1. Husqvarna Motorcycles Made In Sweden - About 1988 and older

390 piston pin - Spacers not thrust washers ?

Discussion in 'Vintage/Left Kickers' started by GaryM, May 17, 2017.

  1. GaryM Husqvarna
    AA Class

    Location:
    Austin, Tx
    Husqvarna Motorcycle:
    1981 430cr second 430 CR 500cr
    Other Motorcycles:
    1981 490 Maico
    I am rebuilding an 8O 390 CR engine. Confused by Husky as this piston uses not thrust washers
    on piston pin but spacers They are Aluminum and slide inside the rod bearing bore.
    Yes they fill area and space but?

    But why not use the wider bearing from the 430 and not use spacers?

    Thought I would replace them, but seems ok. Had a wear mark on one side I removed They don't seem to be available anywhere. Have to make some I guess for future.

    Any comments?
  2. grouty Auto Lover ...

    Location:
    South West UK
    Husqvarna Motorcycle:
    78 390WR, 78 390 AMX, 500 Humph
    Other Motorcycles:
    works 73 CCM 520, another 73 CCM520
    Picture !
    What make is the new piston ?
  3. jimspac Husqvarna
    Pro Class

    Location:
    Connecticut
    Husqvarna Motorcycle:
    82 250WR, 82 430WR, 84 250WR, 85 400
    Other Motorcycles:
    86 400WR, 82 Montesa Cota 349
    The thing to remember is that the rod is piston centered and allowed to float on the big end of the connecting rod. The spacers position the small end central within the piston. The piston will then center the rod within the crank. The rod should not float at the small end, but at the big end.
    DaveM likes this.
  4. oldbikedude Husqvarna
    Pro Class

    Location:
    Honey Brook Pa.
    Husqvarna Motorcycle:
    1988 wr 430 with cr suspension
    Other Motorcycles:
    66flh,67 CA77,76 CR125M,73H1,74ty250
  5. GaryM Husqvarna
    AA Class

    Location:
    Austin, Tx
    Husqvarna Motorcycle:
    1981 430cr second 430 CR 500cr
    Other Motorcycles:
    1981 490 Maico