imported post
I was asked about the usage of Evans on another thread so I decided to start a new one.
To those who haven't heard of this stuff, it's a water free coolant. The company takes proplyene glycol and ethelyne glycol and mixes it together. It is non-toxic and has a boiling point of 375deg F. with
no pressure on the system. It is considered to be a 'lifetime' coolant with an expected life of 250000 miles+. With little or no pressure being used, the instance ofhose failure, radiator failure, head gasket failure, pump failure are greatly reduced if not eliminated altogether.
Since it doesn't use water, corrosion and scaling are no longer a problem. The NPG+ was developed to be used in exsisting systems without modification to the pump or radiator. The formula is safe for all engines. The original NPG was a bit too thick for a stock pump to move correctly. It is still used in race cars and engines with modifications to the pump and radiator.
While you can use NPG+ in a zero pressure enviroment, Evans suggested running a 4-7lb radiator cap(
available at NAPA/O'Reilly autoparts stores)to reduce having the system "breathe" in and out and possibly inducing atmospheric moisture into the coolant. Water is considered to be a contaminant. Whenyou go to use Evans for the first time, you need to completely flush out the old coolant and water first. They sell a prep. fluid that absorbs any residual moisture. This is then discarded per EPA instructions. I drained the old coolant out and then used tap water to continue to flush the system. I was suprised at the scale that came out as I did this. After running about 5-6 gallons through, I then re-filled with tap water and warmed up the bike. I then drained, rinsed and repeated. More scale came out. Finally when I was satisfied that I'd gotten as much crud out as possible, I used half of the prep fluid, warmed up the bike and let it run for a couple of minutes per instructions provided with the prep fluid. I repeated this process with the first half of the prep.I thendrained that out and used the second half and repeated the process.
I am now satisfied that I've removed all of the contaminants and filled the bike with the NPG+. I continue to use the overflow tank. When the bike is cold, the level is halfway between low and full. When the bike is hot to the point of the fan running, the level in the tank rises to full and no more. I am using the standard thermostat as no modification is needed in that area.
I was concerned about the "breathing" that the overflow tank was doing and possibly breathing in that nasty atmospheric moisture so I wondered what I could do to seal the system off from outside air. I knew I couldn't just plug up the overflow tank as that would surely not be smart(tank go BOOM

)under pressure. So, it dawned on me to use a bladder attached to the overflow tube. What to use?? I ended up using a "punch-ball" balloon attached to the overflow tube. This balloon rests in a nest of foam rubber on the right hand side of the faux tank. I attached it to the tube when the bike was cold. Suprisingly, when the bike is as hot as it's going to get the balloon hardly inflates at all. (I carry a spare in the trunk and let the grandbaby play with the other one:grinner
The NPG+ is $28.00 a gallon and the prep is $22.00. This may sound high but considering that you only have to do it once it balances out. Plus the aspect of not having to worry about boil over or catastrophic failure due to a hose blowing out helps the piece of mind. If you should have a failure on the road, you can replace the lost fluid with Sierra or Prestone low-tox. You just need to drain it out within 30 days per Evan's instructions.
My wife and I rode in 90 deg F. weather yesterday in town and out and the bike ran well and no temp issues with the engine.
That's it for now.
Hobie