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Discussion Starter · #1 ·
anyone tell me jet sizes for 80ci softail? bike had a 42 slow and a 165 main ran terrible, I went to a 48 slow and 195 main runs good other than lil slow up top 70mph up and fuel mpg is 28 lol
 

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Classic symptoms of running rich. Try 175 main, 45 pilot
 

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While I'm not sure of your other enhancements I was having issues at top speed, actually had to let off a little on the throttle as it was looking for fuel. I have a mild/mid cam, hi-flo breather and 50/50 Samson mufflers on a 97 evo road king. When I upped the main jet to 190 it solved my issues. You will see a drop in mph especially from a 165 to 195 but it's better to have a dialed in engine than not.
 

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Discussion Starter · #5 ·
I went with a 45/185 then a 45/180 really seen no diff from either except af screw needed to be adjusted on out, it does climp better up top I guess it was too fat originally with the 195, has kn filter and vanxce short shots, I also noticed a couple few carb farts blippin throttle at a light, also on highway let off throttle and grap it again theres a little surge there too, maybe back to the 48 slow, and leave the smaller 180 Main
 

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I went with a 45/185 then a 45/180 really seen no diff from either except af screw needed to be adjusted on out, it does climp better up top I guess it was too fat originally with the 195, has kn filter and vanxce short shots, I also noticed a couple few carb farts blippin throttle at a light, also on highway let off throttle and grap it again theres a little surge there too, maybe back to the 48 slow, and leave the smaller 180 Main
If it surges when you let off from full throttle, main jet is too lean.
Try keeping the 45 pilot and using the 185 Main.


Also, make sure you don't have an intake leak before changing jets.
 

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Discussion Starter · #8 ·
update

with the 45 slow jet bike would cough out carb and when let off throttle then back into it there was a surge, backed out af screw never could get rid of this, I don't have a 46 to try but I do have the 48 so I put it back in and fixed never burped or surged once although af screw is only about a turn n half out now, as far as the main jet I tried a 170 and clearly too lean as let off throttle it pulled better, currently at 48/180 seems to run fine here, ran it 90 miles today filled up with gas and low n behold 3.012 gal gas, so still pretty much 30mpg, im wondering id prev owner had cams installed? everywhere I read 48 slow is too much for stock evo? mine has to have it to do away with carb farts and surging, so I dunno but the mpg seems really bad?
 

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Discussion Starter · #11 ·
back on the 48 slow and 185 main bike runs and pulls the best with these, no more carb farts and pulls throughout, prev owner must have bigger cams in this bike as it loves the 48 pilot runs well here
 

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Discussion Starter · #12 ·
pulled plugs and they are very dry and even grey white on tip, how can this bike be lean with a 48/185? no intake leaks that I can tell, and runs perfect idles perfect, surely this evo wont require a 50 slow jet? it does have a screamin eagle air filter and new vance hines short shots staggered pipes baffles in, started it up sprayed wd40 all around intake no leak idle remained steady
 

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Discussion Starter · #13 ·
so today I sprayed carb cleaner with bike running around the intake flanges and it would stall motor everytime, but bike ran fine, so I went dealer got all 3 new rubber gaskets installed them left the same 48/185 jet combo and I see no diff in the running? wondering since it was leaking if I can go down to a 46 pilot or even a 45?
 
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