My f35 Pedrick has 873 hrs in it - 1999. Low I think. Returning from the Delta Ditch Run race I panicked over the thought of my two belts - boat is 1999 and I’ve had her since. 2016. Same belts! Tomorrow I’m replacing the crank and waterpump belts. What’s the usual replacement period? I’ll be easier after tomorrow!
My approach has been to inspect periodically and replace when deterioration or dusting is noted. Maybe a 5 year cycle as a baseline.
I have a serpentine belt on the alt/fresh water circuit which I look at frequently and is about due after 5 years. The raw water pump belt has been in place for six years and still looks good. I carry spares on board for both. Change out is straightforward on my boat.
One thing to note about these belts: the alternator drive belt needs to be tight, but the water pump belt should be loose. It doesn’t need much torque transmission to do its job, and can function just fine with a slack belt. If you tighten it like the alternator belt, it will put too much force on shaft, which dramatically reduces the life of the drive shaft seal.
