Mounting 2 stroke on an 18" frame

Discussion in 'Frame Mounted Engines' started by John62, Apr 8, 2008.

  1. John62

    John62 New Member

    Has anyone ever tried mounting a 50 or 70 cc motor on an 18" frame? I have an older Raleigh M50 mountain bike and was thinking of motorizing it. I emailed Dax but he said he didn't know if it would work and I hate spend the money if it won't fit. Any suggestions?

  2. Ghost0

    Ghost0 Guest

    Mine is a 17" and it fits, barely

    Attached Files:

  3. John62

    John62 New Member

    Thanks Ghost, that picture of your 17" bike gives me confidence I can make it fit on my bike.
  4. Your front tube is a factor here. You may get by drilling that hole but my Diamondback was a tight fit as well and using that adapter where you drill that hole would have not given me enough space for the carburetor.
    So I took a sledge hammer to squeeze the tube a bit then a grinder to get the bolts to clear so it would mount the way it was meant to go thereby giving me the carburetor clearance I needed. I'm not suggesting you do the same but it worked for me.

    View attachment 1453

    Here's a good pic from my picture gallery thread of my front mount and how I needed to do it this way or I wouldn't have carb clearance.
  5. John62

    John62 New Member

    Thanks LP
    I'm pretty handy with a large hammer (was a tool & die guy in a previous life) so I'm sure I can do what it takes to make it fit. I just didn't want to have to do any major cutting and welding. What size is that frame of yours?

    If at first you don't succeed get a bigger hammer!
  6. I never measured it but I'm sure the dimensions are similar to Ghost0's.
    That front tube is just slightly too thick so it didn't need much squeezing.
    Is your frame steel? I'd be careful with hammering if it's aluminum.
  7. John62

    John62 New Member

    My frame is steel and not as thick as a Diamond back and since its an 18" it should fit. I read somewhere that if you take two flat sticks 11" each and join them in the center to make an X you can use it to see if you have enough room. If you can fit them in the space between the bars the motor will fit. I have just enough room using this trick, I'll let you know if this works.