Crankshaft end float

Discussion in '2-Stroke Engines' started by Biker, Jun 22, 2010.

  1. Biker

    Biker New Member

    Well i've just come in from servicing my Gen 1 48cc motor.It has about 2 tankfuls of fuel thru it.I noticed the small gear stuck out about 1/8" from the clutch gear and when i pushed on it it simply moved over,near on the full 1/8' inch.Surely to much uh!Is this likely to cause any probs or should i just ignore and keep riding?

  2. srdavo

    srdavo Active Member

    Was the bolt in the center of the gear tight?
  3. Biker

    Biker New Member

    Yes it was tight.I've done some searches here and over at the other board and haven't been able to come up with anything,in as much as what it's supposed to be,it seems it's there in some motors and not others.Can't do the conrod much good tho as it has to move over inside the piston.I'm thinking the crank will move to one side under load then be forced over to the other side when the throttle is released because of the bevel gears on the primary drive.And the shaft has to be loose in the crank bearings.
    I guess i've got myself a generic then.No name on the box it came in.Would be interesting if the name brands came with a specified figure for crank end float,I've rebuilt my share of old motorbke engines and they are usually .004" or something but this is like 70 or 100 thou!!
  4. GearNut

    GearNut Active Member

    These engines are "A bunch of parts flying about in close formation" as my old boss would say.
  5. Biker

    Biker New Member

    Sounds about right:rolleyes7:A couple of shims either side of the crank would have sorted things.No way are these engines going to last long if this is the case,if it fails early I'll just go to a motorbike then,no use putting up with something that's uneconomical in the longer run,i wouldn't be confident that the brand name engines are any different after reading these pages back to 2006.Seems the needle bearing engines are the same,i've seen pictures of the needle near on half way out of the rod,Piston boss not machined properly!i don't think i'd see anything this sloppy on any chainsaw motor.Thanks for the replies.