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Discussion Starter · #1 · (Edited)
It's an 01. I have a custom 4-2-1 exhaust with a stock airbox. Exhaust is much larger than stock after combination. Lots of bogging at full throttle. Lots of bogging at partial throttle near 6-7k. Takes off great from idle. Idles well. Lots of popping on deceleration.

Motor doesn't come up to temp driving around. Highest I hit was 170. It takes a loong time but will kick the fan on around 220 if I let it sit and idle.

Bike sat for a while before I got it.

Clean carbs first or also adjust needle clip position?

Sounds like it's going rich right?
 

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teke the carbs somewhere that has one of the ultrasonic cleaners and have em cleaned. issue sounds like its on the main but the main jet is big and hard to close so it may be an air passage.
 

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Discussion Starter · #3 ·
teke the carbs somewhere that has one of the ultrasonic cleaners and have em cleaned. issue sounds like its on the main but the main jet is big and hard to close so it may be an air passage.
I'm gonna pull the carbs tonight and clean the mains. The motor just isn't revving under load. I got to drive it a bit more today. I ran some seafoam through and it got a bit better but it's still cutting out around 5k and above. There's a considerable deadspot above that. Plugs have a good bit of carbon buildup but are dry with a slight tan spot on the porcelain.

I've also got an wideband I'm gonna stick on the tailpipe next drive.
 

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Discussion Starter · #5 ·
Well, the carbs are clean and the plugs look ok but will be replaced shortly. I scavanged a 1k ohm resistor and put it across the fuel sender pins. I can now rev past 8k rpm. There is definitely a fuel or ignition cut there if the fuel light is on. I believe I need more fuel in the midrange I and when I confirm that with a wideband I'm going to raise the needle jet one clip at a time until my 1/3-3/4 throttle improves.
 

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Clean the carbs (properly). Dont mess with the needles yet. double check the EXUP cables are not binding and that the flap will open fully by hand (if the EXUP is on the aftermarket system which probably isnt the case. Verify the fuel line is not kinked and that there is no crap jammed up in the petcock. The temp being at 170 isnt the cause. If anything, it is running on a slightly more advanced timing l cell, which is what you need already due to the exhaust system you have. You do those things, you will find and fix the problem. Unless its not jetted, which would be a cause for concern.
 

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Discussion Starter · #8 ·
Thanks for the reply!

Carbs are clean. Fuel line is not linked. Exup is deleted. I am going to shim the needles to correct the afrs being off due to the custom header and exup delete. Thoughts on an ais delete? Just cap the 4 plugs correct?

I was going through the ignition system and the plugs were gapped improperly. I gapped them properly and the problem got worse. New plugs and we are getting better. Checked the coils and literally cannot get a reading on the secondary. Primary coil readings are off by a good bit as well. Waiting for new ones to arrive. I will update.

Btw, the motor isn't in a bike anymore. Hehe
 

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Discussion Starter · #9 ·
Well, an update. I don't have coils yet, but I pulled the AIS and the problem is almost entirely gone. Im going to swap coils when they come and then a wideband gets installed on the header for tuning the carb.
 
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