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ATC with TB-88cc WOT bogging

865 Views 8 Replies 5 Participants Last post by  SS LS1
I have an ATC70 with the TB 88 big bore kit and it never ran very well with the Chinese carb it came with so I put a mikuni VM 20 on it after some recommendations.
I've got the idle and pilot jet nailed down but it was still really boggy mid and upper throttle.
I moved the needle down 1 notch from the middle and that improved quite a bit but it still bogs at WOT. I bought 2 different jets kits and it seems to run best with the 185 main but still bogs. I've gone up to a 230 and didn't go further because it ran terrible and the same when I drop the main jet below 170..

Im beyond frustrated with this thing and hoping someone can offer some advice..
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You have to be rich.
I did the same thing before with a VM 20 on a 117cc. Kept going bigger...turned out I had stepped past the right sized jet thinking I was still lean. I think I ended up between 140-160.
1 - 1 of 9 Posts