Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: Gs450, suggested jets?

  1. #1
    Join Date
    Sep 2019
    Location
    OC, California
    Posts
    107

    Default Gs450, suggested jets?

    Hey guys (and gals),
    I've got my bike working pretty much perfectly. It's a stock setup, using the oem airbox, bs34ss carbs, etc. I've changed the gearing though, to reduce RPMs at the highway speeds I drive at.

    I'd like to get a bit more power out of her, she's got 115 main jets right now. I'm following the FactoryPro guide, unless anyone has better suggestions.
    I'm trying to avoid buying excess jets I may not need, so would anyone have any suggestions on a good size or two to jump up to?

    Thanks everyone.
    1982 GS 450L aka Lil' Red
    1980 GS 1000G aka Big Red (Resto-mod WIP)

  2. #2
    Join Date
    Jun 2012
    Location
    On the edge.
    Posts
    343

    Default

    Unless you are having problems related to poor jetting, changing jets will not increase power.

    The best thing you can do to increase power is to change your gearing back, so you are back into the power band.
    Those engines DEPEND on spinning happily at higher revs.

    That said, ... because of the ethanol in today's fuel and the fact that the carbs were set lean by the factory, going to a 117.5 main jet, shimming the needle just a bit and turning the pilot screws out about 1/2 turn won't hurt a bit.
    If you're not living on the edge, you're taking up too much space.

  3. #3
    Join Date
    Sep 2019
    Location
    OC, California
    Posts
    107

    Default

    Alright Who Dat?, I ordered 117.5 and 120 main jets just to see how far I can get it. I've previously adjusted the pilot screws using a single colortune, that helped quite a bit though I'm still a noob at getting into the minutae of the carbs.

    Re: the RPMs, I'm sure I need a bigger bike, but for now I wanted to reduce the RPMs at 85mph, as seems to be the going speed in SoCal.
    1982 GS 450L aka Lil' Red
    1980 GS 1000G aka Big Red (Resto-mod WIP)

  4. #4
    Join Date
    Dec 2014
    Location
    In the doghouse, usually.
    Posts
    619

    Default

    I'm surprised the 450 will even get to 85, let alone stay there.

    It has been a while since I have been out there, I did not realize that the speeds on the surface streets had gotten that high. I can only imagine what it's like on the freeways.

  5. #5
    Join Date
    Sep 2019
    Location
    OC, California
    Posts
    107

    Default

    Quote Originally Posted by phydeauxmutt View Post
    I'm surprised the 450 will even get to 85, let alone stay there.

    It has been a while since I have been out there, I did not realize that the speeds on the surface streets had gotten that high. I can only imagine what it's like on the freeways.
    Oh, really? It's possible I get my bike just past 102mph per a GPS speedo and my phone every now and again. But I might be theoretical, just to avoid any legal issues. The 450s have quite a bit of juice to them, just need a little more. Famous last words.
    1982 GS 450L aka Lil' Red
    1980 GS 1000G aka Big Red (Resto-mod WIP)

  6. #6
    Join Date
    Sep 2012
    Location
    Ireland
    Posts
    4,595

    Default

    It's the 250 that will barely get to 85mph, not the 450.
    ---- Dave
    79 GS850N - Might be a trike soon.
    80 GS850T Single HIF38 S.U. SH775, Tow bar, Pantera II. Gnarly workhorse & daily driver.
    79 XS650SE - Pragmatic Ratter - goes better than a manky old twin should.
    92 XJ900F - Fairly Stock, for now.

    Only a dog knows why a motorcyclist sticks his head out of a car window

  7. #7
    Join Date
    May 2017
    Location
    ohio
    Posts
    251

    Default

    You don't need a bigger bike, you already have one. Get that 1000G up and running and you'll have all the power you can use safely on the street.
    Expecting the Spanish Inquisition
    1981 GS850G: the Ratzuki
    1981 GS1100E

  8. #8
    Gorminrider is offline Forum Sage Past Site Supporter
    Super Site Supporter
    Join Date
    Aug 2012
    Location
    British Columbia, Canada
    Posts
    4,628

    Default

    ...I've changed the gearing though, to reduce RPMs at the highway speeds I drive at.
    ...and thereby reduced your "power". Better to rev high. Max power from the engine is somewhere around 7500 rpm . You can't get blood from a stone and it's not a Harley.

  9. #9
    Join Date
    Sep 2019
    Location
    OC, California
    Posts
    107

    Default

    Quote Originally Posted by Gorminrider View Post
    ...and thereby reduced your "power". Better to rev high. Max power from the engine is somewhere around 7500 rpm . You can't get blood from a stone and it's not a Harley.
    Don't worry Gorminrider, I made that choice consciously. There's a small feeling of resonance at speeds I tend to ride at, reducing the RPMs a little has helped tremendously. I don't really care about launching off the line at top speed.

    Thanks again Who Dat for the advice on the jets, I'll be giving them a shot; you'll all be the first to know of success (or problems).
    1982 GS 450L aka Lil' Red
    1980 GS 1000G aka Big Red (Resto-mod WIP)

  10. #10
    Join Date
    Sep 2019
    Location
    OC, California
    Posts
    107

    Default

    Happy thanksgiving everyone. I've just cleaned and reassembled my carbs. Should I balance and adjust idle, air mixture, etc first with original jets, or do all that after installing new jets?
    1982 GS 450L aka Lil' Red
    1980 GS 1000G aka Big Red (Resto-mod WIP)

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •