Has anyone had an engine that wants to tilt?

Discussion in 'General Questions' started by ChrisHill, Sep 3, 2007.

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  1. ChrisHill

    ChrisHill Guest

    Can anyone shed some light on this for me...please?
    This is the first time I've run into this. It's on a bike that I built a couple of days ago :(
    I've done everything that a semi knowledgable person can do as far as remounting, and being 100% certain that everything is proper. (I've built more than 30 bikes so far, and this is the first time I've had this problem.)
    And even after doing all of that...again yesterday, I took it for a boot...cruised around 60 km/h for about 5 minutes, and again the engine started to lean over to the left.
    It's the jug that is tipping to the left, almost as if the engine were rotating in the bike's frame.
    Is there anyone else that has had this problem before and what is a corrective action to use?
    I would hate to spoil a great looking bike with a headstay, but that is the only thing left in my mind to keep it sitting upright.
    I am not at home this weekend so I have no way of taking any pictures of this tilting engine. I will try to send a pic probably later today or tomorrow.
    Any, and all advice is appreciated.
    Thank you

  2. ironwarlock

    ironwarlock Guest

    Sounds like the motor is not bolted tight and is turning with the torque.
  3. gone_fishin

    gone_fishin Guest

    if you're completely stumped and this is an unusual situation, why not it take off and closely inspect the holes for the proper angle (i suppose the whole block could have been off during the drilling process)...or the frame size could be just a tad too small?
  4. azbill

    azbill Active Member

    do you have another motor mount spacer you can try?
    sounds like it's not sitting right in relation to frame
    hopefully, that's all it'll be
  5. Take a beer can,cut it up and wrap some around the frame where the mounts go.
  6. ironwarlock

    ironwarlock Guest

    Drink the beer first. ;)
  7. OldPete

    OldPete Guest

    I have never installed one of these engines but will offer my $0.02.

    If all else is OK, there just might be a sympathetic vibration between this engine and frame causing the motor to move. Try cleaning the frame n' motor mounts and install with a coating of adhesive silicone in the area of frame contact. Give it 36 hours to completely set-up.
  8. ChrisHill

    ChrisHill Guest

    Thanks, but I have done the remount thing like 4 times now

    Thanks to everyone for the quick responses.
    I have un-mounted, checked, and remounted everything 4 times over now. This is why it is so baffling to me. I can understand if a stud was not mounted proper and squared, or if the rear mount spacer block was not honed, and angled correctly (I contour it to better fit with the seat post tube), but none of these things appear to be an issue...everything looks great to my naked eyes, lol.
    I'm actually starting to think (as I'm writing this) that I will leave it alone until I get back home, and try a different mount spacer in there. I guess it is possible that maybe I messed up the angle or something when I honed it down...looks ok with the eye though.
    I'll still upload the pic later when I get home, and will definately be sure to write and let everyone know if a different spacer block solves the problem.
    Thanks again everyone, the help is appreciated.
  9. srdavo

    srdavo Active Member

    is your engine tilting to the left under torque? then does it right itself when you let off the throttle?
  10. 5-7HEAVEN

    5-7HEAVEN Guest

    :confused:what system do you have? friction drive? gear chain drive? GEBE belt drive?
    is the engine on left or right side of bicycle wheel?
  11. ChrisHill

    ChrisHill Guest

    This is a 80cc chinese happy time, lol.

    Guess I should've mentioned what engine I have on this, eh?
    I think I have it figured out...the way that I did the front mount was not tight enough. I found this out as I loosened it a little more and it swiveled easier, lol.
    Tightened it back up, then over tightened just to the point of starting to crush the downtube, and everything seemed to be ok for the 15 minute ride home tonight at WOT.
    Seems to have a bit more punch to it as well now that it is mounted better.
    I raced my cousin back to my place. He was in his huge, gas guzzling SUV and doing the 60 km/h speed limit, and I was on my bike...managed to get the bike up to the house just as he was pulling into the parking lot. He was amazed, lol. That was the first time he had seen one of these go and now he wants a bike built for him too.
    No rest for the wicked tonight, lol.
    Thanks for eveyone's input to helping me get this problem fixed. It is very appreciated.
    Oh, and pictures will have to wait until after work tomorrow, it's pretty much dark out there now.
    Good night all.