At the dealership level, we took the warnings seriously and used "non silicate" coolant. I've been told by multiple industry level people (although it still may be misinformation being passed on) that silicate warnings didn't exist back in "the day" because coolant manufacturers didn't add clean sand to coolant. Silicate was added to keep corrosion from building up to the point of a cooling system failure. I remember discussing this at factory service schools but again, may have been a wives tail. We'll never know.
Some argue the popularity of non ferrous materials in engines and heads caused this switch (cars started appearing with aluminum blocks and/or heads and corrosion became a bigger problem).
I've personally seen mechanical seal failure as service manager that we suspected was caused by coolant. If the same owner had multiple failures and admitting to using "whatever was on sale" then we blamed the coolant...and to a smaller extent the owner. Although i would also argue certain Kawasaki's had much higher waterpump failure rates than the Yamaha, Honda, and Suzukis we sold.
Interesting note...our 1989 MCI coach bus has a Detroit 2 stroke diesel and a warning label CLEARLY warns to use a "silicate free" coolant only!
Not sure why, but would guess it has a mechanical seal type water pump?? It's supercharged and turbocharged so maybe they run into other issues i am not aware of.
Wow, let's find a coolant expert and get some final answers! Where is Mr. Prestone when you need him?
1976 and 1977 GL1000
2012 Yamaha Super Tenere
1972 CB350 twin
A fleet of various Guzzi, Ossa, Honda, Yamaha...