torque and reduces top speed. I weigh 260lbs, my theory is with the poo poo/50 tooth I will have a much lower top speed and more umpfff to haul my big butt around. Cant find a "fancy" poo poo video anywhere to hear how it may sound?
    Question is this... 150mile breakin period with higher oil/gas ratio... does anyone know if i should automatically re-jet the carb for running too rich or lean? I'd hate to break it in with the wrong setting, assuming i would get a false read from the break in mixture of gas/oil.
    in other words is the fancy poo poo pipe known to give me a rich or lean mixture that i can deal with immediately at install so i dont damage my motor during break in period?

  2. SlugMan

    SlugMan Member

    I would just run the recommended oil/gas ratio for the break-in period, with your exhaust. Do a 'plug chop' to conferm your not running lean, then break it in. After you have broken in the engine, play with the carb settings to figure out the best settings for whatever mixture your gonna stick with.
    In theory the 'Poo-Poo-Pipe' has less restriction then the stock exhaust, allowing for more air to flow through your engine. Which makes the gas/air ratio leaner, or less gas&oil per volume of air.
    In my experience the straight pipes are kinda LOUD! Compaired to the stock muffler.
    Last edited: May 23, 2011
  3. sparky

    sparky Active Member

    See my sig to know how I feel about "torque"!

    Any exhaust that is giving you MORE performance is going to be louder. Any example vids might not help you out as you'd need the same camera/mic recording two different mufflers on the same engine!!

    And I'm not sure about the fuel/air ratio with new pipe, but just adjust it 'til it revs right.

    Also, not sure about any 150 mile break-in. But you should only be mixing 1 gallon of gas at a time!! Soo... 1 gallon = 1 break-in.
  4. motorpsycho

    motorpsycho Active Member

    the poo-poo pipe is not a straight pipe.
    it has a standard style baffle / end cap just like in the stock mufflers.
    the muffler body on a poo-poo is longer than the stock muffler.
    by rights it should be as quiet or a little quieter than the stock pipe.
    I have a poo-poo pipe and i modified the stock baffle and shortened muffler case.
    it's louder than stock, quieter than a straight pipe.
  5. SlugMan

    SlugMan Member

    Ok, I was thinking a straight pipe. I was wondering what was ment by 'Fancy'.
    Thanks for the clarification :)
  6. Pokernliquor

    Pokernliquor New Member

    thanx for all the help everyone...
    the "fancy" poo poo pipe i ordered is from kings motorbikes. there are poo poo's that "appear" to be a stock muffler, just with more pipe between muffler and engine. That way it exits behind the rear axle.
    The "fancy" poo poo "appears" to be different design all together. it has a more rectangular shape to it. I have searched many hrs on youtube, and forums like this one. The only info i could gather was it improved low end torque and was quieter. one fellow said it was the quietest exaust he has heard, and claimed to have built many bikes.
    Again if it's known to make me run lean, I'd hate to break it in that way... less oil is more wear at the crutial break in stage... I dont have your experience, that just seems to make sense... thanx again for any advice
  7. RedBaronX

    RedBaronX Member

    FYI, the speed limit is not 20, it's 30 mph in Wisconsin:

    (4) "Automobile" means any of the following: 340.01(4)(a)
    (a) Type 1 is a motor vehicle designed and used primarily for carrying persons but which does not come within the definition of a motor bus, motorcycle, moped or motor bicycle.

    (b) Type 2 is a motor vehicle capable of speeds in excess of 30 miles per hour on a dry , level , hard surface with no wind , designed and built to have at least 3 wheels in contact with the ground, a power source as an integral part of the vehicle, a curb weight of at least 1,500 pounds, and a passenger and operator area with sides permanently enclosed with rigid construction and a top which may be convertible.

    (30) "Motor bicycle" means a bicycle to which a power unit not an integral part of the vehicle has been added to permit the vehicle to travel at a speed of not more than 30 miles per hour with a 150-pound rider on a dry , level , hard surface with no wind and having a seat for the operator.

    (7) "Motor vehicle" means any automobile, truck, trailer, semitrailer, tractor, motor bus or any self-propelled or motor driven vehicle, except a motorcycle, moped, motor bicycle , electric personal assistive mobility device, or vehicle operated on rails.
  8. rustycase

    rustycase New Member

    I don't necessarily believe the uber thick oil mixes are good for a new engine during breakin.

    IME, most the oil available today is far superior to all the old-school mixing oil.

    I run a fat mix for the very first run in, but change shortly after that when I can 'feel' the engine free up, and actually run quieter, and cooler.

    I believe in running rpm up, and down, with an opportunity for it to cool at lesser rpm's following periods of acceleration under load.

    Super-synthetics are probably NOT the best option for break-in.

    All told, good advice posted above...

  9. SlugMan

    SlugMan Member

    I have the same engine as you, the 66cc Grubee. With my 44 tooth sprocket I can get it up to 30 MPH at WOT. FYI
    Plus, it still has enough power to climb hills. I'm 220 lbs. What helped me out alot was the high compression head with a better carb. Makes that little popcorn machine come alive. I live in Maine and we have a lot of hills in the area. I'm pretty much located in a valley, gotta climb up to get outta here :)
  10. Pokernliquor

    Pokernliquor New Member

    thanx baronX, and for the other replies... I'll double check that on the 20 or 30mph though your probably right. I hope so, I would rather have the extra mph for when i do country rides. now if i can just get Kings to communicate with me just once! I may be able to find out where my order is... email they sent was on 5-9-11 that it shipped. FedEx tracking says its only initialised, not picked up, not in transit, not delivered. 4 emails and 2 phone messages left and still no response... jeeeze...