I had a friend that developed some kind of gunk in his Vmax radiator several years ago. He had to replace the radiator and was never sure he cleaned it all out of his coolant system and got rid of the bike. No one at the Yamaha shop or anywhere else could figure out what happened. He was an avid Water-Wetter user as are several of my friends.
A couple years later I heard some talk about Water-Wetter causing a problem in seemingly random cases. I found the attached info on a bike forum and saved it.
For what it is worth, I never use Water-Wetter after these instances. A good, clean system with fresh coolant should be ok.
Copy and pasted!
Redline Water Wetter.
This product is supposed to increase the efficiency
of the cooling system.
I don't know if any of you have ever come across this
situation before but I thought I should share the
information I received from the technicians at Red Line
Synthetic Oil Corporation regarding my recent experience
with their Water Wetter product. It seems that if the PH
of your coolant mix is too low the silicates in their
product can come out of solution. In my case this
manifested itself in the form of pea sized gelatinous
globules forming in the coolant mix. These globules
eventually float to the surface forming a thick scum.
Fortunately, as I pre mix my coolant solution, this did
not occur within the radiator. I can only imagine that
flushing the gelatinous scum out of the cooling system
would be quite a tedious chore, to say the least. The
technicians at Redline suggested that the 50/50 mix is
what caused the PH to drop too low and that using a
lower percentage of anti-freeze and the minimum amount
of Water Wetter in the mix should alleviate the problem.
The mix I was using when this occurred was as follows...
1Ω Gallons Prestone Ethylene Glycol Anti-freeze
1Ω Gallons Distilled Water
1 Bottle Redline Water Wetter
(makes 3 to 5 gallons as per instructions)
FYI, changing the concentration of the mix in an effort
to adjust the PH after the fact did not bring the
silicates back into solution. Rather than experiment
with varying solutions I have opted to avoid the problem
altogether by simply not using the Water Wetter product.