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

XC 500 compression

Discussion in 'Vintage/Left Kickers' started by greenstreak, Mar 12, 2010.

  1. greenstreak Husqvarna
    C Class

    Location:
    Tucson AZ
    I just got a 1985 XC 500 and did a compression test on it. I can not find a range where it should fall in. Anyone have a clue to where I can find a reference to check it against? Compression on my cylinder is 127 PSI.
    greenstreak, Mar 12, 2010
    #1

  2. 1983XC175 Husqvarna
    AA Class

    Location:
    Maryland
    sounds low
    1983XC175, Mar 13, 2010
    #2

  3. ruwfo Administrator

    Location:
    NJ
    Husqvarna Motorcycle:
    1980 390CR, 1982 430CR, 1984 400WR
    Other Motorcycles:
    1985 250XC, 2016 FJ-09
    Did you do the compression test with some oil in the cylinder?

    127psi is on the low side, should be 150, but remember the later 500's
    had lower compression ratio then the even the 430 .

    Here's a article on how to do compression tests & good ref repair site

    http://www.dansmc.com/compression_test.htm


    Husky John
    ruwfo, Mar 13, 2010
    #3

  4. Husq.fleet Husqvarna
    AA Class

    Location:
    Pendleton Oregon
    Good link John, maybe they can pin that to the tech section. I always pull the slide out when checking comp. That way I dont have to hold it wide open. 125psi with a 500 @ 9.5-1comp might not be too bad. I freshen up my 250's @ 125psi but they have 12-1 compression, freshened up 180-160 psi. Another factor is the kicking speed which is going to be slower on the big bores. Higher cylinder pressures also help ring seal by forcing ring to the cylinder wall. Have you pulled the pipe and carb/reeds to look at cylinder?
    Husq.fleet, Mar 13, 2010
    #4

  5. greenstreak Husqvarna
    C Class

    Location:
    Tucson AZ
    I did a proper compression test with throttle wide open and kicked hard 10 times. All my references I have are for Japanese engines, and their 2 stroke singles.
    Does anyone know how or where I can get an official reference? I have a Husqvarna CD that I got off of E Bay, but it does not list the compression range.
    If I need a set of rings, where is a good place to buy them? The guy I got the bike from thinks it is a factory piston and not a Wiseco.
    greenstreak, Mar 14, 2010
    #5