Clutch The KTM 250 EXC-F employs the KTM-developed DDS clutch (damped diaphragm steel) with a wear-free steel basket and extremely heat resistant clutch plates and new, nitrated steel liners. This clever design employs a diaphragm spring instead of the usual coil springs, making for considerably easier clutch action.
The difference between active and passive solar water heating systems is that active systems have circulating pumps and controls, while passive systems do not. Although passive systems are usually not as expensive as active systems and can last longer, they are generally less eficient.
Thatâs a much better deal than a solar thermal system that produces only 63% as much hot water â even if you do have to buy a new heat-pump water heater in 12 or 14 years. (Trust me â if you have a solar hot water system, you'll have to invest in maintenance and replace a few parts over time, too.)