Top end hesitation

[MidMoBlaster]

Hello,
Over the winter I worked on my bike.
New jets 48/180
Shimmed needle about .050
Airbox mod, (cutout side walls and open up more) K&N filter
Rerouted crankcase breather line out of airbox
Denso Iridium Plug
Also have Vance and Hines exhaust

Bike runs MUCH better now, except around 65-75 MPH it hesitates a bit, (not backfire) kinda like the wind is blowing me back a lil, after that it rides ok again. Kinda intermittent at higher speeds only. If I give more gas this goes away. It still has power, but almost resembles a loose plug wire, although I checked and the plug is tight, and the wire is on snug. This hesitation issue is not too bad, but I never noticed it before.
Do I have the wrong jet sizes? Somthing elese?

Thanks

 

[pierce]

You might want to try 175 main. 180 is most likely running rich with your setup.

65 - 75 should be easy riding.

 

[MidMoBlaster]

Cool! Thanks for the quick reply

 

[MidMoBlaster]

Update: popped in 175 main jet, and bike runs smooth at high and low speeds now.
When I had the carb apart i noticed it has a 42 pilot, not a 48 as I previously posted.
Does a 42 sound about right for a slow jet? Would a 45 b any better?

 

[MidMoBlaster]

Ok, so the 175 main helped... But still noticed the hesitation, althou not as bad, so I went all the way back to factory 170, and its still there! Next I put the factory harley spark plug back in, removing the aftermarket iridium racing plug: this smoothed it all out!!

I tried multiple times now, only changed the plugs, I'm sure its that iridium plug giving me troubles.

What gives? What do I need to do to use this $30 plug?
For now I'm jus running the factory plug, but want the benifits of the after market plug (hp gain)

 

[MidMoBlaster]

Anybody know whats going on with this plug issue?

 

[ghostedrider]

Hello,
Over the winter I worked on my bike.
New jets 48/180
Shimmed needle about .050
Airbox mod, (cutout side walls and open up more) K&N filter
Rerouted crankcase breather line out of airbox
Denso Iridium Plug
Also have Vance and Hines exhaust

Bike runs MUCH better now, except around 65-75 MPH it hesitates a bit, (not backfire) kinda like the wind is blowing me back a lil, after that it rides ok again. Kinda intermittent at higher speeds only. If I give more gas this goes away. It still has power, but almost resembles a loose plug wire, although I checked and the plug is tight, and the wire is on snug. This hesitation issue is not too bad, but I never noticed it before.
Do I have the wrong jet sizes? Somthing elese?

Thanks

Anybody know whats going on with this plug issue?

here you go - you need to check that the boot is not leaking and also replace the plug wire with a p/n 15 N from auto zone ($5.00)- and re jet as follows for your mods .

also did you get the correct heat range plug ? - if it's too hot it will cause problems .

you want the IXU27B - regular Iridium, or

IXU01-27 - the racing plug which is the bomb

For Aftermarket Exhaust AND a hi-flo intake or Modded Stock (EZ mod)...

Since you didn't mention adjusting the air mixture screw that is probably part of the problem.

...rejet as follows: -- for your level of mods --

Below 5000' altitude - 45/175

shim needle .05" (aprox. 2 brass #4 machined washers), air screw at 2 2/3rds out from light bottom

=====================================

Accessing air mixture screw-

Carefully remove plug over idle air mixture screw (drill it out carefully)

and reset idle mixture screw to 2 1/2 turns from fully seated,or for best idle speed.

If best idle is more than 3 turns out, switch to a 48 pilot jet and re-adjust idle screw for optimum idle.


FAQ - INFO - MOD'S

 

[MidMoBlaster]

Cool, thanks for the reply.
I have a new boot installed I put on over the winter too, so i know thats good.
I did set the mixture after rejetting, started 2 1/2 out then adjusted by ear, just didnt mention it
Also the plug i have is the IXU01-27 racing plug, are there dif heat ranges with this model plug?
Ill replace the plug wire 2nite