1. 2 Stroke Husqvarna Motorcycles Made In Austria - About 2014 & Newer
     TE = 2st Enduro & TC = 2st Cross

TE/TC Tiny Exhaust Port Purpose?

Discussion in '2st' started by AusCan, Nov 25, 2021.

  1. AusCan Husqvarna
    C Class

    Husqvarna Motorcycle:
    2016 te 300
    Other Motorcycles:
    Modified 1982 Suzuki gs1100 katana.
    I have a 2016 TE300, and have the cylinder off for a top end service. It's the 1st time I've had one of these engines apart, and I'm curious about the purpose of the tiny port above the main exhaust port? It isn't making sense to me... 20211125_141651.jpg
    AusCan, Nov 25, 2021
    #1

  2. ct cr430 Husqvarna
    AA Class

    Location:
    Connecticut , litchfield county
    Husqvarna Motorcycle:
    1981 cr 430
    Other Motorcycles:
    2007 honda crf450
    Compression release
    ct cr430, Nov 26, 2021
    #2

  3. AusCan Husqvarna
    C Class

    Husqvarna Motorcycle:
    2016 te 300
    Other Motorcycles:
    Modified 1982 Suzuki gs1100 katana.
    Why have a decompression port? I agree that it's what it's doing. I've only seen decompression valves on really old 2 stroke stuff, and not just a permanently open port.
    Seems odd to me to send un burnt fuel straight into the exhaust.
    Is it to change the rate of compression pressure rise?
    I'm really curious
    AusCan, Nov 26, 2021
    #3

  4. Dirtdame Administrator

    Location:
    Rock Springs Wy
    Husqvarna Motorcycle:
    11 WR300,13 WR125,18 FE501
    Other Motorcycles:
    17 Beta Xtrainer
    Think of it this way....the compression is lower until the rings pass that spot, so your question on that should answer itself. Maybe that was the least expensive, most efficient way to achieve the needed compression without retooling cylinder or piston configurations.:excuseme:
    Dirtdame, Nov 26, 2021
    #4

  5. Picklito Husqvarna
    Pro Class

    Location:
    Washington
    Husqvarna Motorcycle:
    430, 430, 430, ,400, 175
    Other Motorcycles:
    KTM250xc, KTM500mx, KTM440exc
    It's a time game. At kicking/E-start RPM that would produce a huge leak... and be an effective starting aid. At running RPM the piston passes that small hole so quickly that it's really a very small leak in the big picture.
    Picklito, Nov 26, 2021
    #5
    AusCan likes this.

  6. AusCan Husqvarna
    C Class

    Husqvarna Motorcycle:
    2016 te 300
    Other Motorcycles:
    Modified 1982 Suzuki gs1100 katana.
    ^^ Thanks, that makes sense.
    AusCan, Nov 26, 2021
    #6