Best Performance Mods for an Ironhead?

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Aug 16, 2008 | 03:04 PM

#21

SportsterBob

Club Member

Joined: Feb 2008

Posts: 18,575

Likes: 4

From: Norfolk, VA

Quote:

Originally Posted by Mario77746

Ok, the bike was put on a dyno and the air/fuel came back at 11/1 mid range. I have a 26 intm jet and a 68 main jet. Again, the internals are stock. I have straight pipes, crane single fire ign and a velocity stack. Where do I go from here other than getting a CV carb for now????

I started out with a .031 Intermediate and had to go to a .033 (S&S "B") after porting the intake manifold and cutting the valve seats. The "E" model usually operates OK with a smaller Intermediate but overall it's difficult to troubleshoot via the keyboard. I didn't know your intermediate was a .0265!!!! That seems rather small....S&S reccomends shuting off the accelerator pump when tuning the "E" and it is REQUIRED to get the carb jetted properly.....The accelerator pump can cause "false" rich conditions that lead to under-jetting the carb!

How many turns out is your mixture screw? The S&S "E" on my B-T is so sensitive that 1/16 of a turn on the mixture screw is the difference between the plugs burning dark brown and light gray!!!!

Aug 16, 2008 | 06:15 PM

#22

Mario77746

Thread Starter

Road Captain

Joined: Oct 2007

Posts: 741

Likes: 0

From: Charlotte, NC

Well I started with a 28 inter and 68 main. I am down to a 26 inter and 64 main. Just pulled the plugs and they are still black. The bike runs ok in 1st and 2nd but now 3rd and 4th spit and sputter unless WOT. The new addition is take off in 1st requires to bring the rpm's up on launch or the bike will bog like hell and stall out. The mixture screw is 1.5 turns out.

Thanks for your advise Sportsterbob! How do you turn off the acc pump on these?

I looked at http://www.harleyhelp.com/snscarb.html for help and I think the jets are as low as they can go....but I'm still rich as hell....I'm going to mess with the mixture some tomorrow and see what we get.

Aug 17, 2008 | 11:57 AM

#23

SportsterBob

Club Member

Joined: Feb 2008

Posts: 18,575

Likes: 4

From: Norfolk, VA

Quote:

Originally Posted by Mario77746

Look for the accelerator pump plunger on the R/H side of the carb (or the side of the carb facing the front of the bike) . You'll see an actuating arm attached to the throttle shaft that depresses the pump plunger. To the left of that actuating arm is a straight-slot screw with a small spring between the head of the screw and the carb casting. That screw adjusts the throw of the actuating arm. Threading the screw in will reduce the accelerator pump volume. In this case, thread it in slowly until the spring is bound up but don't go "caveman" and torque it down tight enough to crush the spring.

This whole process can be very cumbersome and it requires maximum patience! One thing to remember when dialing in a carb is to NOT make 2-changes at the same time!!!!

Something else to consider.....After shutting of the accelerator pump, don't run the bike down the road just yet because the engine MAY run much leaner. Idle the engine and slowly open the throttle and listen for "popping" and/or "spitting" thru the carb throat.
I had an issue with my accelerator pump not long ago. The pump was dumping in so much fuel that the gas was puddling inside the intake manifold. After shutting off the pump I found the engine was now too lean at off-idle to 1/4 throttle and consequently had to dial-in the mixture screw again.

Last edited by SportsterBob; Aug 17, 2008 at 12:17 PM.

Aug 18, 2008 | 06:50 PM

#24

sfoss

Stage I

Joined: Jan 2008

Posts: 1

Likes: 0

From:

Quote:

Originally Posted by Mario77746

Thanks for the replies all. So far I'm sold on the performance aspect of it. Now, $$$.... How much are we talking to get this up to 80hp / 70tq range? I know everyone is different but a good guesstimate would help. By the way, it's a 76 sporty driveline...Thanks.

pretty sweet chop!! Nice work.

Aug 19, 2008 | 10:06 AM

#25

popstheoldman

Cruiser

Joined: Aug 2008

Posts: 183

Likes: 0

From: indiana

had 60 sporty in 80-86 here is what i did sent cases to michca muclusky had cases machined to match stroker wheels put in xlcr cams bored 20 over 10.5to 1 forged pistons manlly stainless steel valves beefyer valve springs c.c.ed the heads didnt port the heads but was going to later i also took an extra spring from another set of points and doubled it up so they didnt vibrate i was pushing 74c.i i did all work except the cases and the barrels oh also had tillotson carb this bike didnt roll off the line it would launch some of my friend rode it it scared the hell out of them and they refused to ride it again they called it the death machine well hope this helps

ride hard die free
popstheoldman

Aug 19, 2008 | 03:39 PM

#26

popstheoldman

Cruiser

Joined: Aug 2008

Posts: 183

Likes: 0

From: indiana

if you want to know how to cc. the heads correctly contact me will provide the info its really quite easy

Aug 19, 2008 | 07:12 PM

#27

Mario77746

Thread Starter

Road Captain

Joined: Oct 2007

Posts: 741

Likes: 0

From: Charlotte, NC

Thanks again everyone.

Well, I've decided to take a different route for now. I just got a 99 CV carb off of ebay. $107 shipped to my door. The S&S E is just not needed considering my motor is stock. I'll hang on to it incase I build the motor down the road.

Now I have a different question, Will the CV carb bolt up the intake that is currently on the bike with the S&S E Carb? If not, what do I need? An adapter or a new intake?

Thanks.

Aug 28, 2008 | 04:36 AM

#28

sepixlh

Road Master

Joined: Aug 2006

Posts: 751

Likes: 6

From: 500 miles south from Artic Circle

You need adapter ( mikuni-type), a like this ... J&P Cycles ? local dealer ?

Here is one ...by Affe http://www.saunalahti.fi/~affe2/hdlo...705/index.html

Last edited by sepixlh; Aug 28, 2008 at 04:37 AM. Reason: added link

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Aug 28, 2008 | 06:38 AM

#29

Mario77746

Thread Starter

Road Captain

Joined: Oct 2007

Posts: 741

Likes: 0

From: Charlotte, NC

Thanks sepixlh. I picked up a metal press on one. No rubber boot to worry about and the price was not bad either, $37 shipped.

http://cgi.ebay.com/ebaymotors/ws/eB...2BSI%26otn%3D2