mikuni jetting
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mikuni jetting
I've got a 98 flht that I just rebuilt the engine on. I went 9.5:1 compression ported heads and oversized valves, and i'm running an ev27 cam and dyna 2000I Ignition.
I went with a 45mm mikuni and currently have a 32.5 pilot jet and a 180 main jet and the needle clip is set on the next to richest spot. I've checked for intake leaks and found none and it still seems to be running lean and is flat with a 60mph roll on doesn't miss or backfire or cough or anything just doesn't have a good roll on get up and go. bike starts without choke and goes straight to idle.
So is it posable that I need bigger jets still?
I went with a 45mm mikuni and currently have a 32.5 pilot jet and a 180 main jet and the needle clip is set on the next to richest spot. I've checked for intake leaks and found none and it still seems to be running lean and is flat with a 60mph roll on doesn't miss or backfire or cough or anything just doesn't have a good roll on get up and go. bike starts without choke and goes straight to idle.
So is it posable that I need bigger jets still?
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From: Ohio
If you are lean it will rattle at a 60 mph roll on and will spit out the carb cold, you are flooding it with a 45 at that setup, move the needle to the center slot and a 180 is way too much for that engine. I was over 100 hp and running a 165 or 170 with a 45 tuned with a AFR reader, will confirm the size tomorrow by looking at the jet box.
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I run HSR45 stock engine, but K&N cleaner and V&H open pipes. I know, carb is way too big for evo but I have some reasons to do that.
Pilot jet 27,5 and main 165. Needle clip in middle. Runs fine, not lean, good mpg.
Pilot jet 27,5 and main 165. Needle clip in middle. Runs fine, not lean, good mpg.
Last edited by unnnivers; Sep 28, 2014 at 02:44 AM. Reason: ...
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From: Bluffton, South Carolina
What is the accelerator pump set at?? Have you checked your timing? The larger carb can make the engine more timing sensitive.
Download the Mikuni tuning guide and follow the steps in there. You will learn a lot and get the bike running as good as possible.
John
Download the Mikuni tuning guide and follow the steps in there. You will learn a lot and get the bike running as good as possible.
John
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From: Ohio
At the numbers you are listing it should be melted by now, 13.8 with some compression or 14.2 with a stock type engine is a target going down the road. New bikes are at 16-1 and lean for EPA reasons, 24.5-1 will cook popcorn if it runs at all. Unless you have that intake leak or a vacume cap come off, the gauge is goofy because those jet settings are flooding it
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89" 10.2-1 comp, head work, Woods W6H that runs well, 32.5 with a 50 accel jet, Yost aggressive needle and a 167.5 big jet. Provides nice AFR numbers with a 13.2 WOT, had a 170 in it and AFR's dropped into the 12's and butt dyno felt it flatten out
Pull those plugs and check them, attached mine with these settings.
Pull those plugs and check them, attached mine with these settings.
Last edited by 1997bagger; Jan 26, 2019 at 11:58 PM.
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guess I'll just leave mine set up the way I've got it, my plugs look pretty much just like the one posted above.
I do want my stuff running correct so for everyone saying that I'm flooding it, shouldn't that foul a plug if that were the case?
with my afr set up I've got an exhaust probe that seems to work with everything else I've got but maybe with the v&h cans on the bike their is a dead air spot or something right where the probe stops, I may try changing the length of the probe or drilling small holes along the tube or something to see if it will get a better reading.
Thank you for the replies.
I do want my stuff running correct so for everyone saying that I'm flooding it, shouldn't that foul a plug if that were the case?
with my afr set up I've got an exhaust probe that seems to work with everything else I've got but maybe with the v&h cans on the bike their is a dead air spot or something right where the probe stops, I may try changing the length of the probe or drilling small holes along the tube or something to see if it will get a better reading.
Thank you for the replies.
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