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1,556 Posts
Discussion Starter · #1 ·
I changed out the coolant last Saturday. It took 2 hours because of the number of steps involved to clean out the old coolant's additive package and scavenge out the water. But, now my reservoir bottle glows purple.

Effects noted since changing the coolant and going 90 miles:
BlackRune runs the same,
women think I am more studly: ... type=large
guys buy me drinks
I have lost 3 pounds
my boss wants to give me a raise


Swamp Rat
6,991 Posts
I was wondering when someone would finely do the deed.
I have all the ingredients unopened, but neatly stacked, along with the recipe just waiting for me to get the time.

Quite frankly I’d be more impressed if :beer8: girls bought you drinks.

1,556 Posts
Discussion Starter · #4 ·
Take care when removing the radiator cover. The LEFT side comes off with the chrome grillwork.

The effect of putting forced hot air in the radiator filler hole was spectacular. Be sure to do it when your buddy is sitting on the left side near the drain hole. You will get him real good :oops:

ken (31,000 miles and holding - due to weather)

1,556 Posts
Discussion Starter · #6 ·
while you have the radiator cover off, go ahead and flush your hydraulic clutch. You can do that in August after you do the Evans in July :wink: You cant get to the bleeder nipple with the shroud on. It is the hose that is terminated in the bottom of the radiator. A bleed screw is on the end.


Swamp Rat
6,991 Posts
Ken I am flushing the system at this moment and that just may be the limit of my mechanical abilities.
Do you know if the service manual provides instructions on how to flush the hydraulic clutch?

AND What the hell is a clutch?

1,556 Posts
Discussion Starter · #8 ·
Oh SiteData,
Yes, the clutch bleeding procedure is in the svc manual.

Isnt your Rune 1 year old? And, is the site glass dark or the color of Jim Beam? Then, since you have the cover off I would do it. It is a pain enough to get the radiator cover off. Dont you have a lift?
It sure helps having the bike high enough off the ground that you can put a milking stool under Her and run a rubber hose from the nipple to a bottle.

Do you have a vacuum cleaner that you can set to "blow" air? You could use that with a hose nipple to blast out the radiator during the final water rinse phase before putting in the Evans Prep fluid.


Swamp Rat
6,991 Posts
I took a proton of a heavy box that once contained Lamb Shanks and devised a reducer which I attached to my leaf blower;
dammed near blew the RnneSki side covers off.

I’m ready for the “Prep” stage now and will again hit it with a Lamb Shank.

I have a lift but didn’t need it. I will check the manual this evening and make a decision as to my perception of difficulty.
However, I will take your advice and if I have concerns about my competency I’ll run it up to the shop before I replace the covers.

Oh, my Rune will be two years old in 25 days and I just passed 8,059 miles; see I am a wimp!

Swamp Rat
6,991 Posts
I’m almost done.

I’m almost done.

I’ve Super Juiced it, drained the breather, changed the oil in the final drive, changed the engine oil and replaced the filter.

Tomorrow I’ll run the hell out of it and if nothing falls off I’ll reinstall the shinny things and go take a take a nap.

Thanks to all who guided me through.

1,556 Posts
Discussion Starter · #12 ·
Let me know if you notice that your cooling fans come on a bit more often. I have noticed this.

This means the Evans is making the engine run a bit hotter than the 50:50 mix, which was to be expected.

Hotter is not bad if you don't have steam. And hotter is not bad since we are running synthetic oil.

I posted previously that I got better gas mileage on my recent trip to VA and back to SC (900 miles). Did you read on the Evans website that engines run more efficiently if they are allowed to run hotter? The problem with going "hotter" on a 50:50 mix is that the water turns to steam etc. The Evans is not doing that. But, racers know that running their electric fans is a source of "parasitic loss" of HP -- because you have to supply that power (70 watts in our case) by turning the alternator.

I would like to find out if there are times during the hot summer that the fans are running while the bike is moving. That would be unnecessary.

So, I checked out the Service Manual and traced the schematic of the fans (foldout on page 22-1). It appears the fans get their "run" command from the engine computer ECM (engine control module). The coolant temperature gizmo, the ECT sensor-- aka engine coolant temperature sensor, page 20-16 to 20-18 in the service manual-- is mounted on the left cylinder head. It is a variable resistor that goes to less resistance the hotter it gets. It connects into the ECM, not the fan relay.

So, just swapping out the sensor for one that has a different resistance curve wont accomplish my goal of raising the fan turn on temperature by 20 degrees without messing with the engine mapping.

The right way would be to find out how to reprogram the ECM (engine control module) to raise the fan turn on temp.
Another possible way that is not elegant, is to put a relay in series with the fuse that feeds the fans, with a switch or a solid state relay that gets its "turn off the fans" command from the enging speed sensor.
The McGyver way is to just pull the fuse. The coolant is not going to boil while riding normally. Perhaps a parade situation would warrant putting the fuse back in.

The bottom line thus far is that we dont have water in our cooling systems any more. The engine wont boil over, and the internal system cooling pressure is going to be just a few PSI, even with the OEM radiator cap, because the propylene glycol does not expand as much as 50:50 does. And, check out your gas mileage. See if it is any better. My estimate of +20 degrees running temperature means nothing to the engine. Remember, it was horsepower de-tuned because of overheating. Overheating is the runaway condition when steam begins to be generated on the hottest inner surfaces of the engine. We dont have steam no more, and I want to recover that potential Horse Power!!!!!

I wish there was an indicator light that comes on when the fans do. Maybe a vampire tap with a LED could be a temporary jig to see how much they are running. I know they are off on the interstate doing 85+ because every time I pulled in to gas up, the fans did not turn on until after I got to the pump and let her idle for a minute.

Ken (32,000 miles)

Swamp Rat
6,991 Posts
I find it interesting, somewhat comforting and a bit distressing to learn your fan is coming on more frequent, I am having the same experience.

Interesting - because I assumed the engine would run cooler.
Comforting - because I thought that I may have screwed up with the change-over
Distressing - because I assumed the engine would run cooler causing less wear.

As it turned out during the change-over our weather was less than advertised by the State Chamber of Commerce and so, because of the rain, I was able to allow the radiator to completely dry out for three days after the Prep Treatment and final flush with NPG+. I am reasonable certain there was virtually no moisture left.

Before I replaced the cowling I ran the Rune at 95 mph for about twelve miles and returned to check the fluid in the reservoir, which was on high level line. It was upon my return that I noticed the fan was running; this had not occurred before under exact circumstance.

I read your prognosis with interest and bewilderment; the subject matter is not within my limited scope of expertise. I grew up in a depressed, defunct coal mining town in Western Pennsylvania where my peers longed for careers as grease monkeys. As a kid I refused to learn how to change a tire because I was afraid that would become my lot in life.

Before I consider anything that may affect the mapping, reprogramming the ECM to accept a higher temperature, relay fuse or fuse elimination I’ll dump the Super Juice and fill it up with GatorAid.

I am going to defer, to some degree, to you benevolent guidance. The some degree proviso relates to recommendations above and beyond my aptitude.

You Said; “The bottom line thus far is that we don’t have water in our cooling systems any more. The engine won’t boil over, and the internal system cooling pressure is going to be just a few PSI, even with the OEM radiator cap, because the propylene glycol does not expand as much as 50:50 does. And, check out your gas mileage. See if it is any better. My estimate of +20 degrees running temperature means nothing to the engine. Remember, it was horsepower de-tuned because of overheating. Overheating is the runaway condition when steam begins to be generated on the hottest inner surfaces of the engine. We don’t have steam no more”, and if so I’ll leave things as they are.

To date the 12 mile run is the only time I’ve had the Rune on the road and so I can’t speak to mpg or experience with performance. The only thing I noticed was that the fan came on in a circumstance that had not occurred before.

I’ll be interested to hear reports from the other nimwads that made the change-over.

1,556 Posts
Discussion Starter · #14 ·
You wont have any additional engine wear because the engine is running a few degrees hotter. nada zilch. hotter is good for the performance of the engine. Nothing will make the engine run cooler than water -- in the narrow range of performance that water has for transporting heat. The
Rune was mapped for water, from what I can gather, the main effect of this mapping in the range of temperature where the fans come on is just that... to turn on the fans.
Oh, if you ran the Rune without the radiator shroud, it will give you a false sense of despair. You got to have that shroud in place. You should notice an improvement with it properly on. I saw the same thing when I was running the water flush and the prep fluid.

The metal of the engine could not give a rat's ass about being 20 (my estimate) degrees warmer. But, you better believe that if 50:50 was running 20 degrees warmer not only would the fans be running, but the engine would be getting less cooling because of nucleate boiling and waterpump cavitation and would be getting ready to go Chernobyl on you.

For now, I am going to just go on with life and let the fans run more often. I dont think they will wear out anytime soon. It is easier to replace a fan than a water pump. And that was the objective, to protect the cooling system from itself, I mean, from the bad effects of old technology. Remember too that aircraft engines are now running Evans instead of 50:50 and antique cars are as well. Our Runes are somewhere in between those two extremes of mechanical wonderfullness.

Swamp Rat
6,991 Posts
Ken it confuses me when people use reason and common sense to explain an issue; please be a little less eloquent in the future.

What is this purple deal?

My Super Juice is colorless, feels warm on my skin and has the consistency of thin syrup. Did we get the same brew, EVANS NPG+, Waterless Engine Coolant; black container with a green label.

It doesn’t taste too bad once you get accustom to the ringing in your ears and blurred vision.

1,556 Posts
Discussion Starter · #17 ·
The coolant has a purple tinge to it. I noticed that it is more purple with some mileage on it.

You need to mix the coolant if you are going to drink it! Probably something with lots of alcohol, like everclear or Vodka.

It does feel silky-smooth on the skin. I wonder if that is why this stuff is in lots of body lotions!

Yes we have the same stuff.


1,556 Posts
Discussion Starter · #18 ·
Doing more research I have found that, yes, propylene glycol will run a bit hotter.

From a wing website: ... nformation


Check out EVANS waterless coolent systems. Works WONDERFULLY well and is PRESSURELESS and WON’T BOIL OVER. Not to mention you take that nasty oxidizing water out of your 14,000 dollar machine! Go HERE for how to convert your wing to this system. Note: the temperature gauge will read HOTTER after the change over due to more heat being transferred. This is NOT a bad thing
---------------------------------------------- ... pl?file=64

will england :: motorcycle notes and tips
navigation:: will / outdoors / motorcycle / notes /

Evans NPG Coolant


Evans NPG Coolant

After speaking with David Haggard who had used the Evans NPG Coolant
successfully on his GoldWing during last year's Waltz Across Texas in
110 degree heat, I decided to move to this product. I had to replace
the coolant anyway while fixing my radiator leak so, this was the time
to do it. At the bottom of this report is an email exchange I had with
David that convinced me to try the NPG Coolant. Here are some links of
David's that explain how to convert your current bike to this system. ... rt2npg.htm and some

more info on the coolant at ... onvert.htm.

My results? The NPG coolant works great! While moving, the bike's
thermometer stayed lower than normal. While stopped, it would climb a
bit higher than normal but then stop and stay well below the red danger
area. I had tested this coolant in the cooler climate of Washington but
wanted to try it out in the hot desert areas too. I can't say for sure
but I did seem to feel I had more power than before at certain speeds.
No scientific data to back that up, though. Just my before and after
totally unbiased feelings. ;-)

Joe Zulaski, 2001

=== also ====
Here's a rather long treatise on my experience with Evans NPG. Feel
free to pass it on to the nay-sayers.

Operating temperature--
My Wing (with Evans NPG) runs with its temperature gauge at the exact
same point as it did with water/EG mix. It tends to run warmer around
town, but the fans don't cycle any more often than they did with water.
Your engine can safely run at over 300 degrees (according to General
Motors, anyway). The primary reason to be concerned about operating
temperature with water mix is boilover. You simply can't keep the
water/glycol mix in the engine when the temperatures go over 265 or so.
When the coolant boils, it pushes itself out through the overflow. What
replaces it? Steam and/or air. And THAT is when your engine is damaged.
When no liquid coolant is in contact with the engine's metal.
Evans NPG boils at 370 degrees. As long as it is circulating, it
stays in contact with the engine's metal surfaces and cools the engine.
Water Wetter works on ONE of the same principles as Evans NPG. Water
Wetter reduces the coolant's surface tension, so that steam bubbles
don't adhere to the metal in the hottest spots of the engine (nucleate
boiling). However, Water Wetter does not increase the boiling point of
the coolant. And water/EG with Water Wetter STILL has more surface
tension than Evans NPG.
In fact, the ONLY thing that increases the coolant's boiling point
with regular water/EG coolant is the pressure cap. As you know, if it
fails, you've lost your coolant. Then you're on the side of the road.

Heat capacity--
One of the biggest objections to Evans coolant is "it can't carry
away heat as efficiently as water can." That's true. But the other
question that nobody asks is, "How much heat needs to be carried away?"
The truth is, water/EG coolant can carry a LOT more heat than the
engine can produce, IF it stays in the system. Well, Evans NPG can also
carry a lot more heat than the engine can produce. Certainly, it's not
as efficient as water/EG mix. But it is PLENTY efficient ENOUGH. There's
a lot of heat comes out of an engine, but not as much as everybody

Cavitation in the pump--
Hasn't been a problem for me. In fact, Evans warns car owners NOT to
put underdrive pulley systems on their cars with Evans coolant. For high
performance applications, they want the pump to turn FASTER if possible.
Does that sound like a cavitation problem?

Yes, Evans coolant is much more viscous than water/EG mix. But again,
for me it hasn't been a problem. I run it in my cages, and the stuff
looks like syrup in the radiator when the temperature drops below zero.
But that has never been a problem. No overheating under any conditions.
And apparently it isn't so thick that it doesn't flow plenty good

What leaking? By the way, water molecules and ethylene glycol
molecules are both considerably smaller than propylene glycol molecules.
I've never seen a leak in any of my vehicles running Evans NPG.
What makes your cooling system leak is PRESSURE. Once the water gets
hot and steam pressure builds up, you've got up to 16 psi of pressure
inside the hoses, radiator, and block of your engine. That pressure
wants to push liquid out of any little pinhole it can find. It's that
pressure that bursts hoses, splits radiator seams, and blows through
head gaskets.
Evans NPG, on the other hand, doesn't build pressure. I run a
zero-pressure cap on all my vehicles. The coolant free-flows to the
overflow. The only reason you need an overflow at all is because the
coolant expands when heated, like most every other substance on earth.
So it expands into the overflow. The main purpose of the overflow is to
prevent air from entering the cooling system.
With no pressure to push the coolant out, it stays where you want
it-- in the engine.

High-performance engines--
For ultra high performance engines, like the engine I'm building for
my Firebird, you DO need more cooling capacity. For my Firebird, that
means a high-flow pump and radiator. That's a 90 gallon per minute pump
paired with a dual-row, 1-inch tube aluminum radiator.
The only reason that is needed is for high-power bursts. If I
promised never to put my foot in it (Yeah, right!) then I could easily
run the standard water pump and radiator.
And despite what we all like to think, our motorcycles are high
performance engines, but NOT ultra-high performance. They don't
generally need more cooling capacity.

The question is asked (not just here), "the ones on the list who were
'very satisfied with the results', how many more are very satisfied with
the results of using plain old water and ethylene glycol? Working with
propylene glycol on a daily basis as I do, and witnessing it's use in
internal combustion engines over 30 years ago, there's no way I would
use it in my m/c engine."
That's a statement typical of people who are stuck in what I call a
"water bias." We tend to think that the only thing we can use for engine
cooling is water. Why? Because that's what we've always used. Most of
the people I talk to are automatically opposed to using Evans NPG simply
because it doesn't use water. And without water, they reason, you can't
cool the engine enough.
That simply is not true.
There are vehicles out there that shouldn't use Evans NPG coolant
without modifications. I converted a Cadillac that had a funky bypass
system in its design. Too much coolant would bypass and not enough would
go through the radiator. There was no way to cut back or eliminate the
bypass in that design. So that engine needed the extra efficiency that
water coolant offers. I should mention, though, that that particular
model of car (the old "big" Cadillac Seville) is known for having
cooling problems.
There seems to be some evidence that GL1200 Gold Wings shouldn't use
Evans coolant. I don't know why. Maybe they have too small a radiator
for the engine. But I suspect that the problems may go away with a new
radiator that isn't corroded up. I haven't been able to investigate it.
I've never owned a GL1200.
That said, let me put it to you this way. All it took for me to be
VERY dissatisfied with "plain old water and ethylene glycol" was the
first time I had a radiator hose burst 100 miles from nowhere on a hot
Texas day. As I walked toward the nearest exit, and hopefully held my
thumb out for a ride, I thought to myself that there HAD to be a better
way to cool an engine. (This was in a time BCP, before cell phones.)
It took over twenty years, but I found Evans NPG, and I haven't
looked back.

And speaking of those GL1200's--
If their real problem is old cooling systems, then that means they
have corrosion in them. I don't car how often your flush and change your
cooling system. If you're running water/EG mix, your cooling system is
slowly corroding. Water is an active corrosive substance, and it loves
to eat iron, steel, copper, and aluminum.
Evans NPG, though, is used without water. It's a "chemically neutral"
substance as far as internal engine parts are concerned. No water. No
Plus, Evans NPG is primarily propylene glycol. Drink it if you want
to. It won't hurt you. Maybe give you a case of the runs, but that's
about all.

The "I work with propylene glycol and I see what it does" argument--
Can you use plain propylene glycol (PPG), or Sierra coolant, instead?
If you run straight PPG or Sierra coolant in your engine, it will
gradually break down into a nasty goo that will really mess things up.
Those who object to using PPG in an engine are talking about this.
One of Evans' patents is on their inhibiting system that prevents
this breakdown. And apparently it doesn't gradually go bad like the
inhibitors in regular antifreeze. Evans has engines running over 300,000
miles on this stuff with no coolant change.
The only objection I have to it is that their pretty purple coloring
turns brown in just a few miles. I'd like to see them come up with a
color that doesn't change. But if that's the only problem, who cares?

"On the road" observations--
At the CMA National Rally in Carthage, MO last year, the temps were
hovering around 104 degrees. My Wing idled its way around the slow race,
the cones, and all those other low-speed bike games, and the gauge never
climbed above the point where the fans kick on. The fans were more than
adequate to keep her cool. Other bikes running regular water/EG coolant,
and the air-cooled machines, had to be shut down regularly so they could
cool off.

On last year's Waltz Across Texas Rally, the outdoor temperature was
110 degrees in the Big Bend area of Texas. The temperature gauge on the
Wing settled itself halfway between its "normal" position and the point
where the fans kick on. The gauge sat there and didn't waver for 400
miles, when the outdoor temperature finally began to drop. That was 400
miles of hard, twisty roads up the Rio Grande, at speeds varying from 25
to 75 mph; and Interstate highways at 75 mph.
The Beemers at the fuel stop at Palisade TX sounded and smelled like
they were on fire. My Wing sat there cool as could be. No fuel pinging
on acceleration. In fact, one of Evans' and GM's claims seemed to be
borne out-- the hotter the day got and the higher the temp gauge climbed
(up to where it settled in), the better the engine ran. GM testing has
shown that elevated operating temperature improve both emissions and
performance, if the engine is tuned for it and fuel octane is

Last summer we drove across Kansas in my wife's Cadillac Sedan
DeVille, running Evans coolant. The bank signs in Great Bend were
reading between 106 and 115 degrees. The Caddy's electronic thermometer
was reading 113.
This car has a computer that will read out any engine operating
parameter you want. Out of curiosity, I set it to read out coolant
temperature. We spent two hours in Great Bend, idling around town,
sitting at stop lights, with the A/C running. There were steam plumes
all around town as cars blew their lids. But that Caddy's temperature
readout varied between 103 and 106 degrees Celsius. That's between 217
and 222 degrees F. That's "normal" operating temperature for that car.
Once we rolled out on the highway, the temp settled in at 103 (217). And
the kicker? At any time I wanted, I could have raised the hood and
screwed off the radiator cap, and it wouldn't blow or boil out. NO

As far as I'm concerned, you can't ask for better testimonials.

Trying it for yourself--
You're talking about an ST1100, right? I don't know the cooling
system capacity of an ST1100. I don't know how big the radiator is, how
much coolant it holds, or how fast the coolant is pumped.
But I do know that Evans stands behind their product. I have seen
that they will buy the coolant back from you if it doesn't meet your
So to try it, all you're out is a radiator cap.
I'd say, install it on a mild weather day, and try it out. Watch your
gauge. It may run a bit warmer than with water/EG mix, but that's OK.
Ride on successively warmer days, and keep an eye on it. If the gauge
tries to top out, then Evans isn't for your machine. But if, as I
suspect, it stays in a normal range, then you're OK.
And then I bet you'll see one of four things, if not all of them--
You'll get better fuel economy. The engine will run smoother. You'll
have more power. You can reduce they octane of the fuel you burn. These
are the POSSIBLE benefits of running a coolant that doesn't boil in the
hotspots of the heads.
Now, Water Wetter may give you the same benefits. But one benefit it
certainly will NOT give you-- It can still boil over and leave you
stranded in the middle of nowhere. Evans NPG won't.

This is now my third season running Evans NPG. I see no need to even
consider changing.

Dave Haggard


1,556 Posts
Discussion Starter · #19 ·
I have noticed my fuel economy has gone UP about 2 MPG with the Evans coolant. Reading up on octane, I am going to see how mid-grade gas runs in my Rune. At a 10 cent/gallon savings, I will save $100,000 over the next million miles on my Rune if it will not knock or ping on midgrade!

The fans definitely come on "sooner" and stay on "longer." As the summer heats up I will keep you all posted.
(32,250 miles)
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