Cold weather jetting

Discussion in 'Engine' started by Tommyb6273, Nov 20, 2020.

  1. Tommyb6273

    Tommyb6273 New Member

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    Any recommendations for a starting point on cold weather jetting?

    My son wants to ride his 88 blaster this winter. We live in michigan.
     
  2. Awk08

    Awk08 Administrator Staff Member Technician

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    My original blaster I bought new in 1996 came with a stock 230 main and an extra 240 it said to install in temps under freezing
    I either never changed it or did the first year and never changed it back ? and rode in the winter many times, under freezing ? I'd think so.
    I assume the 230 main was good at sea level, which requires richer jetting than here at 1800' elevation, so was the 230 main rich the whole time here ?
    it ripped (for stock) I had it for 8 years and never fouled a plug or rebuilt it, sold it still starting on 1-2 kicks, even in the cold.

    What we've learned on here .... the stock blaster with no mods and the oil injection will take a beating and keep going
    once we start modding them .... pipes/filters/engine mods, etc. .... they become much more sensitive to jetting changes to prevent damage
    but they are so "de-tuned" in bone stock form, it takes alot to damage them.

    We've never compiled solid numbers on temp jetting, as every bike and elevation is different
    Bone stock ? .... throw a 240 in it for temps under 40 and see how it does ? maybe up another size for every 20 degrees lower ?
    give at all it can take without fouling plugs or running poorly at full throttle

    the airscrew should be tuned for highest idle, I'd think a 1/2 turn in for easy starting and good idle in colder temps ?
    I've never changed the clip position or needle on a stock blaster carb, for any reason.

    I've been going 3 sizes up from a 155 for summer to a 162 in winter on my modded/Keihin carb blaster and doing well
    under freezing I stay riding the couch nowadays :D
     
  3. Tommyb6273

    Tommyb6273 New Member

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    Very helpful, appreciate it.








     
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