Jetting '84 VF1000F carbs

Discussion in 'Mechanics Garage' started by TheYonks, Mar 29, 2012.

  1. TheYonks

    TheYonks New Member

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    Im about to pull my carbs tomorrow and rejet them. Havent had the pleasure of messing with the carbs on a VF before so itll be a learning experience. Was wondering if theres a good write up on it or if anyone has any helpful advice for a newbie. Im hoping to get it done by monday. I read that from the factory two of the main jets are 150s and the other two are 145s, which cylinder bank runs the larger main jets?. I have 160s and 165s to go in plus a set of 42 pilot jets, also going to throw in a K&N filter and maybe open up the airbox a bit.

    I also need to know what size chain and sprocket the VF1000F takes as mine need to be replaced soon.
     
  2. donald branscom

    donald branscom New Member

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    The main jet size can accomodate a wide range. They all work.
    The 49 state models came with 150's but some California ,models came with 112's!!

    I do no know why you would want to use main jets as large as 165's.

    What really needs attention is the midrange especially if you do not have the stock airbox.
    That is another discussion.

    If you have the stock airbox then I would just stick with standard needles and the 150 mains would be more than enough even with perfomance exhausts as long and the airbox is stock.

    Adjust your mixture screws properly so it does not backfire.

    The #42 pilot jets should be perfect. I would not go larger.
     
  3. GreyVF750F

    GreyVF750F Member

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    Last edited: Mar 30, 2012
  4. TheYonks

    TheYonks New Member

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    If I open up the airbox would it be better to run the needles and springs from a dynojet kit instead of shimming stock ones? (I have a DJ kit laying around that I decided not to install because I don't like the idea of drilling the slides)



    Thanks for the info, should prove to be helpful.
     
  5. donald branscom

    donald branscom New Member

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    Is this Dynojet just for your year of carbs?
    What year is the bike?
    Drilling the hole larger just makes the slide drop down quicker. Thats all.
    Makes a crisp clean cut off. But the reason I would not use it on YOUR bike and that engine, is because two carbs are down draft, and two are side draft. Won't work, don't drill them!!

    I used a drill on my Kawasaki 1500 downdraft single carb and it was a immediate improvement.
    On that same bike the needle supplied would not work at all, and Someone at Dynojet even said the Cobra kit was better. The stock needle worked best.
    Those reports of the Dynojet kit needle not working on the 1500 was echoed by the other members of the Kawasaki forum.
     
  6. donald branscom

    donald branscom New Member

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    Are the 1984 slide needles adjustable? (don't think so)- Otherwise do they have notches on the needles with a circlip?
    If not... I would leave them alone with a stock air box.
    If you do not use the stock air box I would add shims to all of the slide needles. Add two shims/washers equal to .039 thousandths or 1mm. Free breathing intakes.
     
  7. TheYonks

    TheYonks New Member

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    the dynojet kit I have is for '84-'86 VF1000Fs,Rs, and Sabres. It comes with 3 sets of main jets depending on which specific model bike you have. For the VF1000F they want you to use the DJ150 main jets in the kit, I'm wondering how large they are since the numbers dynojet puts on their jets are not comparable to the OEM equivalent. If it turns out their jets are smaller than the 160s/165s I picked up I'll try running them. I already ran out and got some washers that will work for shimming which is as far as I know the only way to 'adjust' the needles.
     
  8. donald branscom

    donald branscom New Member

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    Are the shims brass washers?
    Make sure to measure them with calipers. (thickness)
    Make sure they are all the same measurement.
    Also if they are brass washers/shims make sure the backside is smooth sand them on the back with a finger nail file or a metal working file to remove the burr.
    When they are punched out it leaves a burr.


    How thick are the shims???

    Can you show or tell me what you have for the air box exactly?

    BTW the carbs on the sabres and the VF1000R/andF are the same. The clutch pressure plate is the same exactly.
    Later on you may appreciate that info.
     
  9. GreyVF750F

    GreyVF750F Member

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    Correct on the washers. I bought some at a local hardware store. They are about the same size as the needle head and are .020" thick. I could only get to under each needle cap. Which was to rich, went back to one. You might also be able to find some around .010" for fine tuning. Don't know what you have now.
     
  10. donald branscom

    donald branscom New Member

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    You can get that second .020 shim on by just carving the little plastic thing with a #11 Exato knife.

    With almost no air restriction on that engine it needs two shims under the needle.
    Of course the type of mufflers is part of the equation.
     
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