Hey Guys, bought this showroom looking beauty at 32,000 mi.
been doing my own mods and maintenance. Almost have her running perfect.
Upgrades to Screaming Eagle Big Bore. 10.25/1 Carrillo pistons. 211 cams and the tensioner upgrade. Has street port heads done by a local.
My problem is since the upgrades she runs real rich. Gas mileage sucks and alotta backfiring on deceleration.
All that to ask.....
Where should I start with new jets? Thinking 180 main and 45 pilot? Too lean for the Bb kit? Any suggestions? I don't wanna change these 50 times. Have no idea whats in it. If the guy that put it together for me left stock jets or even upped em? Was hoping you pros could help resolve my issues. You guys have came through for me before so i have high hopes.
oh, and where's a good place reasonably priced for new jets.
Thanks so much. I'm having a blast doing my own work.. new bars, led turns, tires, rotors, brakes. Got rid of the wobble with new tires... old ones were stock from the factory. Yup 20+ years old. Also did the neck bearing adjust so no more wobble at 80. Freeking rides so smooth. Hauls *** now too!
Thanks again fellas. Look forward to your input Darrell

 

Got a photo of the spark plugs? Runs up to redline and does not buck and stutter? it's for the most part not that rich then. So the smart move is a fresh set of plugs and then take a run at it for the day and pull them to see the color.

 

Similar mods / 98"
running 48/190 with the n95 Needle
42-50 mpg

 

If you mentioned it I missed it, but I am assuming you have an OEM CV40 Keihin Carb. I find that carb to be under appreciated.

Here is a web site with tutorials on how to tune a CV40 carb... They also have parts; tuning kits, rebuild kits, jets, and needles.

If you follow the process, the CV40 carb is rather easy to rebuild & tune... Good luck and enjoy the bike!!

https://cv-performance.com/instructions-guides

 

Hi guys, gonna go pull the plugs and jets to get a better idea where I'm at. Will post photo(s) for ya.
Appreciate all the quick and informative replies. Thanks for the links too. Love this place and my generous HD Bro's.
Gonna do some suggested reading and pull parts for photos. Be back soon. Yep, factory CV40.
Darrell.

 

Plugs look very consistent. Rich but consistent. Might explain the 1/4+ turn out pilot screw???? Little loose on the gap .44 but, I expected that at 1500+ miles on em. Tips of both plugs were loose so I tightened em up and cleaned the deposits off best I could. Opened the pilot up to 2 turns out. Idles too low now but that was cold so I left it alone for now. Gonna go for a scoot. Throttle response is real tight. I like it!
Guess I made on he'll of a smart move by posting here for your comments! Didn't just tear into it throwing un-needed parts in there. I am of the opinion these CV carbs are pretty darn good tools. But, what the he'll do I know. 1st Harley ever....lol
Hey thanks again guys. Ya can't get this kinda love from Harley..... unless you have Elon's kinda cabbage!
If I'm missing something throw a shout out. I'm ALWAYS humble enough and open minded enough to intake any and all advice.
Best, from a Seattle-









ite!

 

1st 7 photos from the rear bank. Last one is front bank by the way....
Harley manual for this year Softi says 45 pilot, 190 main and plug gap .38-.42. I went with .40

 

Ok, well.... 2, 2-1/2 and 3 turns out the backfire popping decreased a little but, still very present.
what ya'll think? Move up to a 48 pilot? 50...105?
want this crap gonnzo!
Do not wanna lean her out anymore....

 

Plugs look good. No sign of too rich nor too lean. Too much turnout can loosen the spring and the needle walks out of the carb body. More like needing an rpm meter. Depending where the air screw is, meaning, on the air cleaner side of the carb body is air, So more out is more air or lean, Needle on the head side is fuel, screw in less gas.

The point of turnout is the middle of rise in rpm of say 25 to 50 rpm (is why the meter) and say out the rpm rose and then stopped, Then turn in and it drops rpm. So you turn it out in the middle of high/low rpm ranges. It's not a random turn out and stop, but to chase those few rpm drops,

 

I'm lost... there are 2 adjustment screws on a CV40? The only one I know of is right next to the cyclinder. Ya put the main and pilot jets in. Run this screw out about 3 turns. Run her up to operating temp then dial this screw in till she stumbles then back out till she runs like crap. Split the difference in the amount of turns and that's the sweet spot...