2-stroke/single-speed...operation for topend performance?

Discussion in 'Performance Mods' started by augidog, May 1, 2008.

  1. augidog

    augidog New Member

    golden eagle system, 14tooth drivegear, 60lb bicycle/195lb rider...topend of 37mph...

    tanaka 32cc purefire, upgraded to 12mm carby (from 10mm) & boost-bottle. stock crank and porting. E3 spark plug and tuned stinger extension (on stock converter/muffler) are pending.

    the main reason for the carby-upgrade was tunabilty, as it has the high-rev mixture screw available...when the rear wheel is off the ground (no load) i can make it scream in either a lean or rich condition, but under load neither (extreme) setting will pull worth a dang. i'm hoping the E3 plug will help me with that.

    with no gearing, the engine has to be kicked in by the time i've pedal-assisted up to 20mph, and it has to be tuned to achieve maximum rpm from there...i have a mile to reach topend, but it doesn't seem as if i need that much room.

    so, what should i do? i added a piece of tubing to the screw so i can adjust mixture while running under load, but i'm noticing no real bump in maximum performance, there seems to be only one setting that makes it right for all conditions.

    am i missing something or am i just going to have to admit i've hit the ceiling for this engine? is the boost-bottle (which is about 1/3 too large by volume) affecting topend?

    i look forward to some serious discussion about carby-settings, boost-bottle, possible high-perf fuel...no need to tell me to start shaving metal off, no internal mods will be done on this engine...remember i need to be able to road-ride this when i'm finished racing, i can't be blowing it up...thanks :cool:
    Last edited: May 1, 2008

  2. Jim H

    Jim H Guest

    Augi, have you seen the offset woodruff key that advances the timing on these motors? They increase engine rpm...think I saw them on some scooter sites that use these type engines.
  3. augidog

    augidog New Member

    i have seen 'em, have been looking at some karting sites where tanaka seems to be quite popular, and have pondered the mod for a future build, but there doesn't seem to me much benefit unless there's some porting involved...and i get plenty of revs, i just can't seem to create any more power in the combustion chamber.

    my goal this time out is to showcase a "stock" engine/drivetrain...the larger carby isn't really a bump if one were to gear down and go after more torque at 30mph. i could climb a tree with the 12tooth drivegear...

    next year? well, we hope after our showing this year to attract some serious sponsorship...
    Last edited: May 1, 2008
  4. ocscully

    ocscully Member



    Any chance you have the RPM at which that 37mph was recorded? jpilots ratio calulator would indicate 9100+ rpm. Do you feel you were reving that high? The numbers I used in the calculator are the 14t driver you mentioned and then I calculate the GEBE Sheave to be the equivlant of 267t for a total reduction in the 19:1 range. Please don't take this question as me saying that you are wrong or in error I'm still just trying to understand the differences in reported top speeds and the math used in ratio calculator.

  5. augidog

    augidog New Member

    maybe santa will bring me a "tiny-tach" next x-mas, but...

    yup, i'm getting some good revs...dennis says the engine can handle approx 12k, but putting some power behind the revs is a different story...
  6. augidog

    augidog New Member

    so...this isn't like an engine that would be asked to perform throughout it's range...but only as rpm's increase...like i should be able to make fine-tunage as momentum steps in...much to learn.

    any tips, secrets, links?
  7. I'm no expert but it sounds like you're hitting a dead spot at speeds?
    Sometimes dropping the gear by just a tooth can help that rut even if it means higher RPM on top.
    Like when I read car magazines on top speed runs. Most cars top speed happens at a lower gear than what the tranny has in gears. Fourth gear gets you to top speeds but when they shift to 5th it drops.
    It would be cool if you can hook up your engine to a dyno then you know at what RPM your engine is making the most power. Then you gear according to that RPM,to get you to top speed at that RPM.
    Last edited by a moderator: May 1, 2008
  8. augidog

    augidog New Member

    changing drivegears takes only seconds, and worthy of experimenting...thanks fer knocking my brainpan around...tune for fat r's but drop down to give it more advantage, sounds like fun...i know we're only guessing, but it feels right :cool:

    no real ride-time this weekend, tourist influx for a "clam-tide", i'll lay low until monday and get fresh fuel, maybe my E3 plug will be at the post office then...

    one thing, there is a custom 16tooth heading my way, so i need to find the most powerful top speed under the current load, then hope i can still squeeze a bit more when i gear up..whatever happens, i will let ya know, tho :)

    anyone who has the tip i need to maximize performance once i reach maximum r's, or to find that balancing point, please clue me in.
    Last edited: May 1, 2008
  9. augidog

    augidog New Member

    for anyone who really wants to get into it, here's the pdf i got from walbro's site...not sure if it's the exact one, but the construction and illustrations are:

    Attached Files:

  10. sawman

    sawman Guest

    Swap out your coil. (no rev limiter)
  11. augidog

    augidog New Member

    sawman...you waited almost a year to post, then it was here of all places...i feel like i should take the suggestion seriously. i've been searching for tanaka performance parts, i find carbs and pipes but no ignition...can you tell me anything specific, please?
    Last edited: May 2, 2008
  12. sawman

    sawman Guest

    Zenoah G23LH coil...Daves discount motors should have it.i also have a tanaka mine hit the rev limit and mine is built to the max.i know i'm suppose to introduce myself first i will later when i have time. just thought i could help you out.
  13. augidog

    augidog New Member

    hey, i don't run the place, i don't care where you post ;)

    i was tickled that you felt like jumping in to help...i will be researching, soon as i post this "thanks" :cool:
  14. kawasaki999

    kawasaki999 Member

    drop down to the 13 tooth, index the e-3 plug, and then theres the nitro blast ingnition, makes a powerful spark.
  15. augidog

    augidog New Member

    i have plenty of spark...spark is not a problem, the e3 burns whatever i can throw at it and the electrode is so clean i get scared i'm running too lean. i'm about 3/4 turn richer than the recommended preset, and it sounds great, but i'm still getting no power to attain and sustain potential top end.

    boost-bottle's coming off today for a couple of runs...as i mentioned it's about 33% too large anyway, and i'm ready to grasp at straws. still much to learn, i think i may have to start from scratch and upgrade more methodically next time.
    Last edited: May 3, 2008
  16. kawasaki999

    kawasaki999 Member

    www.bladezscooters.com read about the nitroblast ing. you spark is good but it will be 3 times better and a big gain in power. I have a tanaka 47r and I can get more top end with the 13 tooth than the 14 but I have 26x2.2 tires. let me know your results if you try this. also when you run a the salt flats run and tune without the air filter but I would not run without it too many times. I run my airplane motors without filter all the time with no problems.
  17. Rob928

    Rob928 Member

    Just starting on the bicycle engines but have been racing and riding motocross all my life.

    My tanaka 32cc should be here friday so not really sure of the workings of the motor yet.

    Just things that could normally cause these things in a 2 stroke, Does the carb have low and high speed jets? Have you read the spark plug?(is it wet after a high speed run or white)? Is the needle adjustable ? What kinda altitude does the carb come pre jetted for compared to the elevation you live?

    Just some things to consider,
  18. augidog

    augidog New Member

    hi, rob...you are soo gonna luv the tanaka...it's 2-stroke rocket-science.

    i'm at completely sea-level. i have no idea where the carby was born, it's a basic 12mm walbro w/high-speed adjustment.

    idle mixture inside barrel, set to just-rich.

    high-speed mixture is very touchy...no-go on anything over the line towards lean, great lowend-pull when rich, but doggone it i can't get any rpm's. when it's freewheeling it just screams, so i know it can do it.

    a brand-new e3 spark plug looks very nice, always dry...it's just getting tan along the index-line.

    so i keep going rich, it keeps burning it, but i ain't gettin' any speed.
  19. Rob928

    Rob928 Member

    How about the pipe? are you still running the stock pipe?

    Maybe with the bigger carb the stock pipe is hindering performance, might look into a tuned pipe for your needs/wants.....

    Just a thought.

  20. augidog

    augidog New Member

    yeah...stock muffler/convertor/spark arrestor...all clear and flowing.

    dennis says i should try a 1 1/8" stinger extension, so you seem to be on the right track.

    my goal is to run as close to stock as i can...i really want to be able to say i did it with the catalytic convertor in place (epa/carb compliance is important to the club)