YZ......465 vs 490

Discussion in '2 smokers' started by 2stroke1971, Nov 23, 2020.

  1. 2stroke1971

    2stroke1971 Adventurer

    Joined:
    May 21, 2014
    Oddometer:
    17
    Location:
    East Coast
    Ive got an 81 465 and a bucket of spares.

    I acquired a free 490 bottom end last year, not even on purpose....its really nice. As soon as my lazy ass manages, Im going to dig the 465 spares out and see if some of it looks like it will interchange.

    The motors have the same stroke....anyone know if a 465 top end will work on a 490 bottom?
    As in drop it on and go? Cuz I have a spare 465 top end.
    At that point...what on earth would I do with another 50 hp 2 stroke engine? Havent a clue...but my mind is coming up with all kinds of stupid ideas that would be cool but will never actually happen because $$$$ and all the other hungry mouths in my shop full of junk.

    Find an old quad chasis....an old streetbike frame...utter dumbness........
    #1
  2. assquatch20

    assquatch20 Long timer

    Joined:
    Jan 31, 2010
    Oddometer:
    1,449
    Location:
    Tennessee
    I'm reading some related stuff right now and I think the cases will swap but the gears are helical on the 465 and straight on the later 490/500 bikes. The kicker shaft is different, not sure what else... should be possible but not sure what issues you'll run into.
    #2
  3. jimroid

    jimroid Long timer

    Joined:
    May 14, 2013
    Oddometer:
    1,464
    Location:
    Pisgah Forest,N.C./USA
    I think 465 piston and rings are pretty much impossible to find versus much more available 490 parts. Something to consider.
    #3
  4. 2stroke1971

    2stroke1971 Adventurer

    Joined:
    May 21, 2014
    Oddometer:
    17
    Location:
    East Coast
    Well...the 465 jug drops right on the 490 bottom end. the 490 stuff I have is from an '83
    Looking at the heads from the 465 and 490, they look identical as far as combustion chamber, though if I actually run this with the 465 jug Id use the 465 head.
    Pistons are dime a dozen for the 465 on Ebay. Id have to get a clutch basket, or else explore swapping out the crank gear on the 490 to a helical one....though 465 baskets are as hard to come by as the 490 units. They lived a tough life in there.
    Oh yeah, the 490 reed cage dropped right into the 465 jug. I even have the complete ignition for the 490.
    Ive got to dig my bin of 465 spares out of the shed and see what else might work.....but it appears for a piston and clutch basket Id have a complete motor. Who knows. maybe if I run out of projects. or if I can score a ratty 490 bike with a blown up engine or something like that. For all I know the basket from this very engine is in my bin---they came from the same person although years apart, the 490 stuff coming to me with some other stuff after his passing unfortunately. I remember them saying they were going to use a 490 basket for the 465 that I have except for that helical vs straight cut gear issue.
    He'd have a good laugh if he could see me use this 490 stuff. Ride on Brother!!!!!
    #4
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