Why is there a â€œdummyâ€ starter gear (a solid ring instead of a gear) on the backside of a drive clutch on some sleds? Isnâ€™t this just extra rotating mass that slows down the acceleration of the engine?
There have been many instances over the years where an engine has been used in various models, some with electric start and some without. Riders, service techs and factory types started to notice the engines ran smoother and how the clutches lasted longer on the electric start sleds. Part of it was due to the added mass of the starter ring gear to the primary. Some riders even started to install the gear on their clutches, even if their sled didnâ€™t have electric start. Think of it as a â€œbalancing gearâ€.
That is what youâ€™re seeing in the dummy ring mounted to the backside of the primary. It is now part of the engine design, so the engine runs smoother and in better balance, either with a starter gear or dummy ring of similar rotating mass. Does it slow down the acceleration? Logically yes, but the benefits far outweigh the alternative. Your engine and primary clutch run smoother and last longer because of it.