Newby looking for stock performance help

Terry Jackson

I bought a pair of Sportsters this year, a 1996 XLH883 (13k miles)and a 2002 XL883 (2300 miles). The 1996 runs circles around the 2002. The 2002 lean sneezes occacionally, and accelerates better when backing off the throttle. It is a struggle to get it to 80 MPH. I got the manual and checked the carb operation and all appears OK. It still acts like it is too lean, or the timing is retarded (late). Otherewise, it sounds & runs OK. It does have the dealer installed freeflowing exhaust and breather (Screaming Eagle).

Anyone know about this problem or have any ideas what to check next?

glider

More than likely it needs to be rejetted.

CV Carb Rejet Pics - Harley Davidson Community

A 45/46 low jet and raising the needle will make a bear out of it. The hi jet should be upped one size too.

You should only need the replacement jets, don't waste money on the kits.

#46 JET

Even check this post too, it's a TC but it will give you some more input.

*Twin Cam CV Carb Rejet Suggestions - Harley Davidson Community

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Terry Jackson

Thanks
It looks like I need a larger main jet or smaller needle(metering rod).
Same principle as the old carter & quadrajet auto carbs.

Do I need to tear it apart for size identificaiton, then get the next richer size?
Or is there a kit that has several tuning options?

Sorry for the questions, just new to here, but an old boat & car mechanic (years ago)

Missed the part about raising the needle. How is this done?

glider

You could just buy the 45 & 46 low jets or just go with the 46 and be done with it. As far as the high speed jet, probably have a 175 in there now, next size would be a 180 but dropping the float bowl will tell for sure and save some time reordering jets.

Don't ya just love those Qjet carbs?

As far as the needle, look in the bottom of this post and it will show you.
CV Carb Rejet Pics - Harley Davidson Community
Run the needle "C" clip in the center groove and give it a try. You can also use a #4 washer or two under the 'c' clip fine tune it.

Take a look here
CV Carb Circuits - Harley Davidson Community


Quick and easy way of testing the main jet size.

Run the bike through the gears into third gear and run third up to 60-70 MPH full throttle, then chop the throttle about 1/8 to 1/4 back and see if the bike either surges ahead or stumbles then recovers.

If it surges ahead, your jetting is lean
If it stumbles and recovers , your jetting is rich
If it makes no difference, you're pretty close.

One other thing here, you probably have the non adjustable needle in the stock carb, the one with the nail type head on it. You can use 2 - #4 washers under the head of the needle to raise it up for a quicker fuel curve.

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Terry Jackson

Thanks again
I found and reviewed the technical section so I will probably be buying slow and main jets. Luckily, I'm only one exit away from a Harley dealer, and the original owner bought both of these Sporteters there. I've already had their tracking system changed to me. Both of these bikes were already in their system. It does surprize me they put on the high performance exhaust and air cleaner system and didn't rejet accordingly.

I'll fine tune it myself now that I know what to do & look for. The manual doesn't cover this at all.

Thanks again.

glider

It sounds involved but it's a piece of cake with your background. Any problems , give a shout.

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Terry Jackson

Glider;
slow jet was already a 45,but the main jet was a 160. I changed it to a 180, and drivability improved tremendously. It's wet here, so I could not stand on it, but part throttle response improvement was dramatic.

Piece of cake. Never been in a Harley and it only took 45 minutes taking my time.

almost $15 for the 2 jets thru the dealer. Next time I think I will order them.

Thanks again

glider

Did you shim the needle?

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Terry Jackson

No, I did not shim the needle. Since I was going from a 160 to a 180, I figured the mixture would be fatter all over. ( I used to grind my own needles on the Qjets). I might consider that later if I have any hesitation in any form at all.

glider

Shimming the needle just brings on the fuel a bit sooner and the high jet really doesn't supply fuel much down low (below about 1/2 throttle)

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