Break In Throttle and break in tuning.

Discussion in '2-Stroke Engines' started by deercrossing, May 22, 2007.

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  1. deercrossing

    deercrossing Guest

    Hello, having put the engine on my bicycle I need help to get the throttle set right. I seem to have to much slack on both ends. Should there be some slack at the throttle or carb? Motor boggs and hills are not very good. Is this just brake in running? Motor came with no direction about how to adjust carb or how to set engine for best results. Anybody want to tell me how they tuned up for first 500 miles break in? I've done some research on this site and see there are some very good Motor Heads out there! Thanks for any help passed on.

  2. gone_fishin

    gone_fishin Guest

    for the throttle-cable slack:

    assemble everything.

    holding the throttle closed, use the cable adjustment on top of the carby, tighten up on the cable housing until there's zero play in the housing.

    check the throttle for full travel. if it's good, lock the adjuster. done. if you make any major adjustment of the "idle screw" (i almost said "mixture" just to get joe's attention :lol: ), you may have to re-do the cable adjustment or not.

    let us know.

    about break in opinion: there's a ton of break-in topics going, anyone have a favorite?
  3. Guest

    Guest Guest it fairly rich (3rd slot from the bottom) and run it like you are on a low speed racetrack. That is lots of throttle postition variation, and lots of moderate loading/unloading of the engine with low to moderate rpm. No real high rpm until the first tank has been run through it.

    BTW- I don't think it's really 500 mile of break-in running, that may be a misprint. I personally run one full tank of gas @24/1 mix, then run the second one with 32/1 and finally go to the permanent solution of 40/1 good quality two stroke oil for AIR COOLED ENGINES, no outboard oil please!
  4. rcjunkie

    rcjunkie Guest

    For break in run 25:1 on oil ratio and run mixture at normal (not lean or rich) setting. Employ full rpm range once engine is warmed up and vary engine throttle and engine load so engine sees ENTIRE rpm range from low to max rpm. Do not maintain constant engine speed/load for first tank or two. Need to get those high rpms because with increasing rpm, the connecting rod actually elongates a little and piston actually goes a little higher up into the cylinder with each stroke.

    If you do not break in an engine at higher rpms then you will have wear in the jug where piston "travelled" but not at the location where it travels when rpms are high. This causes a taper of the cylinder which can damage a piston and break a ring when you finally decide to to to max rpm after a couple of tanks.

    Running engine too rich means it will not reach normal (expected) operating temps which are important in break in process. Running engine too lean will damage it.

    Before starting a new engine, pull jug and flush out interior. You may also want to put some assembly lube on connecting rod bearings and spray some oil on the cylinder wall. First starts may take a little longer than normal and nothing worse than starting a dry motor.
  5. Guest

    Guest Guest

    Not recommened for newbs and folks who don't have a little small engine background.

    Use some Marvel Mystery Oil or regular two stroke oil in the spark plug hole and intake before you start it.

    Also, work you way up to those max rpm, don't just zing the engine up to your (estimated) redline. Give the engine little time to warm up.
  6. Guest

    Guest Guest

  7. BikeHacker

    BikeHacker Guest

    Dont let them idle they are not crank case induction engines ... blip them awake to send sprays of oil down to the crank... If you back your idle screw all the way out and it still runs you have an engine killing ring melting port trashing nickel flash chipping intake leak ... kill switches are aptly named
    I put my last 2 stroke to sleep with a full throttle 40mph ride on a 48T sprocket ... nighty night... I love killing these engines ... i have personally destroyed 10 but i tell you they like high performance mods more than the 3 four stroke engines i have killed going for 55mph on a 48T sprocket
  8. Guest

    Guest Guest

    I let mine idle all the time, no problems.

    Perhaps you'd like to explain the way these or ported and how idling kills them?

    If you love killing these engines perhaps you love to share your bank acount with me?
  9. Guest

    Guest Guest

    BTW- "whatchootalkinaboutwillis?" Is the sound of my BS meter going off.
  10. gator joe

    gator joe Member

    I used Yamaha lube I understand its for a water-cooled motor but I know it's a very high quality oil I should probably switch 2 Honda 2 stroke oil what do you think and why not use outboard oil other than the fact that their water cooled its a semi synthetic and a very high quality oilI did run even more oil than 16 21
  11. gator joe

    gator joe Member

    Thanks guys great info here
  12. gator joe

    gator joe Member

    First of all how much slack r we talking about. Is it about a quarter turn on the throttle. Let me guess u notice it more when starting. And the bike allways shuts off when sitting in idle. If ur not paying attention to giving it a little throttle. And as far as the bogging. They tend to go thru that especially in break in period. It won't do it as much when motor is nice n hot.but let me give you some advice. Dont short cut the break in period. It's the most important part of anything u do to the motor. Dont run any faster than 15 or 20mph. No more than 20 minutes at a time and let it get ice cold after each ride . On the bottom of your second tank open it up let it rev up just a little bit for short bursts it will elongate your piston extension and give you more power in the long run