Stuck jet block in carbie.

Discussion in 'Frequently Asked Questions' started by kevman, Oct 6, 2018.

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  1. Oct 6, 2018 #1

    kevman

    kevman

    kevman

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    Ok I had dramas with the carbs..so I pulled them off the bike and started dismantling them.I have reached the point of removing the jet block and it seems stuck.I tried levering it off with a large screwdriver but it doesn't want to budge.Any ideas on how to remove them would be great.Thanks Kevman.
     
  2. Oct 6, 2018 #2

    maleko89

    maleko89

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    Did you remove the two phillips screws and the brass needle jet screw up top?


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  3. Oct 6, 2018 #3

    Fire-medic

    Fire-medic

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    This is the screw to remove, the big brass one, then the jet block should pop-off, assuming you also removed the two phillips screws holding it. Be sure you don't lose the brass flat washer in the jet block, sometimes it's stuck in there and you use a small blade screwdriver to pop it out. The brass flat washer is immediately-under the brass slotted screw. See below for more info on removing this brass flat washer.

    Sometimes the jet block gasket is stuck on the piece, and you have to tap the jet block to break the seal. Before you do that, remove the CV diaphragm/slide, by removing the CV cap sticking-out the side of the exterior side of the carbs. Be sure you do not lose the small o-ring at the bottom of the CV cap seat, on the carb body.

    I suggest using a properly-sized punch to lightly force out the carb needle valve seat. The needle valve seat will come-out once the CV cap has been removed, and then the diaphragm/slide. Place the punch on-top of the needle valve seat from the float bowl side, but be sure you remove the flat washer under the large brass slot head screw. If light tapping on the needle valve seat doesn't force it out, spray some carb cleaner into the seat area from both the top and the bottom as the carb body is held, so the needle valve is positioned vertically (installed on the bike, the carb body would be horizontal, but you want to position the carb body so the solvent will flow downwards to remove the gummy gas residue holding onto the needle valve body). You may have some gummy residue holding it in-place. Wait for the solvent to bust it loose, and then re-try tapping on the needle valve seat from the float bowl side. You should NOT need to use a hammer on the punch, pressing against the needle valve seat. Just tapping on the top of the needle valve seat with the weight of the punch from the carb float side should force it out into the carb mouth area, and it should fall-out the diaphram/slide passageway.

    There is also a thin o-ring on the needle valve body between the jet block and the carb body. Do not lose this! It's easy to overlook, and when you remove the needle valve body, the o-ring will probably be stuck inside the jet block gasket. It's easy to overlook, so remove it and place it safely-away, awaiting the reassembly.

    The float is also set to the top of the casting mark circle, a good starting point for a static set of the float level. The bottom of the float just touches the top of the casting mark circle.

    I just spent this morning finishing a cleaning of a set of CA carbs, which have a circuit for the evaporative emissions canister that the CA bikes have that the 49-state carbs don't. I have some pics to post about the reassembly that may help someone.

    If you tear-down the carbs this-far, you might as-well replace the float valves, they aren't expensive, and you will probably get many years out of a replacement. You can buy a rebuild kit or you can get the float valves separately. My local shop sells me the rubber-tipped float valves, they are K&L aftermarket.

    A good disassembly, cleaning in an ultrasonic tank, and reassembly usually just requires a jet block gasket and a float needle, I've found.
     

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  4. Oct 6, 2018 #4

    kevman

    kevman

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    Thanks for the replies and the correct answers.I had loosened the big brass jet but hadn't removed it.So they are now apart and the overhaul can continue on it's merry way.Again thanks very much Maleko and Fire Medic.Cheers Kevman.And thanks to NaughtyG for his writeup on the v4 forum.
     
    Last edited: Oct 6, 2018

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