Spark Plug question

phatchopper300

phatchopper300

I just wanta ride
I checked the plugs and found Soft, black, sooty, dry-looking deposits which indicate a rich air fuel mixture. I know this has been beat to death but can't find out the exact answer. My question is do I need to change the jetting(still have the stock jets)( I also have vance Hines 2 into 2 and stock air with K&N filter) or just the air/fuel mixture? I have gone thru two different spark plugs and keep getting the same results. Changing the fuel/air mixture doesn't seem to change the rich spark plugs. Or is this due to something else. Any input would help!
 
OZONER BILLY

OZONER BILLY

Active Member
How to adjust your carb and check jetting​



This is a hot topic... posting the thread may help... here's a improved version of what we have told COUNTLESS people.​







To adjust the carb...​





Some educational reading by S&S​





S&S carb adjustments​










S&S Carb Manual​










For my 2 cents...​





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 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 spin the accell pump screw out 1.5 turns​





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 MAY mean you need a larger intermiediate jet. This is a common debate.​





Then re-adjust your idle to about 1,000 RPMs. Too low and it may die. Too high and it will clunk into first gear.​











Now on the plugs... to test run the bike and see if the jets are good. This can also be done before you ever screw with your jets.​





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. The basic idea is white is lean, black is rich. What you are aiming for is a nice cinnamon color to the grounding tip.​





To talk jetting...​





One of the most common problems is...if you are expierencing a cough at highway speed 75mph +/- RPMs at about 2750... cough thru the carb... go up on int. jet.​





To jet the carb... click these links for sniplets out of the how to​



(post #2, 7-8)​

















Of coarse once you change the jets you will need to re-adjust the carb again.​



__________________​




^^My $0.02 not yours^^​







-Chris​



aka Gas Man​











"DEATH SMILES AT ALL OF US --- ALL I CAN DO IS SMILE BACK!" -Al Sensoli​






Originally Posted by Gas Man ​




This is a hot topic... posting the thread may help... here's a improved version of what we have told COUNTLESS people.​







To adjust the carb... ​





Some educational reading by S&S​





S&S carb adjustments​










S&S Carb Manual​










For my 2 cents...​





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 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 spin it out 1.5 turns :confused: ​





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 MAY mean you need a larger intermiediate jet. This is a common debate.​





Then re-adjust your idle to about 1,000 RPMs. Too low and it may die. Too high and it will clunk into first gear.​





​






Now on the plugs... to test run the bike and see if the jets are good. This can also be done before you ever screw with your jets.​





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. The basic idea is white is lean, black is rich. What you are aiming for is a nice cinnamon color to the grounding tip.​





To talk jetting...​





One of the most common problems is...if you are expierencing a cough at highway speed 75mph +/- RPMs at about 2750... cough thru the carb... go up on int. jet.​





To jet the carb... click these links for sniplets out of the how to​



(post #2, 7-8)​

















​





​
 
Last edited:
phatchopper300

phatchopper300

I just wanta ride
Thanks for all the input looks like I may have to get back to basics to start fresh and go from there but thanks for all the input
 
Raywood

Raywood

The Pirate
Staff member
Calendar Participant
Troop Supporter
phatchopper300 said:
I checked the plugs and found Soft, black, sooty, dry-looking deposits which indicate a rich air fuel mixture. I know this has been beat to death but can't find out the exact answer. My question is do I need to change the jetting(still have the stock jets)( I also have vance Hines 2 into 2 and stock air with K&N filter) or just the air/fuel mixture? I have gone thru two different spark plugs and keep getting the same results. Changing the fuel/air mixture doesn't seem to change the rich spark plugs. Or is this due to something else. Any input would help!
Click to expand...
Mike, jetting is a pain when you make changes to the bike. I always rely on a dyno tuner to examine my bikes performance and give me the print out to ensure I'm meeting that so called 13.8 (magic) ratio that all talk about.

But when you are examing your plugs has the bike been running at idle or low speed or high speed? You could jump down one size on the intermediate jet where most of our riding is conducted at and see if that helps. Just remember that the intermediate and main jets work in conjuction to each other so if you change one you may effect the other or have a transition issue at the 2500 rpm range.

Get it dyno tuned with a dyno that has the fuel/air mixture sniffer

:cheers:
 
lee

lee

Well-Known Member
depending on where the blackness is on the plug is an indicator of where the richness is, i.e. at idle or on the fly. Can't quite remember how it goes now but I think if the ring at the top of the plug / top of the threads is black then that says the idle might be rich. If you can't get rid of it it could just be the fuel you are using as modern day fuels have more of a tendency to leave black deposits. Spark plug reading is difficult at best and I'm with Ray - get in on a dyno
 
phatchopper300

phatchopper300

I just wanta ride
Thanks guys yep a dyno is in the near future. Its been running great at idle and the rolling thru 2500 + RPM's. Just didn't like to see the plugs looking all black.
 
You must log in or register to reply here.
Top