Introduction to Tuning Your Bike!
If you purchased one of the performance products from TJ Brutal Customs, then you will need to tune your machine properly to get the most out of our products. Any time you change the intake or exhaust on a motor you will need to adjust your fuel and air metering to account for the change in air/exhaust flow. The following applies to The Honda Shadows with CV carbs, non-EFI models.
You will need one of our Performance Tuning Kits to properly tune your bike as our kits are assembled specifically to work with our products. Our jet kits are not a "stage" kit as offered by some companies. Our tuning kits are assembled in house to provide you with the exact components you need to tune your bike with our products. “Stage” kits typically do not include the necessary components to tune for our products, or they give you parts that are unnecessary.
Your Performance Tuning Kit will contain pilot jets, main jets and needle shims. If you have a stock jet needle (no notches) You will want to use 2 shims per needle. If you have an aftermarket needle (notches on the needle) you can start at the lowest setting (clip closest to the blunt end of the needle). Many aftermarket kits include a drill bit to drill a hole or enlarge an existing hole in your slide. DO NOT DRILL A HOLE IN YOUR SLIDES!
When installing the jets there is no need to crank them down with much force, a gentle turn to snug them down is all that's required. They are brass so they can break or shear very easily.
There is no magic formula to tune a bike, so yes you may need to pull the carburetor several times and make adjustments. If you are at a higher elevation you will most likely want smaller jets, if you are closer to sea level you will want to use larger jets. Start with the smaller jets and work your way up.
If you are replacing your mix screw with our long handled mix screw, make sure that when removing the stock mix screw you pull the screw, a spring, a metal washer and a rubber O-ring out of the port. Install the new mix screw with the new components only.
The diagram below shows you which tuning parts (jets, needle) affect the different throttle stages. Thus if you are having a lean condition at wide open throttle then you may want to increase the size of your main jet.
Begin by tuning your idle to 1/4 throttle, once the bike starts and gets to 1/4 throttle well, move to the next throttle stage. When tuning it is helpful to use a bit of waterproof grease on the inside of the carb boots and the rear port of the carb to make installation and removal easier. You can reference the videos on our YouTube channel TJBRUTALCUSTOMS for more tuning and carb setup tips!