Thunderslide Kit
My local guy finally talked me into buying a thunderslide kit for my bike (although I'm still not convinced it's worth the money):

1991 FXRS
24,000 miles
Stock Keihin Carb
S&S Air Cleaner with K&N filter
EV3 cam
Screamin Eagle Adjustable pushrods
Stock Exhaust
Screamin Eagle Iginition Module
Screamin Eagle Ignition Coil
Stock ignition
Magnecor Wires
I live at around 4,500-5000' elevation

So anyways, I installed the kit and started with the needle in the #3 notch (there are 7 total notches on the needle). My guy told me to start with the 175 main jet and keep the stock 42 slow jet.

So I took it for a spin.........all kinds of farting on deceleration.

Went back and shimmed it in #4 (shims are numbered from #1 being at the top of the needle and #7 being at the bottom, so going from notch #3 to notch #4 would "raise" the needle).

Took it out for a spin.............little less farting on deceleration.

So by the time I finally eliminated the popping on deceleration I was all the way into the last notch (#7). My thoughts are that my needle is shimmed way to high and that I should switch to a 180 main jet and a 45 slow and raise the shim back up to #3 or #4 again.

My local guy told me to leave it as is and ride it. Problem is that when I run wide open I'm frying plugs and then the bike runs like hell (sputters on acceleration) until I put in new plugs.

With the current set up the front plug is starting to tan up a bit, but the rear plug is black and sootey.

Any thoughts???

 

i think its too small of a pilot jet. my 883 had a 42 in the carb and it was way lean for it!

id say you should go with a 45 pilot jet. as for the kit ive not heard good things on it.

ive always bumped up both jets and drilled out the mix plug and richend the idle mix

by turning the hidden screw out a couple of times.

its worked on my old sportster and my dads 88'superglide.

 

thanks for the reply,

tonight i upped my main jet to a 185 and my slow to a 48 and shimmed my needle at notch #3.

works like a charm now...............good response and HP throughout. haven't checked the plugs yet but i would assume they are tanning up nicely.

thanks again,