Honda Used Etylene Glycol based coolant from 1975 through at least 2002 in there 1000- 1500 engines which contain silicates. If You flush the coolant regularly and use distilled water it won' t be a problem. I had much rather put a waterpump on every 100,000 mile (Have yet to have a water pump failure on any GL) than have my coolant passages clogged up and ruin my engine. Buying Honda Coolant is like buying Honda Oil. It's just an overpriced version of what you can buy at a parts store.My little Owner's Manual notes this : "Using coolant with silicate inhibitors may cause premature wear of water pump seals or blockage of radiator passages....." This is an 08 manual though, which is a backwards way of saying that you should use silicate, if I'm reading this correctly ?
About the only time silicate comes into play is if you mix it with harsh tap water. All water pump seals on Honda Cars, Trucks and even most domestic vehicles are made of the same rubber. It's just CYA for Honda. The same as telling you the load limit is 405 pounds, Not to pull a trailer, Not to put more than 5 pounds on a luggage rack and so on. I have almost 1/2 million miles on water cooled Hondas and 0 coolant related failures. Ive seen many many cars with sludged up cooling systems from using extended use coolant. If you followed all of Hondas reccemendations you would be able to get out of the driiveway. I check my tire pressure, oil level, coolant level before each ride. I check all that every few weeks. Honda will scare you right out of riding.Any anti-freeze that is silicate free will work, I buy mine premixed at the Honda dealer, only about $5.00 a qt. so for $20.00 you have the right stuff. A water pump is a lot more expensive than that if you use the wrong stuff. You could buy the stuff at a Honda car dealer and mix it yourself with distilled water and have enough for 2 changes but then you have to store it for a couple of years until your next change.