tap water in sheffield is as soft as a baby's arse..I use that, boiled.

Silicate free antifreeze has been about for years, especially in Jap cars and bikes, mainly becuase of aluminium engine blocks. It used to be the weird green stuff you saw in an old Nissan or Toyota.

The silicates (sand) don't cool the engine, they act as a cleaner / corrision inhibitor by scrubbing away at the engine as they go around the system. Over time these have a plating action on the aluminium and also tend to sludge up and form sand, which eats away at the fine, high revving water-pump in the motorcycle.

Using a silicate free anti-freeze will ensure you don't have any problems, even if you forget to change it regularly.

To change the coolant on the VFR.

Undo the drain bolt in the water pump, there are two bolts under the front exhaust headers that will also help drain and remove the rad cap.

I take this opportunity to remove the lower rad hose and flush loads of clean water through the rad and block, both ways to ensure that any residual junk is washed out. when it is running clean I reconnect it all up and attach the drain bolts once more.

Now. Put the bike on the side stand and mix up a load of anti-freeze and distilled water.

I use 50/50 in the winter and if im runnin through the summer 30 antifreeze / 70 water (anti-freeze isnt as good as cooling as water, but it does inhibit corrosion and stop freezing)

Fill the bike up on the side stand to the top of the rad, make sure the expansion bottle is filled up to the max mark too.

squeeze any hoses to get air to come up and fill up the rad again.

Run the bike with the rad cap off until the engine is warm (temp at half way) and then snap the throttle to raise the revs to 5000rpm and let it settle. Repeat this step 3 -4 times until no air bubbles come out, you will notice the water level rise / fall and maybe over-flow a bit with the cap off but this is normal.

Turn off the engine and allow the bike to fully cool down... then top up the water to the top and put the cap on.

(taken from honda manual and procedure i use, never had problem)

they recommend 50 distilled water and 50 silica free antifreeze btw

I am working in a chemistry company:-) Once again, dont mix pure destilled water with any coolant:
Background:
Coolant have 3 funktions: antifreeze, anticorrosion, set up the boil hot spot.
2 types: silcat and silicat free
antifreeze is the same. ethylenglycol- no problem
anticorrossion: the old silicat coolants are the best for anticorossion, but they loose this function with time. So its recommend to change coolant (typical 4 years). All silicatcoolants was in use in the 70 when comes the first engines with aluminium zyl heads! so finaly you can use this coolants for all materials too, if you change it from time to time.
If you dont do this, you loose this great anticorrosion function of the silicat type. And this was the great problem, especially on aluminium Motors. People dont change coolant and the parts rusts or take a chemical reaction well. The VW VAg Company and BASF developed a coolant in the 90 which was silikatfree and a other chemical way (red, G12,G30). This coolant was providen as a coolant especially for alúminium motors. but thats not the real story. It was a coolant for lifetime fillment! , but with less performance of anticorossion on this lifetime. they know this after experiance with it and devolepmed the lila G12+ coolant, with gives a further performance of anticorrosion, but anyway not so good like a new "old" silikat coolant. The latest one is the G40 BASf spec or G12++ which have a specially silizium additiv package in it, and that works rear close to the silicat types in the anticorrosion section.
All silicatfree coolant gives a improvment into boil hot spot compared to the old style silicat coolants.
So for this case they developed a silicat coolant with top performance in boil hot spot- an this one is called G48 (green).

my opionion:
-if you want a lifetimefillment with good anticorrosion- G40/silicatfree
- if you want the best performance overall and you change coolant for some time- G48-silicat
All racecoolants are silicattypes! Look into the castol or Motorex Coolant- its blue-green (silikat!!!)
BMW and Daimler recommendation is silikat too:-) its greenblue too:-)

Never heared that silicatcoolants have sand in it.
silicates for coolants are inhibitors of ester and salts from Si(OH)4
sand= Quartz= Mineral= SiO2

Water: i use ordinaly groundwater, if calc is in it - drinkminaralwater without gas
dont use destilled!
or main-supply water-because it is chlor in it- aggressive

So, can car coolant be used in bikes, then?

If so/not, then which?

Just checked mine - tank is stained, so looks an ok level, but inside, can't see any liquid!

Chemistry lessons aside are you basing any of this on real-word usage?

Antifreeze will raise the boiling point of the coolant yes, so will pressurising the water.

There was a spate of water pump failures on several Honda models, especially the gold-wing bikes. Honda investigations as well as independant tests (I think MCN did this test) determined that the silicated in the anti-freeze had damaged the waterpump seal.

Sand is a common reference to the silicates included in anti-freeze. The most common element in sand is Silica (SiO2 / Quartz) not sure which specific silica is in most brands of antifreeze as they often just state silica.

These tiny particles act as a scrubber for the engine, cleaning away and deposits.

Honda recommended (and still do) their own brand of anti-freeze (which is silica free!) and to mix it 50/50 with distilled water.

Tap water is really not a good idea! Especially in the UK there are a lot of hard-water areas (many mineral deposits in the water), anybody who uses a shower or kettle in these areas will have experienced lime-scale effect on shower-heads, kettles etc.

Lots of the minerals, especially in ionic form introduce bimetallic corrosion in the engine. If you change the coolant regularly (I do mine every 18 months) you shouldn't technically have a problem even with tapwater as the antifreeze has anti-corrosion built in and this will not have worn out by the time the coolant is changed. If you dont change it for a long time though the anti-corrosion in the antifreeze will wear out and your minerals in the tap-water will be free to corrode the engine.

Honda recommend change coolant every 2 years.. the 4 year you quote is what most common automotive manufactureres used to reccomend when they used silica based anti-freeze.

Distilled water is better as it has most of the minerals / ionic compounds removed from it, which I summise is why Honda recommend using it.

I haven't studided chemistry for 10 years and it wasnt to a high level so some of my terminology might be wrong

You seem to be basing your statement on automotive use, BMW / Daimler, of which many do use silica based coolants, car waterpumps are a lot sturdier than a motorcycle pump and also dont rev as high. Think Silica particles hitting an impeller at 16,000rpm vs 6000rpm.

Race Coolants:

Are you talking MOTORCYCLE race coolants or CAR race coolants?

PUTOLINE ICE MOTORCYCLE RACE ENGINE COOLANT ANTIFREEZE (GREEN) - My choice.

Putoline Ice Cooler is a silicate free long-life coolant based on Nano Technology and Mono Propylene Glycol (MPG).

MOTREX

Motorex Anti Freeze - 1 Litre

The largest independent crude oil refinery in Switzerland - 86 years of experience

Ready for use Anti Freeze for water cooled Motocycle and ATV engines
Ethylene glycol base concentrate is blended 50/50 with de-ionised water to make this product ready for use
Especially suited for aluminium and magnesium engines - While not specifically stated this product is silicate free (G48) motorex
Free of nitrites, phosphates and amines
Protection down to -40°C



I cant find the actual Honda manual at the moment, but this is from a KTM manual that I could find.. they reccomend using distilled water too, along with the sillicate free anti-freeze

I don't know how you can be arsed Neo.

On a side note I'm running 70% distilled and 30% ethyglycol thingymajig(castrol) here in SA usual temps to 32C and lowest(but rare) 16C(year round)