Broken Engine Stud & Repair

Discussion in 'Motorized Bicycle General Discussion' started by MelMartinez, Jul 5, 2009.

  1. MelMartinez

    MelMartinez Dealer in Mexico

    Joined:
    May 24, 2009
    Messages:
    52
    Likes Received:
    0
    I had an stud loose because the thread was broken in the front of the engine.

    Maybe it was too tight or because I was riding at full speed for a long run and had too much vibration.

    Anyways, the engine was loose and I had to make a quick repair at home.

    First I removed with a saw and file all metal until I had a flat surface, then drilled a 3/16" hole and a 1/4" tap.

    I made an square angle support and two 1/4" holes for new screws and it´s back in the road.

    Today I made a testing ride at full speed, both in flat street and uphill, and it´s working just fine. I hope this repair may last some miles ahead.

    BTW, my MB is not easy to ride with this LowRider front fork; it has a very poor handling. In below picture you can see two more MB projects I have for later this month.

    See You in the Road !!!

    dance1
     

    Attached Files:

  2. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

    Joined:
    Mar 20, 2008
    Messages:
    6,170
    Likes Received:
    18
    Two bits of advice I can give you;

    First... Get rid of those rubber engines mounts. They will allow the engine to move and cause problems (like broken studs)
    Second... When you use one of those lowrider forks, you have to also use shorter cranks so that the pedals don't hit the ground when you turn!
    Cranks from a Schwinn StingRay will work.
     
  3. MelMartinez

    MelMartinez Dealer in Mexico

    Joined:
    May 24, 2009
    Messages:
    52
    Likes Received:
    0
    Thanks for the advice Venice;

    Actually I don´t like these forks and I´m going to change them... as soon as I make them, which will take a few weeks from now.

    And you´re right, I´m hitting everything on ground with those pedals and the muffler tip, lol.

    See You in the Road !!!
     
  4. 2door

    2door Moderator
    Staff Member

    Joined:
    Sep 15, 2008
    Messages:
    16,301
    Likes Received:
    26
    Mel,
    I've never seen that approach to a brocken stud before but it might be just fine. A very interesting concept. As they say, "any port in the storm". Good luck and let us know how that repair works for you after a few miles. Also, Venice Boy gives good advice. Bolting the engine solid, without the rubber is a better way to go. Vibrations are then transfered into the bike frame and not concentrated on the mount and studs.
    Tom
     
  5. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

    Joined:
    Mar 20, 2008
    Messages:
    6,170
    Likes Received:
    18

    Ya... I just finished building this bike a few days ago, The pipe scraped on the ground a few times, so I cut the stinger off!
    It has StingRay cranks on it.
    [​IMG]
     
  6. MelMartinez

    MelMartinez Dealer in Mexico

    Joined:
    May 24, 2009
    Messages:
    52
    Likes Received:
    0
    Actually I use rubber to protect the paint in the frame. But I´m going to follow your advise and will remove it.

    Also I have to work in my "Beer Icepack Support" box I have behind the seat. I have to level it and move it further to the rear.
     
  7. MelMartinez

    MelMartinez Dealer in Mexico

    Joined:
    May 24, 2009
    Messages:
    52
    Likes Received:
    0
    Nice bike you have above, Venice. It looks a clean installation.

    If I change for shorter pedals I´d have to change for a bigger rear sprocket also. I´d rather change the instable front suspension fork to improve handling.
     
  8. MelMartinez

    MelMartinez Dealer in Mexico

    Joined:
    May 24, 2009
    Messages:
    52
    Likes Received:
    0
    Re: Engine Stud Repair & New Fork

    I´ve got this brand new suspension front frork and i´m going to change it for the Low Raider fork.

    It was not available in black color, thus I´ll have to sand it and paint it black to match the bike.

    I need another three days weekend !!!

    See You in the Road !!!
     

    Attached Files:

  9. RPM

    RPM New Member

    Joined:
    Jun 7, 2009
    Messages:
    37
    Likes Received:
    0
    Hey Mel,

    I'll keep your repair in mind, it looks like it will work. As far as your rubber motor mount I'm a firm believer in a damper system on my MB. Its the reverberation I don't want cycled back into the engine and want dissipated as quickly as possible. Sure it goes down into the frame but its the metal to metal is whats bad. If it was detrimental to car engines they wouldn't have motor mounts cast in rubber.

    To make my point I burn firewood in my woodstove, I use an eight pound maul with a wood handle to split the wood. Someone once gave me an eight pound maul with a 3/4" pipe welded on the end because they were always overstriking the wood when splitting it thus breaking the handle. After using it for fifteen minutes I gave it back to them.
    The shock with this handle on it was tremendous and more than I could bear. It all came back to me. The difference with the wood handle and metal was night and day. The shock with the wood handle went right into it and died there.

    It all depends on what your using and how much of it and how well its anchored. Looks like ya got an awful big chunk of it there, I'd be leary with that much. I don't actually use rubber but if I did it would be something such as the material used to mate the sprocket to wheel that comes with these MB engine kits but much thinner.

    What I use is an old plastic dish rack drain. The ones you put your dish rack on in the kitchen sink to catch the water while the dishes dry. The one I have is actually about 3/16 " thick is kinda rubbery but doesn't squish down like soft rubber would. If you could find some thin hard rubber that would probably do it. I also like the stuff I use because it takes up the void where there is no contact between the frame and mount.

    Was the front fork on your ride an "add on" feature or did it come that way?

    RPM
     
  10. Sydneysider

    Sydneysider New Member

    Joined:
    Mar 20, 2009
    Messages:
    189
    Likes Received:
    0
    did exactly the same thing at the same spot on my bike and it didnt give me any probs.. I was even popping wheelies on it .wee. I rode the thing for another 4000 miles before it needed new rings. Should be ok..
     
  11. MelMartinez

    MelMartinez Dealer in Mexico

    Joined:
    May 24, 2009
    Messages:
    52
    Likes Received:
    0
    The LowRider front suspension fork is an add on to my Micargi Cruiser. Actually the original front fork is like the one in my avatar.

    I changed the front fork to have a suspension, but the LowRider fork has a very poor handling, and it´s even dangerous to ride the bike above 15 mph. It´s very instable.

    Now I have a much better front fork and I´ll change it after painting. I´m sure it will improve performance and handling at high speed.

    See You in the Road !!!
     

Share This Page