Want good tone/Not noise - Harley Forum

coot · #1 10-18-2009, 01:42 PM

My '02 CARBURETED 88in FLHTC got the SE intake and some SE slip ons that sounded really good. And the bike ran great for a stock bike. But as great as it sounded, it was too loud for me. Sorry to all you loud pipe guys out there. So, I tried putting on some '08 model Street Glide slip ons. I thought that since they were tuned for a 96 inch motor they would quiet my bike down without hurting performance. Boy was I wrong. Whenever I rolled on the gas, the power was squishy and it was slow to respond. Too much back pressure I suppose. Sort of like pissing through a sponge. Even after I perforated the baffles in both mufflers quite extensively, the power was still not there. Then I found a set of CVO 110 mufflers from an '09 and the exhaust note is FANTASTIC!!! And my brain is no longer hammered by the high db.
There is still a hint of my back pressure problem. But nowhere near as bad as before. So I am wondering what to do to my carb to help this. Should I go leaner or richer in the mid throttle range? I do not believe that I need to do any changes to the high speed jet since WOT is not my problem. Is there any way for me to raise the needle to change the position of the taper to achieve this? I mainly ride two up between 2000 and 3000 RPM cruising and want to maintain the GRUNT torque on the low end. But I don't want it pushing back at me.
Huh?

jimkelley · #2 10-18-2009, 08:50 PM

Hey Coot! In another thread I posted, mainly dealing with high altitude carb jetting. I believe Dennis Kirk (denniskirk.com) still sells Dynojet kits. The kits feature a new needle that has a sharper taper for a little quicker throttle response. The needle has three separate points for attachment and a nice selection of main jets. I installed the kit when I switched to a high flow air filter and V/H Oval slip-ons. Those were the only mods I had made. My scoot was an '03 Electraglide. I had to experiment with the needle setting and jet size a little. The kit had a pretty good tutorial set of instructions but a good book on CV Carb troubleshooting would be a big help. You can also find pretty good info on the internet. Good luck with the project. By the way the Vance and Hines Ovals have really good sound but aren't too loud for most folks.

coot · #3 10-18-2009, 09:19 PM

You are right. The V&H Ovals are nice. SuperTrapp has a great tone too. And I admit that BUB/Rinehardt is good too. But as luck would have it, I stumbled onto these original HD CVO 110 slip-ons through e-bay and since a buddy of mine had already done the same thing, I knew that they would sound perfect for me too.
As for the carb, I appreciate the tip on the Dyno-Jet Kits. I already have almost every jet that I could ever need for any CV or KeiHin. But I wasn't having any luck finding my needle solution. I didn't want to just sit down and sand it or file it till it was right. I used to do a lot of needle tuning on Amals, Kehins, and Mikunis back in my racing days.
I'll try to locate some more needles and try them. Then I might have to richen up the low speed jet a bit since that is where 99% of us operate. It is my opinion that the high speed jet is just fine until you do head work. Then a higher flow rate can utilize a bigger jet.
Once I get it figured out, I'll post the recipe details. But my guess right now is that it needs to be just a hair richer in the mid throttle position. And the right needle would be better and more accurate than changing the low speed jet.

frisco-rigid · #4 10-19-2009, 02:47 AM

Hey Coot

This link gives one of the the best descriptions of jetting a CV Keihin,, try it on for size..

CV Carburetor Modifications

Remenber Pat Bradys Jeep in the Roy Rogers days.?
Name was Nelly Belle..

coot · #5 10-19-2009, 12:02 PM

Thanks for the link frisco-rigid. I'm gonna use it. After thinking about my needle situation, I may just leave this one in place and put the next richer low speed jet into the carb. The taper I have installed may work fine with a slightly richer jet. Otherwise, I'll need to install a needle that gives me a richer mid throttle condition.
And yes! I do remember sitting at home watching Roy Rogers, Pat Brady and "Nelly Bell".
Every one of my mechanized vehicular contraptions has its own personality. So each one has its own name. Nelly Bell is a pretty thing that gets me where I'm goin' in style. And I know it when she doesn't feel right.

aceharleywrench · #6 10-19-2009, 03:59 PM

Try H-D #27094-88 in your carb.This is a needle for a 1988 1200 Sporty,this will give you the midrange you're looking for.It retails for right around ten bucks.Or you can always try shimming your stock needle with small washers,I've had success with that in the past.

coot · #7 10-19-2009, 04:32 PM

Thanks for the part number Ace.
Is that needle shorter than the one in the 88?

I don't know about y'all, but I kinda liked the old Amal & Kehin needles with the grooves & the clips. They got the job done without having to have a bunch of needles laying around.
I'm heading out to get washers now. Do ya think .050 is enough to notice a change?

frisco-rigid · #8 10-20-2009, 01:58 AM

Hi Coot

Using a weeee richer Low-spd jet with a slightly leaner needle is as old as the hills,, give it a try cuz as you know,, the straight portion of the needle is mostly used in easy cruise mode,,, the power comes when the needle rises..
And, I've always found a weee/slightly fat Low-spd aids in starting and "off-the line" accell..

.050" of shim washer might be just fine..
The Notches in the Mikuni needles are approx. .040" apart..

When I move the clip just ONE notch up or down in my Mik's I get a pretty big diff in running and about 2-3 MPG diff at 1/8th throttle..
Just .040" more into or outa the taper..

Ace's sugg't is good too..

coot · #9 10-20-2009, 10:17 AM

Thanks man. This pretty much confirms my conclusions too. But it's sunny & 60 deg F today. So me & Nelly Bell are gonna put it in the wind. I'' take the CV down this weekend when that danged fizzled hurricane comes to visit for a couple of days.
I am also discovering that the old CV has been drilled for some form of kit. So I'm gonna have to do some measuring before I put a recipe into action.

Now, as for the effect I am looking for. I am not looking for grunt off the line. I don't work my Nelly Bell this way. But I am looking for more "Roll-On" power from 1800 up to 3400. So my actual throttle position will be crucial to getting this right. I really don't want to have to "custom grind" my own needle to get the taper just right. I was hoping to get lucky & just hit on the right combo.
Does anybody have any suggestions as to how I go about figuring out just how high my slide is when I am cruising at 1800 rpm? Everything's different when you're rolling and not on the stand. (I don't have my own Dyno)
Otherwise, I'm gonna have to use the old crayon marks on the grip & switch body to try to calibrate it that way. (Jeez......that's REAL precision...ain't it?)

"The future ain't what it used to be....." Yogi Berra.