New Pipes and/or re-jetting the S&S G

[slowrower]

This ones a bit puzzling, from new I had a slight carb sneeze when holding the throttle steady between 2500 & 300rpms. After installing the V&H BR 2-1 pipes, the Carb sneeze was gone (hurray) and no re-jetting. The V&H 2-1 pipes on deceleration would pop loud enough to think someone was shooting at you - always thought this was because it was too rich!! after making adjustments to the carb (same jets still) it would not go away so I re-jetted from .074 (stock) to .076 and .0290 (stock) to .0320 (secondaries). After re-adjusting the carb (setting it to ground zero) out on the road I go and the first thing I noticed as no decel popping. I had installed new plugs when re-jetting and pulled them after my 10 mile ride and they are a nice tan color so it looks like all is well. That said, bad deceleration popping appears to be also related to running lean - anyone else have this? Another puzzler was when running the mixture screw in yes it will stop the motor however running it almost out would not cause the motor to slow down or start to stall. Time to get back on the road its too nice to be inside!

 

[lee]

i thought popping on decel was either lean or an exhaust leak - also remember the adjustment screws are for idlie adjustments - if mixture is out when riding it is the jets
did you get the BR jet kit when you bought the exhaust?
I guess if its running well now who cares about the mixture screw not doing what you expect at idle
I'm not too sure what the accelerator pump screw does but I think it might be something to do with the transfer from inter to main
my exhaust pops a lot but I like it

 

[Gas Man]

The cough from 2500 - 3000 is the transition from int to main. And its usually from a lean condition on the int jet.

My only thing... is why did you jump 2 sizes on the int jet when you changed them?

The decel poping if not from a intake or exhaust leak... is gas burning in the pipe. Did you change the exhaust gaskets when you changed the pipes?

The decel poping with the V&H BR is very common.

 

[slowrower]

i thought popping on decel was either lean or an exhaust leak - also remember the adjustment screws are for idlie adjustments - if mixture is out when riding it is the jets
did you get the BR jet kit when you bought the exhaust?
I guess if its running well now who cares about the mixture screw not doing what you expect at idle
I'm not too sure what the accelerator pump screw does but I think it might be something to do with the transfer from inter to main
my exhaust pops a lot but I like it

Hi Lee, I thought bad popping was from too rich, your right its has to be from too lean. I did get the jets with the exhaust an .076 and .078 with .032 and .034 secondaries. I was reading the instructions on adjusting the mixture and it dies when screwing it in (leaning) and does nothing when running it out (richer). Good point, its now up to the jet so I guess if I out the .078 in it will go rich enough to cause the motor to drop rpms when running it out. It does run much better but I wonder if I should go to the next jet size to be sure. From the guys on the forum, Its better to run rich. Thanks Again

 

[slowrower]

The cough from 2500 - 3000 is the transition from int to main. And its usually from a lean condition on the int jet.

My only thing... is why did you jump 2 sizes on the int jet when you changed them?

The decel poping if not from a intake or exhaust leak... is gas burning in the pipe. Did you change the exhaust gaskets when you changed the pipes?

The decel poping with the V&H BR is very common.

Hey Gas, Vickie sent me the .076 and .078 jets along with the pipes. I did install new exhaust gaskets and used a torque wrench to be sure I was to speck. I also checked the intake and used WD40 to see if I had a leak and do not. The decel popping was real bad before I changed the jets. There is no hesitation at all from idle to 3000+ rpms. My only concern is when screwing the mixture jet all the way out there is no change in rpms, so I was wondering if I should put in the .078. Thanks Again!

 

[lee]

listen to Gas man he knows what he is talking about far more than I do - Bob from Triple X puts a 78 main jet in as standard - you're right in what you say it is better to run rich as you can burn valves out etc by too much heat running lean

 

[slowrower]

listen to Gas man he knows what he is talking about far more than I do - Bob from Triple X puts a 78 main jet in as standard - you're right in what you say it is better to run rich as you can burn valves out etc by too much heat running lean

Thanks Lee, I am going to put the 78 in tonight.

 

[lee]

S & S Carb Tuning Tips MILLER'S CUSTOM PARTS S. DAYTONA, FL (386) 761-0858

Have a look at this as well - there are also other tuning links on here somewhere - do a search

 

[Gas Man]

listen to Gas man he knows what he is talking about far more than I do - Bob from Triple X puts a 78 main jet in as standard - you're right in what you say it is better to run rich as you can burn valves out etc by too much heat running lean

I don't know about all that Lee but thanks.

Just in case you havne't saw this... I will quote in some info I have conpiled to help everybody adjust their carb and check their plugs.

on the adjustments... will paste in a layout on how to adjust the carb

Also include S&S adjustments
S&S Shorty Carburetor Adjustments

S&S Carb Manual
http://www.sscycle.com/modules/instruction/uploads/51-1012.pdf

Exactly... if you can't adjust it with the accel pump then you need to go bigger on the int jet.

You can use the "remove your carb" thread to help get to it... look at post #1,2,7,8 to aid you in getting to your jets. No need to remove the carb... just have to drop the bowl.

To adjust the carb... with the bike warm...
(in=clockwise/out=counter)

if your idle is low... turn it up a bit...

now spin in the accel pump screw till it seats. Now spin it out 1.5 turns

now spin in your fuel/air mix screw till the motor sounds like it wants to die

now spin it back out counting 1/4 turns. Do it slowly to give the motor/carb time to adjust. Do this till the motor sound like it wants to die on this end. Now you have counted those turns and you have say 2.5 turns. Spin it back in 1.25 turns. Or middle to almost dead on each end.

Now adjust your idle to 1,000 rpms on the tach.

Now with a few quick stabs at the throttle see if the rpms come up fast like you would think or if it kinda hesitates then takes off. If it does hesitate then spin the accel pump out another 1/4 turn and repeat till you get what sounds good.

If that don't fix the sneeze... you can spin out the accel pump a bit more... but anything over 2.5 turns means you need a larger intermiediate jet.

Now on the plugs... to test run the bike and see if the jets are good.

Check or replace plugs.

run the bike but keep the RPMS below 2500... then don't let it idle and kill the motor, check the plugs. That is to help check the int jet.

Then take it out and run it hard... keep the RPMs up and romp on it... then on a striaght patch of road with the RPMs up high (over 3k, or even higher) kill the motor with the OFF switch. Pull the plugs and check. that is to test the main jet.

The idea here is that your int jet runs from idle to about 2750. Then the main kicks in from there out. That's why we say your run mainly on your int jet. main is only for romps.

Use this GUIDE to read your spark plugs.

 

[Gas Man]

match by the flange... that's a good one... could you use a lighter instead?

 

[Gas Man]

Could use a house lighter thing, like you use to light the grill or the wife uses to light candles... aka long stem