Valves on both ends? Yes, sometimes. Dear ATVC: Appreciated your article on the two-stroke power valve but have to laugh when you say the to-stroke engine is designed around using no valves. If it has a reed valve on the intake side and a power valve on the exhaust side, I’d say it is a […] More »

Didn’t need valves but had some anyway. Valves are a fact of like in the four-stroke engine. Intake valves open which allow fuel to enter the combustion chamber, a spark plugs ignites the fuel/ air mix, sending the piston sailing down the cylinder and then exhaust valves open to allow the spent gaseous byproducts of […] More »

Performance gains means tweaking the carb. Dear ATVC: I have a 2004 Honda 400EX and I’m getting a RS3 Yoshimura full system from someone that used it on a 400ex before me and I am not sure how to figure out what jetting I need for it to run good. I would really like to […] More »

Another player has entered the ring. Only last week we talked about street specialists S&S making a splash into the UTV exhaust market. Seems they aren’t alone in the transition. Vance & Hines announced a lineup of exhaust systems for the most popular side-by-side (SxS) UTV offerings on the market. The UTV market in the […] More »

Coming to a trail near you. A few years ago S&S was all over the airwaves with their massive aftermarket engines and exhausts that powered custom choppers. Their latest efforts are focused on the off road space and here are a couple of the goodies they’re releasing: Power Tune Exhaust Incorporating a highly engineered muffler […] More »

The only way to be sure. Dear ATVC: Just bought a brand new 2022 king quad 750. Already got a snorkel kit and radiator relocate on the way. Now something I’m not so familiar with is the exhaust and what the best setup is to keep it running and idling under water. The stock muffler […] More »

Chopper tech arrives to our UTVs. Remember a few years back when ever time you turned on the TV you were greeted by a custom chopper reality show? And powering these pricey one-offs was almost always a big fat S&S Cycle V-Twin? Well it turns out, S&S Cycle has been eyeing up our industry with […] More »