Warning / Gp460 Users / Warning !!

Discussion in '2-Stroke Engines' started by DetonatorTuning, Aug 25, 2008.

  1. DetonatorTuning

    DetonatorTuning Active Member

    DO NOT GO LEANER ON OIL THAN 25.1, PERIOD ,EVER, NEVER !!

    my engine was runnung very well and i decided to try leaning the oil down. went to full synth Amsoil saber pro and mixed it 75:1 which had been rumored to be equal to about 37:1 reg. oil.

    this was all my fault, i knew the DDM techs have said to NEVER go beyond 32:1 no matter what oil.

    so tonight after putting 18 hrs. into reconfiguring to my Staton verticle gearbox drive system i go out and run the bike and in the process burn a hole straight thru thr top of the piston. LOVELY.

    now i have that to fix. AND i already HATE the gearbox. i guess i just underestimated the power loss, vibration and noise. got to figure something out to dampen that whawhawhawha chain oscilation for sure.

    ride safe,
    steve
     

  2. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    ****!!! That sucks....
    Steve you are a pioneer on these set ups pushing the limits and I really
    appreciate your feedback
    I still think belt drive is the way to go and there will not be one GEBE part
    on the bike
     
  3. arceeguy

    arceeguy Active Member

    Well, so much for ScAmsoil.

    Sorry for your loss.

    I was taught that it is better to have lots of marginal lube than trace amounts of "good" lubrication. A respected mechanic (and friend of mine) once said - regardless of what you think, your engine would rather have 5 quarts of dirty, used oil vs. 1 quart of the worlds finest synthetic (or whatever) oil. 75:1 equivalent to 37:1 - Marketing at its finest! A few years back, I bought some 2T oil that claimed you could run 100:1 in any 2 stroke application. It was expensive stuff, but I didn't have the guts to do it. Didn't have the heart to force my engines to dry hump themselves to death. :D
     
  4. Easy Rider

    Easy Rider Guest

    The 460 is a popular motor for go-peds and go quads. I've seen a few of 460 cylinders at the shop. All of them suffered the same problem. The chrome on the cylinder would peel off.
    Also the pull starter aren't the best of quality either.
    I think if I was to ever build a bike like the ones that use these types of motors, I would use a Zenoah 40 or an Active 52. Those motors are pretty reliable.
     
  5. spad4me

    spad4me Member

    Use a roller blade ball bearing wheel on the unloaded side of the chain to dampen the oscillation.
    search for chain adjuster
    What type of lube is in the gearbox?
    Royal purple is the only oil to actually increase horsepower, due to less frictional loss in gear boxes etc.
    A stethoscope, or a long screw driver can be used to find a noisy bearing.

    Glue carpet on the outside of the metal housing to dampen the noise.
    What type of oil you use in your engine is up to you.
    I use a castor synthetic mix. Just went from 16 to 1 to 25 to 1.
    But the temp here is 110 + . I use more gas due to evaporation, than to engine consumption.

    Be sure to remove the all the melted metal from the crankcase.
     
    Last edited: Aug 26, 2008
  6. Pablo

    Pablo Motored Bikes Sponsor

    I highly doubt 75:1 caused a hole in your piston. If the engine siezed, top or bottom maybe we would be talking about blaming the oil. Are you sure the carb isn't too lean?
     
  7. Pablo

    Pablo Motored Bikes Sponsor

    Also, as far as MB 2 stroke oil mix - I have never recommended anything leaner than 50:1 for these sometimes highly loaded, sometimes very high RPM engines. For Saber or any oil. So I'm "just" a dealer, WTF do I know? Well rather than spew my credentials, I will tell you a different way: People on their own have contacted Amsoil Tech services to ask what they should run with Saber in all sorts of MB engines. 50:1 max.

    The 100:1 recommendation is for small precision engines with varying, but not extreme loads.

    As for this engine - no never would I have recommended 75:1. These engines are not problem free, the chrome cylinder just being one issue, and to immediately blame the oil may be premature. Some people get their jollies blaming Amsoil, so I'm used to that. Calling names just proves their immaturity and lack of technical knowledge.

    25:1 with Saber would be rediculously oily for street use, and for racing I don't recommend Saber. Use Dominator at 25:1.
     
  8. Easy Rider

    Easy Rider Guest

    I agree with you Pablo, It's not the oil that makes the chrome peel.
    It's the quality of the motor.
     
  9. DetonatorTuning

    DetonatorTuning Active Member

    well i can see this is going the same way as my unwise comments about the Staton clutch drum !!

    now listen, I SAID, THIS IS MY FAULT AND MY OWN PROBLEM.

    I DID NOT SAY THAT THE USE OF AMSOIL WAS ITSELF, NOR A CONTRIBUTOR TO THE OUTCOME. iguess i'm guilty of leaving it open to assumption though . for that i'm sorry.

    Pablo, i hope YOU understand that i was NOT implicating or accusing toward AMSOIL products .

    I WAS PREVIOUSLY USING THE SABER AT HIGHER CONCENTRATION AND HAD FINE AND SATISFACTORY RESULTS.

    I DID SAY THAT WHILE USING ANSOIL IN AN INAPPROPRIATE MANNER I BURNT MY PISTON AND THE CYLINDER PLATING IS IN THE BOTTOM OF THE CRANKCASE.

    I AM LOOKING AT THE FUEL MIXTURE SCREW SETTINGS TOO, and it's my bad for not mentioning it in the first post.

    THE MAKE AND TYPE OF OIL IS IRRELAVENT OTHER THAN THE FACT THAT I DIDN'T USE IT PROPERLY.

    kind of like my original build thread, i have made the subject of this one clear enough. those of you that want to change it or argue your opinions of OTHER matters are invited to start another thread.

    how was that ZevO ? even Hoosierbilly can be taught, whoda thunk !

    steve
     
  10. DetonatorTuning

    DetonatorTuning Active Member

    thanks, shoot me a PM sometime outlining some of your ideas.

    DON'T TELL ANYONE I'M ALSO LOOKING AT A HOMEMADE BELT SYSTEM !!

    steve
     
  11. Pablo

    Pablo Motored Bikes Sponsor

    DT - no issues. In fact your first post was not blaming the oil in particular, and I have no issues with that. People who pile on sorta get my hackles up.

    One cool thing is we learn from situations like this. Expensive lesson for you, I know. Sad to say, I'd love to inspect "the evidence".
     
  12. DetonatorTuning

    DetonatorTuning Active Member

    the evidence is a hole thru the center of the piston, white ignition blast on the top of the connecting rod, the rod bearing lubed and free moving, the whole bottom end lubed and totally free. a plug real nice biskuit brown with chrome flecks all over it. no carbon build up anywhere.

    the piston skirt dark and scored,the ring sticky and hanging up the groove, and the cyl. plating all down in the bottom of the crankcase in little BB's.

    as of now, i'm saying i had the fuel screws too lean. i'll never know, i'm going to go to a higher oil content AND richer mix settings both.

    a full topend for this engine is $100. no big deal, but i still wish it hadn't happened.

    thanks,
    steve
     
  13. DetonatorTuning

    DetonatorTuning Active Member

    Important Late Breaking News

    it's amazing how a small detail can suddenly put new light and perspective on things.

    if you were following my Staton 18.75 verticle thread oyu would have seen that i commented about changing to Amsoil saber at 75:1 and reporting good results.

    that was OVER 750 mls. ago during which time i wasn't taking it easy. at that time i had adjusted my carb and KNEW FOR SURE i was safe.

    THEN, i got my Staton gearbox and decided to modify my Dom. pipe to get mounting clearance. in the same thread i reported dramatic mid and high end increases. but i never thoght to rechack the carb settings or plug.

    i rode the bike that way under GEBE power for 40 mls. never being able to use more than 1/2 throttle at any speed or load without INSTANTLY endangering my LAST belt. then i took the GEBE off the bike and quit riding it while i was working out the gearbox layout and configuration.

    last night i rode the bike for the first time again, and knowing that i didn't need to worry abou tthe belt took it up into the highend.

    have you caught the drift of this yet ?

    the mods to the Dom. radically changed the characteristics of the pipe and drove the A/F/R LEAN in the upper half of the rpms. it took about 1.5 mls. to do the engine in.

    things look somewhat different now, don't they ?

    steve
     
  14. Skyliner70cc

    Skyliner70cc Active Member

    Thanks for clearing things up. I didn't think Amsoil sould be responsible for burning a hole in your piston.
     
  15. Zev0

    Zev0 Member

    VERY WELL DONE DT. :grin:
     
  16. grummy

    grummy Member

    DT, could you post some pics of your piston pls. Thanks buddy
     
  17. DetonatorTuning

    DetonatorTuning Active Member

    here ya go, enjoy
     

    Attached Files:

  18. arceeguy

    arceeguy Active Member

    Well, you do call yourself DetonatorTuning! :p
     
  19. DetonatorTuning

    DetonatorTuning Active Member

    yeah smarty, i knew that would be coming along soon !!

    it used to be cause i got things going, now maybe i better rethink the inference :shock:

    steve
     
  20. Wow ..Bummer.

    know how you feel .

    I installed a brand new Barnnet Race clutch in one of my shovel heads ( 94 inch Stroker).
    Took it for a ride and heard ,,,,,,,,,,

    Rapadie rap rap.

    tore the motor down and found out The Race clutch fell apart clogging my Return line and wasted a $4000 stroker motor for my Harley.

    I was NOT happy
    Hope all works out.

    cheers:smile:

    Bob



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