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I have a 107" S&S engine in my 1989 FLHT. Thunderheader exhaust and Dyna 2000 single-fire ignition. Super G carb.

I recently had the Thunderjet installed by Zippers, and I'm having trouble getting it tuned properly. It runs well up to 2800 rpm, then stutters badly in fifth gear up to about 3200 rpm when it smooths out. I have a .33 intermediate, 84 main, and 125 air bleed. I think it is too rich during the transition to the main jet which is coming in too soon because of the 125 air bleed. Does anyone out there have any suggestions?
 

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0043--Licensed to Doof!
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Drop that 84 to an 82. What's in the thunder jet?
 

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Not sure what's in the Thunderjet. Whatever Zippers sent. Chart says between 120-140.
 

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MaxHeadflow
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Sounds like you are way rich. I'd use a 31 int, 150 air bleed. Cut the man to a 78. Also cross drill the air Tjet air bleed. (2 holes in the Tjet tube to 0.055).. It might be best to tune the bike with the tjet soldered close.. When you get it running good from idle to 4500. open up the Tjet.. Make sure you set up an external bowl vent also.. Bruce
 

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155" R&R TwinCam
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Sounds like you are way rich. I'd use a 31 int, 150 air bleed. Cut the man to a 78. Also cross drill the air Tjet air bleed. (2 holes in the Tjet tube to 0.055).. It might be best to tune the bike with the tjet soldered close.. When you get it running good from idle to 4500. open up the Tjet.. Make sure you set up an external bowl vent also.. Bruce
Bruce,drilling the ThunderJets? what is the purpose for this,where are the holes drilled? Dog
 

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I think Bruce is refering to the spacer below the threaded plug that
houses the thunderjet-Jet.
so You have a 125 air bleed (on side of the carb) ??
that seems very low. I would follow Bruce with His recomendation of the 150 air
bleed. I would try that before leaning out the intermediate jet.
 

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drop main jet first! try 82. let us know what happens and what you end up with.
 

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I have a too rich problem also. I've seen all kinds of post on the settings. I currently have a .066 main jet and a .0265 intermediate jet. External air bleed is .150 thunder jet air bleed jet is .120 Still running rich. Don't know what to do now. I'm running 2 and a 1/4 inch drags. Gonna try baffles and see if that helps. Any suggestions would be appreciated.
 

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You're gonna have problems tuning that bike. The thing that stands out the most to me is 2 1/4" drag pipes?? On a 107?? Good God...... Unless your peak rpm is is 8000rpm and a ridiculous top end cam that's a no go your bike doesn't even know it has a pipe... Lol... If you want to go open drags you should drop back down to 1 3/4" inch pipes and keep them mid length or longer at least past the trans by four inches. Even at that may need the old lollipop drag baffles. What you have to understand is that dragpipes sound great and they work great for power But...they are only good for a bike that has a high rpm cam. They only make power above 4500 rpm. So unless you are screaming around wide open they won't fit your purpose. It would help to know how your riding it to get it dialed in for your style of riding
 

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not enough info to even venture a guess...
your exhaust is killing the power,, and ability to tune it
do you know what is in the engine?? s&s bottom is no help,,, stroke.and bore are...
we would gladly help,,, but have no info
 
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