Looking for coolant recommendations for Yamaha street bike

**joed66** · 04-06-2012, 10:18 PM

Originally Posted by subaron

Thanks for all the replies guys!

I am considering Honda Type 2 Antifreeze/Coolant considering the price is similar to others at CT.
Now I am not sure what coolant the previous owner ran or if was even changed or topped up since the first owner got the bike (its a 2005). I from what I understand its not good to mix coolants.

Any suggested ways on doing a coolant flush? I was planning on the following steps:
1) Emptying out the current coolant
2) Run distilled water for a quick ride...let the bike cool down and empty distilled water
3) Fill Honda Type 2 and be done with for a couple years.

...but as forums and internet go I read about using some flush but did not say how since the bottle is half a liter and I would need to buy a few....unless it is mixed with distilled water. Then I read that its too had for motorcycle radiators and cooling system and its better to use distilled water mixed with vinegar (which almost sounds like bad advice).

You've got the basic idea, but you don't have to run distilled water in your bike then drain it.

1- Drain existing coolant into a bucket
2- With the drain plug still open pour distilled water in through the rad cap opening until the fluid runs clear at the drain plug
3- After you see the fluid run clear at the drain plug stop pouring the distilled water and let the remaining fluid drain completely
4- Close the drain plug and fill the bike with the specified amount (check manual) of coolant
5- Follow the procedure listed in your manual for bleeding the cooling system of any air or air bubbles (important)

Recommend you get the specific manual for your bike before you undertake this procedure. It will explain the correct method for changing your coolant.

**theassassin** · 04-16-2012, 02:23 PM

Originally Posted by Acadian1974

Not advisable to run non-motorcycle specific coolant unless you're certain it's silicate free.

BINGO +1!
Many OEM specified coolants have special "low silica" properties that are made to work specifically with the special type of pump seals that they have. They are sometimes noted as being "High Mileage" for a reason.
Some should make a note to be careful when advising others if you don't have all the information on a topic as it can cause others a lot of grief.

**subaron** · 04-20-2012, 06:21 PM

I did the coolant change a couple days ago. There was no mention of air bleeding in the manual.

I basically flushed the system with distilled water several times. Than added the coolant in the radiator and the reservoir tank to the max mark. I turned the bike on with the radiator cap off and let it idle for 10 mins. I saw some bubble come out. Then I put the radiator cap on and went for a ride. I checked the reservoir tank yesterday while the bike was on center stand and noticed that the coolant level is at the mid point between min and max mark.

Question: Should I top up the reservoir tank to max or leave it as is?

**imkruzen** · 04-21-2012, 12:11 AM

Are you running a 50/50 mix of anti-freeze and water? Here's why I ask: Anti-freeze is 10 TIMES heavier than water! If you are running a 50/50 mix, your engine is working 5 times harder just to move the coolant mixture around than if you were running straight water. Of course, water is extremely corrosive, so you cannot run straight water, right? Put only enough anti-freeze in your system that will get it to the lowest temperature you expect it to reach. Add redline 'Water Wetter'. This breaks up the surface tension of the water, making it easier for the engine to move the fluid around. And use distilled water, which does not have the heavy mineral content that tap water does.

**Brian P** · 04-21-2012, 03:53 PM

Originally Posted by imkruzen

Are you running a 50/50 mix of anti-freeze and water? Here's why I ask: Anti-freeze is 10 TIMES heavier than water!

The density of ethylene glycol is 1.113 g/cm3, only 11% more than water , which is 1.000 g/cm3 by definition. The VISCOSITY, on the other hand, is much higher. The viscosity of a glycol/water mixture is not a linear relationship, though, and for reasonable mixing ratios it makes little difference to the amount of effort it takes to turn the water pump.

Compared to water, ethylene glycol has higher viscosity, somewhat higher density, about half the heat capacity, but a higher boiling point and lower freezing point.

**imkruzen** · 04-21-2012, 11:50 PM

50/50 mix doesn't provide optimum cooling. To improve cooling in hot weather, use less antifreeze and more water, possibly going to a 25/75 or a 20/80 mix ratio. Temperature drops about 3 degrees C are typically obtained by reducing the mix ratio from 50/50 down to 25/75 or to 20/80. The boiling point of pure water is 100C. The 50/50 mixture increases it to 106C. Pure antifreeze has a boiling point of 113C Pressurized systems will raise the boiling point in those cases. At 65% anti freeze mixture you’ve lost 20% of the cooling capacity of the system. Antifreeze prevents corrosion, but even a 10/90 ratio of antifreeze to water will serve the purposes of inhibiting corrosion and adding such additives as water wetter helps. In some states where it never goes below freezing, anti-freeze isn't used at all, just the corrosion inhibitors. You want more water to increase the efficiency of your cooling system, but at least 10% coolant to keep O-rings and the water pump lubricated.