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

1986 WR400 engine swap to a 510 4 stroke

Discussion in 'Vintage Restoration Projects' started by 1986WR400, Jan 20, 2010.

  1. 1986WR400 Husqvarna
    B Class

    Location:
    San Diego, CA
    Does anyone know if the 510 can be swapped into the 1986 WR400 frame? I've looked at the 510 and it sure looks like it would bolt right up with the exception of dimpling the front down tube for the twin exhaust and swapping out the air box plastic, tank plastic and seat.
    1986WR400, Jan 20, 2010
    #1

  2. Michel Dufayard Husqvarna
    Pro Class

    Location:
    France
    It works with a 84 wrlc frame, so I think it could be possible with a 86 2stroke frame.
    Look at the front frame if a 84 looks like a 86 frame.

    Attached Files:

    Michel Dufayard, Jan 21, 2010
    #2

  3. ruwfo Administrator

    Location:
    NJ
    Husqvarna Motorcycle:
    1980 390CR, 1982 430CR, 1984 400WR
    Other Motorcycles:
    1985 250XC, 2016 FJ-09
    Looks pretty close

    Michel,
    Yes it sure looks like it would fit, here's a few pictures of my old
    86 400wr.
    Here's my thoughts
    1) you may have to make new motor mounts, the 510 motor mounts
    are different then 2 stroke ones.
    2) I don't think you need to worry about the flat on the frame
    for pipe clearance. Mine fit in a 81 250CR frame .
    3) I doubt the 510 original air box will fit on the 400wr frame without
    making some new brackets.
    4) There's a 86 510 frame on Ebay though? which may just make
    you life easier

    I'm still working on my 86 510 project, almost at the point where i'm
    going to she if she runs this weekend :)

    Husky John

    Attached Files:

    ruwfo, Jan 21, 2010
    #3

  4. Michel Dufayard Husqvarna
    Pro Class

    Location:
    France
    Yes you need to put 2 stroke motor mounts in your 2 stroke frame for your 510 motor.
    I think it is OK like that !
    Michel Dufayard, Jan 21, 2010
    #4

  5. 1986WR400 Husqvarna
    B Class

    Location:
    San Diego, CA
    Thank you gentlemen for your timely response. I love my old reliable 400 engine, but I've always been a 4 stroke rider and I'm ready to get back to thumping. gentlemen, have a great day!
    1986WR400, Jan 25, 2010
    #5

  6. fran...k. Husqvarna
    AA Class

    Location:
    eastern ct
    Husqvarna Motorcycle:
    420ae 98wr125 2004wr250 others
    Other Motorcycles:
    electric freeride 1993 yam gts
    I think you will find the four stroke radiators are longer. Are you sure the exhaust pipes won't end up interfering with the branching twin down tubes which straddle the two stroke pipe?

    Fran
    fran...k., Jan 25, 2010
    #6

  7. Hwy Mini-Sponsor

    Location:
    SF Bay Area
    Husqvarna Motorcycle:
    '86 510TX / '90 250WXE / '87 510TE
    Other Motorcycles:
    '04 KTM 525MXC / '91 KTM 300DXC
    Is it air or water cooled 510?
    You may have problems with the pipes and frame clearance. Here is a reference photo of the pipes.

    [IMG]
    Hwy, Feb 11, 2010
    #7