Basic Performance Tuning, at least where to start… The first thing you should do to improve performance on a stock HD is to open her up so she can BREATHE. You can do this for 10s of dollars, not hundreds. This is cheap, easy and not overly technical AND you don’t need any special tools.

Stock pipes and air cleaners choke the bike. You can drill the stock baffles or pony up some cash and buy upgraded or aftermarket performance pipes/slip on mufflers for increased air flow. As for the air cleaner, buy a screaming eagle filter element, which won’t require and cover changes or spend some cash on a K&N. Once those are done, you need to adjust the carb and possibly re-jet.

Adjusting the carb is not hard so don’t be spooked. Not only will you feel better doing it yourself, but you’ll learn more about YOUR bike.

A stock (CV) carb that has not been tinkered with will have a “tube” off of the fuel bowl that has a metal cap or plug in the top, under that is where the idle mixture screw is located. You have to drill a small hole in the plug to remove it, but be very careful not to go too deep. Wrap some tape around the drill bit about an 8th inch from the tip to make a sort of stop. Drill, then pry the plug out – could start a screw into the hole and pull it out with pliers. You’ll have to remove the carb from the bike to do this, but not all the throttle cables etc…just enough to be able to maneuver the carb enough to get to the idle screw cover. Once you have the cap out, turn the mixture screw IN until it barely seats. Now back it OUT 2 complete turns. Reinstall everything, including air cleaner assembly. Start the bike and allow it to reach normal operating temperature. If the bike won’t idle, kick it up a hair using the idle stop adjusting screw located near where the throttle cable attaches to the carb. With the engine idling just under 1000rpms, turn the screw in slowly until the engine begins to die off and sputter. Then, back it out until you just start to run smooth – and give it one more 8th of a turn (OUT). Crack the throttle and see how she responds. If it responds good and no popping, you’re good. If it pops through the carb, back it out another 8th of a turn. Now take her out for a ride. If it pops through the carb, back it out another 8th, but you should not be more than 3 full turns OUT on the adjustment screw in the end. If you are, and are still running lean, experiencing popping through the carb, you need to re-jet. Go up a jet and go through the carb adjustment sequence again.

If you don’t already know how to, then LEARN to read your spark plugs. This tells you so much about your engine condition and tune. The porcelain around the electrode will be golden brown on a properly tuned bike. If it’s black and fluffy, your fuel/air mixture is too rich. Typically in this case, you will have performance issues with your bike being sluggish and will be accompanied by black smoke from your pipes. You may experience starting issues or she might just cut out on you due to fouled plugs. If the plugs are white, then your mixture is too lean, and will more than likely be popping through the carb. Plugs that are shiny black means you’re burning oil – usually this will produce white smoke from your exhaust. Time to do a top end job, pistons and rings. A personal note – do NOT buy or use HD, screamin eagle or splitfire plugs, they suck for HDs and are overpriced at that. Use Champ or Autolite…trust me!