Running lean some poppine at idle

Kits like cobra or sigmajet are great for tweaking, judge your present performance first and determine if you're in the ballpark; Is it responsive throughout the powerband? How's your exhaust looking? If the pipes are showing signs of getting too hot (chrome bluing, exhaust tips chalky white=too lean, tips black=rich).
On to the spark plugs. "Reading" a plug gives an excellent picture; after a somewhat aggressive run with out too much idling pull the plug and have a look at the porclean insulator just above the electrode gap. Best is a nice even cocoa brown. Black=rich, white=lean. I would suggest zeroing in thoroughly, then consider going above and beyond if you wish.

Sounds like you need to take it to a shop that kinda knows what they are doing. If they have problems they can call cobra themselves. As a shop the aftermarket companies are usually pretty good about helping out since most of their product is sold or installed in aftermarket shops. With that being said. I would start by dropping the clips up one notch and see how that works. By sliding it up one notch it should run a little leaner . If it's better but doesn't cure the problem then go up one more. If it does clear up the black smoke then there you go. Generally cobra will tell you in the directions what common jets to install. They even have a section for higher elevations as well. If not in the directions they usually do on their website. Hope this helps a little.

I’m happy to assist further over the phone at https://www.6ya.com/expert/robert_5bac37c3cb991fdb

Pipes turn blue because it's running lean.Not enough gas and TOO much air.Idle mixture screw needs attention.Turn in till ingine starts to die and back out to fasted idle.Then adjust Idle speed with the screw on cable at carb.

Is engine running OK? If so and the muffler is an economy muffler, take it back to where you had it installed and see what they will do for you. If the engine IS NOT running right , it may be running to lean and tat causes an overly hot exhaust system. You may need to have the engine diagnosed for performance issues.

You can try driving the bike after the install. After you change the exhaust it will run lean. You may want to coat the inside of the mufflers with an anti blu-ing agent or your headers will discolor. If when test driving you notice the bike has developed a flat spot in the acceleration curve you will want to re-jet the carburetors. The easiest way is to buy a jet kit from Cobra, Dyna-jet,etc.($80-$100). Other wise you can just buy several sets of larger jets and change them out till you are happy with the way it runs. Most people that change the mufflers and put in a jet kit, also install a K&N air filter .
More air flow + fuel flow = more exhaust flow (more power)

It sounds rich to me try turning the "L" needle CW a little. CAUTION CW is leaner, to lean will destroy your saw. Adding the air cleaner leans out the mixture. Adjusting it with the air filter off can cause a run lean condition when installed.
Carburetor Adjustment by Madsens.com
http://www.madsens1.com/saw%20carb%20tune.htm

• CW is leaner; to lean will destroy the saw. If over tightened closed (CW) the adjustment screw faces are easily marred; marred adjustments are difficult to impossible to set properly.
• Clean the air filter; adjusting with a dirty filter can cause a run lean condition once cleaned and the saw run.
• Clean the spark arrestor and muffler; if the saw cannot exhale it cannot inhale.
• There are 2 wav (sound - idle & full - may not be highlighted) files that I find most helpful, I think you will too.

If you have more questions or need additional help please reply below and I will get back to you. Good Luck. HTH
Lou
Thank You for using FixYa.

they are not stock, just call your local Honda shop ask for the parts desk, tell them what you want. They will help you get the right carb parts. without vacuume gauges you might just pay for the work to be done,

Hello Kieth:
If you must choke it for it to run it is lean. To lean for to long will ruin your saw. Clean the air filter. Stihl more than any other saw plugs up mufflers (if it cannot exhale it cannot inhale). Remove clean and reinstall the muffler and spark arrestor, if no better adjusting the needle valves may correct it.
http://www.stihlusa.com/stihl_ownersmanuals/STIHL028_with_safety_manual.pdf
Page 39 gives an initial setting for the "H" and "L" needles. I always wonder what happened to cause this. I fear constant tweaking of the carburetor may hide a bigger problem until the saw is destroyed. Adjust for performance as follows:
Carburetor Adjustment by Madsens.com
http://www.madsens1.com/saw%20carb%20tune.htm

• CW is leaner; to lean will destroy the saw. If over tightened closed (CW) the adjustment screw faces are easily marred; marred adjustments are difficult to impossible to set properly.
• Clean the air filter; adjusting with a dirty filter can cause a run lean condition once cleaned and the saw run.
• Clean the spark arrestor and muffler; if the saw cannot exhale it cannot inhale.
• There are 2 wav (sound - idle & full - may not be highlighted) files that I find most helpful, I think you will too.

If you have more questions or need additional help please reply below and I will get back to you. Thank you for using FixYa and Good Luck. HTH
Lou

hi this might help,by fitting an after market exhaust system you will probably have leaned out the fuel air ratio in the carb(less back pressure in the exhaust system)you will need to have the carb rejetted to suit the exhaust modification,if you keep running the bike as it is you will inevitably seize the motor as it is running way to lean .cheers

have you installed after market open pipes? with fuel injection, the computer module can adjust to a certain point, then you need an afetermarket module. the fuel is to lean, which on a carb model you would adjust the jets. extra hot pipes most likely cause is to lean a fuel mixture, with most harleys caused by no muffler exhaust. this will also explain the high idle.