Need advice, .48 Pilot jet

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Apr 15, 2014 | 04:33 AM

BootheatsBUGS

Thread Starter

Cruiser

Joined: Mar 2014

Posts: 218

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From: Michigan

Need advice, .48 Pilot jet

Been discussing this on another forum. I added the CVP velocity needle and 48 pilot jet to my stage 1 06 1200. It runs great! Everyone is telling me that there's no need to go above a 45. Before when i had my 45 in, I had my mix screw turned out 4 turns, with no change in performance. I was still getting carb farts. I've read about every relevant google search I could find and saw people running pilots as big as 50!!!

I checked for intake leaks with WD40 and had no RPM changes. I was told to check with propane instead, going to do that in the morning.

Now if I close off my mix screw the bike stumbles, and I currently have the screw about 2 turns out. Is there something I'm missing? When I tuned my carb today it was 60* outside.

So is a 48 too big for a sporty?? How many of you are running the 48 pilot?

Apr 15, 2014 | 06:24 AM

cHarley

Club Member

Joined: Feb 2007

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From: Boynton Beach, FloriDuh

IME, a #48 in a stage 1 1200 means you are masking a problem, most often it's an intake leak. My dyno tuned, 100hp "stage 3" 1250, with the CVP velocity needle is dead-on the A/F ratio with a #45.

When checking the manifold for leaks, also remove the carb and pull off the rubber manifold boot behind it. Use your fingers to open it up and inspect closely, they tend to develop cracks after several years that are hard to see.

Has your carb been cleaned and rebuilt?

Apr 15, 2014 | 03:40 PM

ClodeV

Tourer

Joined: Mar 2013

Posts: 320

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From: Muskegon, MI

i have a 50 pilot in mine from a 45 per the stealer. i have a 2000 XL1200. Did this due to a little coughing that was happening at low rpms. It also dyno'd a little lean prior to the pilot jet change. I run a 170 main. The bike is carb'd no efi.

Apr 15, 2014 | 04:00 PM

dwagar

Road Master

Joined: Jul 2011

Posts: 1,030

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From: Calgary AB

I'm running a 45, Dynojet needle raised up a couple of notches, 185 main.

When you changed the pilot jet and the needle, did you try it first with the 45 and the new needle?

Apr 15, 2014 | 10:58 PM

BootheatsBUGS

Thread Starter

Cruiser

Joined: Mar 2014

Posts: 218

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From: Michigan

Carb has been rebuilt. Checked for intake leaks with propane and wd40, nothing. Needle shouldnt effect anything off idle.

Im going to stay with the 48 and just keep on eye on it. I've been through everything trying to stay at the 45, but my mix screw was 4 turns out + and still coughing, so I gave up.

Apr 15, 2014 | 10:59 PM

BootheatsBUGS

Thread Starter

Cruiser

Joined: Mar 2014

Posts: 218

Likes: 1

From: Michigan

should have mentioned my bike has 100% new gaskets through the carb back to the manifold.

Apr 16, 2014 | 07:50 AM

Thumper87

Cruiser

Joined: Feb 2014

Posts: 113

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From: RI

It sounds like you have made up your mind to stay with the 48. With thatbeing said I would ride 100 miles or so then check your plugs and fuel mileage.

On a side note, I just went through the same issue when upgrading to a DK587 air cleaner and adding thunder torque's to my drag pipes. The existing setup was a #45 pilot and #170 main with what I believe (bought used) was adynojet needle with the clip on the third slot down. I went to the dealer andbought the Keihin jet kit that came with a NOKH needle, #180, #175, #48 and #45jets. I replaced the emulsion tube with the Keihin tube and #175 main and putin the new #45 pilot since I already purchased it. I shimmed the NOKH needle.040 and started at 2.5 turns out. I still had a few carb farts off idle butnothing compared to what it was. After unsuccessfully adjusting the AFM screw, Irealized there was probably a dynojet spring in there or the spring had beenmodified. I ended up buying a stock spring and comparing. The exiting springfelt lighter and was shorter. I pulled the shims out and went up to a #180 mainand haven't had any problems with carb farts. I feel the bike is running alittle rich right now (poor mileage/somewhat dark plugs) so I might back offthe mixture screw a half turn or go back to the #175. After you put some mileson your bike and if you decide it’s too rich I would try different needles suchas the N65C, NOKK, NOKH and shim combinations with a #45 pilot or just shim upyour current needle. I understand the jet needle taper controls the mixturefrom ~15% to WOT throttle but the straight diameter of the needle will control themixture from idle to ~50% throttle. Changing out the needle, bumping up themain and then ultimately going back to the stock spring worked for me. I do notthink just changing the spring would of cleared things up for me.