MoCo tax and rejetting
Harley Evo SportsterDiscuss MoCo tax and rejetting in the Harley Sportster & Buell forums; I finally got a steal on ebay for a K&N filter so now I have the other half of the MoCo tax taken care of. But before I put it ...
I finally got a steal on ebay for a K&N filter so now I have the other half of the MoCo tax taken care of. But before I put it in I was wondering if anyone could recommend jet sizes. Right now I don't have the time or funds to go on an endless jetting expedition, so if I can get it narrowed down a lot it would be a great help.
If your running the stock CV carb on relatively stock Sportster a 45 slow jet and 180 main should get you in the ball-park...and you MAY want/need to lower the clip on your needle (raising the needle) one notch to fatten up the mid-range OR get (as I've been told) the needle for an '89 (as I recall) Sportster carb...best to double-check me on that model/year thing though.
Oh,and..IMO would'nt recommend wasting $$ on any "special-spark-plugs" (that ain't gonna make any noticeable difference) at LEAST 'til you get everything dialed-in,to suit you...or EVER for that matter.
__________________ "If at first you don't succeed, try again...then swear"
Mark Twain
Ken got it. Did you get the K&N backing plate or just the filter ? What pipes do you have or plan on getting ? You will need to pull the plug so you can get to the mixture screw on the bottom of the carb. The 45 low speed and a needle change may be all you need. If you know someone who has rejetted a twin cam they probably have a 45 they are not using. The needle is part no. 27094-88. At your elevation you may not need to change the main jet at all.
You can order jets from J&P for $2.98 each. I don`t think you want to go bigger than a 45 at 4.00 a gal. Agree with Ken on spark plugs.
If you are just changing the filter and nothing else I would change the needle and adjust the mixture screw and leave the jets alone.
Wright brought up a good question that I had'nt "thunk" of. If you just got the K&N filter w/o the relieved backing-plate you might want to neatly drill evenly spaced 1/2" (or larger?) holes around the outter edge/perimeter of your stock black plastic "air-box" and even a few on the back-side,where incoming air would still get filtered. This worked well enough on my son-in-laws 883 with K&N filter and Cycle Shack slip-ons (which is very similar to the set-up you've described) and looks pretty cool,too.
__________________ "If at first you don't succeed, try again...then swear"
Mark Twain
THe best drill bit I have found for that and other applications is a uni-bit or step bit. There are several makers of the bit such as GreenLee, Lenox, Ideal, Etc.. Easy way to pick one up is at an electrical parts sales place, and I think the Home Depot has them. A little pricey (about $40-60) but well worth it. You'll use the **** out of it.
__________________ "HELL IS EMPTY, ALL THE DEVILS ARE HERE."
As far as the plugs, I'm sort of a "gadget" guy. I don't fall for snake oil, things you drop in the tank, or make your fuel mix turbulent, but the Pulstar plugs have me curious. I know when I went to Splitfire plugs it woke up a few ponies that must have been snoring away somewhere, and the Thundervolt wires I got helped, and the BarSnake cut down vibrations that were making my dentist rich from losing fillings; so I just want to see what happens. Sometimes far out things work the way they're supposed to.
My wife has a 05 883C. SE Slipons and SE Aircleaner. I am running
#175 main and a #65 pilot. Needle is was left stock. I would only go higher then a #180 on the main if you bored or converted to a 1200.
Like the rest said. If its just the filter you will have to modify the back plate to get the benefit out of the filter.
Without taking it apart and looking....Again. I went back to a post on carb rejetting I replied to last year in may of 07.
Both bikes had the carb farts going on. I pulled a #62 pilot jet out of both the 883 and the 1200 and replaced with a #65. #180 main in the 1200 and #175 main in the 883. The #?2 pilot was stock.
Both bikes run good. No more carb farts and the plugs look good. I did the Frisco plug check where you run the bike shut it off and coast on over and pull the plugs.
Now this was over a year ago I could be wrong. I know I double check before I post as to not steer someone wrong. However I do go brain dead on occasion. Now that you mention it a #60 or above sounds excessive. A #42 replaced to a #45 sounds better. Typo? Geez when I get back home I will have to check. So until then......I am not 100 percent sure on what my pilot sizes are. I am 100 percent sure on the main jet.
It may be a bit before I get back home to verify. Ken I believe you are correct. Thanks for the catch.
Geez,JC:
Did'nt mean to send you home to tear your carb apart just thought ("ouch") I'd help out a little here.
Don't think of it as being "brain-dead"..more like a "brain-fart"..I get them all the time !!
I would'nt bother checking,your pilot/slow jet,etc..Wright,pretty much confirmed (indirectly) that #45vs65 was about right in his post here..you seem to think so now..and, I have no doubt#175-180 for your mains are in the ball-park,too.."get over it" and get some sleep,buddy !!
__________________ "If at first you don't succeed, try again...then swear"
Mark Twain
MoCo tax and rejetting 
just thought ("ouch") I'd help out 
a little here.
!!
and get some sleep,buddy !! 
Linear Mode
