Flush that coolant on these old bikes
Thread Starter
Senior Member
SuperSport
Joined: Aug 2007
Posts: 714
From: Fredericksburg, VA
Flush that coolant on these old bikes
Well I just finished flushing my radiator on my 98 with 32,000 miles. Many of us here have '98s and let me tell you how dirty and brown it was.
Simple checking of the coolant level was something I have never really done before on a motorcycle, I just get on and ride. But to help preserve these old machines would be beneficial to dust off that shop manual and do an easy flush.
Earlier this year I switched to water but never "flushed" the system so I've finally taken the time to get this done while waiting for a new radiator cap, which BTW was not working properly due to the rubber seal being expanded from age allowing coolant to flow freely into the expansion tank. The whole process is REALLY easy and I used Prestone Radiator Flush from Autozone to do it. This is something I will probably start doing annually now, just to make sure everything stays fresh. I refilled it with distilled water and Water Wetter, but I'm not sure what to do about the frigid temps. Maybe start it every couple days and let it warm up? Either way is has fresh juice so she'll be ready for some more flogging!
Simple checking of the coolant level was something I have never really done before on a motorcycle, I just get on and ride. But to help preserve these old machines would be beneficial to dust off that shop manual and do an easy flush.
Earlier this year I switched to water but never "flushed" the system so I've finally taken the time to get this done while waiting for a new radiator cap, which BTW was not working properly due to the rubber seal being expanded from age allowing coolant to flow freely into the expansion tank. The whole process is REALLY easy and I used Prestone Radiator Flush from Autozone to do it. This is something I will probably start doing annually now, just to make sure everything stays fresh. I refilled it with distilled water and Water Wetter, but I'm not sure what to do about the frigid temps. Maybe start it every couple days and let it warm up? Either way is has fresh juice so she'll be ready for some more flogging!
Member
Squid
Joined: Oct 2008
Posts: 39
Water Wetter
I have yet to have water wetter freeze up on me. And I ride all year long. I do keep my bike in a garage but none the less I have never had it freeze. Well now I think about it my garage doesn't get below 35 degrees either. But it does get pretty dang close.
Senior Member
Back Marker
Joined: Mar 2006
Posts: 198
From: Atlanta GA
be very careful with just water and WW. I've seen many a bike break in a feb race because the radiator froze. outside cold starting under 35 can be murder. if your not at the race track why not use bike specific antifreeze with WW
Senior Member
SuperBike
Joined: Sep 2005
Posts: 1,572
From: Buffalo, NY
They say antifreeze loses its corrosion protection after a few years so I like to change it every 2 to 3 years. Its cheap enough and not that hard to do. I use antifreeze, distilled water and water wetter as it can get to 0 degrees or a little below here in NY. Just my .02
Thread Starter
Senior Member
SuperSport
Joined: Aug 2007
Posts: 714
From: Fredericksburg, VA
How do you keep your garage warm? I was thinking about parking them in the basement when it gets REALLY cold.
Senior Member
SuperSport
SuperSport
Joined: May 2005
Posts: 809
From: North Wales, PA
in 55 degree weather, my needle never makes it past the 1/4 mark. in 80's weather, it hangs right around the half mark or between that and the 3/4 mark. but never actually touches the 3/4 mark. the hot side of half way is about as hot as it ever gets.
Senior Member
Superstock
Joined: Mar 2008
Posts: 287
From: Brooklyn, CT
I was out Sunday when it was in the upper 60's and it hung right around 1/4. 80's to 100 it runs no more than a tad over the half way. Even idling in traffic the fan keeps it that temp.
I don't think WW has any anti-freezing properties. Definately do NOT let it sit below freezing for any length of time. A 25 degree night will most likely crack your block. I would switch to antifreeze or drain it/blow it out.
Nose Picker
Back Marker
Joined: Oct 2008
Posts: 130
From: Tacoma, WA 98408
I just flushed my coolent and i have noticed a drop in tempature. Thanks for the reminder. Oh also you may want to flush your dot 4 fluids. My clutch fluid was near empty and it was real dirty and thick. And both breaks res were dirty and thick as well
Senior Member
Superstock
Joined: Jan 2008
Posts: 499
From: Kansas City
Member
Squid
Joined: Oct 2008
Posts: 64
coolant temp
My temp needle was under the 1/4 mark on a 55 degree day. I haven't ridden it yet at 80 plus degrees. I just wanted to be sure it was hot enough to burn the water/condensation out of the oil. I
Really I thought the thermostat might be stuck open - i was going to investigate. If my temp sounds normal - great.
Thank you.
Darren
Really I thought the thermostat might be stuck open - i was going to investigate. If my temp sounds normal - great.
Thank you.
Darren
Member
Squid
Joined: Feb 2008
Posts: 94
From: Jupiter, Florida
According to the shop manual, you need to remove a drain plug on the front cylinder head. I can see it but not really sure how to get to it. (Full fairing removed). Is that necessary to get a good flush of the radiator? Manuel also says to flush with clean water. Is it necessary to use a commercial flush? Bike is a 99 with 16K on it. I'm doing this because I had to take a hose off to get at another part and think I got an air bubble in the system as it began to overheat on the next outing. The cap looks fine but again, its a 99. Should I replace it while I'm in there? I don't really have any way to test it.
Senior Member
MotoGP
Joined: Jul 2007
Posts: 5,066
From: NYC
I would recommend pulling the water pump hose too. (or instead of that tiny plug)
No way would I run water wetter anywhere near when it would freeze. Even my racebikes spend the winter with antifreeze to keep everything clean.
No way would I run water wetter anywhere near when it would freeze. Even my racebikes spend the winter with antifreeze to keep everything clean.
Retired- but not tired!
SuperBike
Joined: Aug 2010
Posts: 1,481
From: Pittsburgh
I would replace it on principle due to its age. About $6 or $7 at any auto parts store. If you look through the forums many folks have cured an apparent "overheating issue" just by replacing the radiator cap with new. GL, YMMV.
Senior Member
MotoGP
Joined: Jul 2007
Posts: 5,066
From: NYC
I agree, replace it. Rarely can you save so much hassle so easily or cheaply than doing this. Its a common cap, lots of cars use it too, avail at auto parts stores. I put a list of crossover models on a thread here somewhere.
Senior Member
Back Marker
Joined: Nov 2007
Posts: 125
From: Dayton,Ohio
radiator cap cross reference
An alternate to oem is Stant #10233 available at Advance Auto for 7.49. 1.1 bar=16lb. I found my gasket was split on the original cap while I was changing coolant. I also found my overflow bottle was plugged. I unhooked the overflow hose to drain the bottle and nothing came out. I used my compressor to clear the blockage while flushing the bottle with a hose and let the sediment float out.Just wanted to share this because the overflow function probably rarely gets tested
Senior Member
MotoGP
Joined: Jul 2007
Posts: 5,066
From: NYC
You can get it pretty clean with a warm water and white vinegar solution too. Just make sure to NEVER use tap water as half you coolant. Only use distilled . Tap with cause scaling and rust due to its minerals.
Fill the system with water and vinegar and run the bike up to warm then let it sit, then drain it.
Fill the system with water and vinegar and run the bike up to warm then let it sit, then drain it.
Senior Member
Back Marker
Joined: May 2018
Posts: 106
From: EU
How much running does it take to take all the air out of the cooling system?
As per the instructions from the manual- I let the bike idle for about 5 minutes, with the cap off, revving it for a bit at times and constantly topping the coolant up until it didn't drop any longer. I then let the bike sit for about 1h, removed the cap and the level had dropped by 30-40ml.
I don't want to have to remove the fairings again to air bleed or top up the coolant...
As per the instructions from the manual- I let the bike idle for about 5 minutes, with the cap off, revving it for a bit at times and constantly topping the coolant up until it didn't drop any longer. I then let the bike sit for about 1h, removed the cap and the level had dropped by 30-40ml.
I don't want to have to remove the fairings again to air bleed or top up the coolant...
Administrator
MotoGP
Joined: Apr 2006
Posts: 4,402
From: Kempner, TX
How much running does it take to take all the air out of the cooling system?
As per the instructions from the manual- I let the bike idle for about 5 minutes, with the cap off, revving it for a bit at times and constantly topping the coolant up until it didn't drop any longer. I then let the bike sit for about 1h, removed the cap and the level had dropped by 30-40ml.
I don't want to have to remove the fairings again to air bleed or top up the coolant...
As per the instructions from the manual- I let the bike idle for about 5 minutes, with the cap off, revving it for a bit at times and constantly topping the coolant up until it didn't drop any longer. I then let the bike sit for about 1h, removed the cap and the level had dropped by 30-40ml.
I don't want to have to remove the fairings again to air bleed or top up the coolant...
If there was a lot of air, it might take a second full cycle.
Of you can fill the system with a vacuum filler and have zero air in the system from the get go.
Senior Member
Back Marker
Joined: May 2018
Posts: 106
From: EU
Thanks! It got me intrigued a bit because this is the first time when the manual calls for open cap bleeding, everything else so far (even for cars) just said "fill to the top, run for a while, then check the level"
So the bike should be ready to ride now...
So the bike should be ready to ride now...
Senior Member
Back Marker
Joined: May 2018
Posts: 106
From: EU
If I let the bike idle for too long the neighbors will likely call the police...
One more thing- I've reread the manual and they say that the coolant capacity is 2.9l for the rad + engine, and 0.71l for the expansion tank. So this means 3.61l total capacity... Last time I read the manual I only saw the 2.9l part, and bought 3 liters of (premixed) motul motocool expert coolant. This means that there are (or were- maybe some of it got up by now) 0.6-0.7l of air, and the same amount of missing coolant...
ps: (this gets more and more complicated)- I wanted to not cheapen out and buy the best quality coolant I could find. This seemed to be the Motocool expert, which probaly was also the most expensive coolant I've ever bought. However the manual says that silicate may cause wear of the waterpump or radiator blockage. What the hell should I do? Get new coolant?
Administrator
MotoGP
Joined: Apr 2006
Posts: 4,402
From: Kempner, TX
silicate is abrasive, becomes a solid and why is not recommended for aluminum motors or cooling systems. Will it have long term effects in a year? likely not. Id likely run it for the season then change in year.
The cap needs to be on when its running, you can burp some air before running it with the cap off, top off and then run it... but otherwise, just put the cap on and ride it. .
The cap needs to be on when its running, you can burp some air before running it with the cap off, top off and then run it... but otherwise, just put the cap on and ride it. .
With the cap on?
If I let the bike idle for too long the neighbors will likely call the police...
One more thing- I've reread the manual and they say that the coolant capacity is 2.9l for the rad + engine, and 0.71l for the expansion tank. So this means 3.61l total capacity... Last time I read the manual I only saw the 2.9l part, and bought 3 liters of (premixed) motul motocool expert coolant. This means that there are (or were- maybe some of it got up by now) 0.6-0.7l of air, and the same amount of missing coolant...
ps: (this gets more and more complicated)- I wanted to not cheapen out and buy the best quality coolant I could find. This seemed to be the Motocool expert, which probaly was also the most expensive coolant I've ever bought. However the manual says that silicate may cause wear of the waterpump or radiator blockage. What the hell should I do? Get new coolant?
If I let the bike idle for too long the neighbors will likely call the police...
One more thing- I've reread the manual and they say that the coolant capacity is 2.9l for the rad + engine, and 0.71l for the expansion tank. So this means 3.61l total capacity... Last time I read the manual I only saw the 2.9l part, and bought 3 liters of (premixed) motul motocool expert coolant. This means that there are (or were- maybe some of it got up by now) 0.6-0.7l of air, and the same amount of missing coolant...
ps: (this gets more and more complicated)- I wanted to not cheapen out and buy the best quality coolant I could find. This seemed to be the Motocool expert, which probaly was also the most expensive coolant I've ever bought. However the manual says that silicate may cause wear of the waterpump or radiator blockage. What the hell should I do? Get new coolant?
