What will make the Viff run cooler?

My 2000 VFR doesn't seem to cool itself well anymore. As in, running at 70mph+ for twenty minutes in 75 degree weather, the temp hovered around 225-235. I can hear the fan running when I slow down.

I have 55k miles on the original thermostat and water pump; I changed (most of) the coolant about a year ago, when I checked the valve clearances. My question is what, in your informed opinion, will most likely help keep the engine temps down when I travel this summer:

- Replace the thermostat (does this ever start opening insufficiently as the wax ages?)
- Replace the water pump (I bought a new one two summers ago when I noticed a slight coolant weep, but I haven't installed it yet for laziness and procrastination; the coolant drip vanished)
- Make the fan blow air outside instead of in (I've read of people switching the fan blade with one from a... Fireblade? not sure)
- Any combination thereof...

or anything else that's worked for you.

Thanks & Keep the Shiny Side Up!

 

THAT sounds like the perfect candidate for a new thermostat. Something's definitely not right there and that would be the first thing I'd try...assuming the coolant level is good.

 

Different water pump won't help.

Your cooling system could be underfilled or have air pockets.

 

Try the t-stat first. It is cheap and easy... and a common problem though they usually get stuck open causing the bike to run cool. I can't say I've ever heard of a bad water pump on the VFR but that doesn't mean it can't happen. Regarding your question as to whether it stops opening efficiently, yes it does. When this happens the thermostat gets stuck either open or closed. Sounds like yours is closed and thus not allowing the bike to circulate the coolant. Perhaps it is cracked open just a tiny bit and letting just a tiny bit flow.

Check to make sure that the radiator cooling fins aren't bent or damaged all to hell. Bent fins mean inefficient cooling. Lots of them means a lot less cooling is happening.

In changing either the pump or the t-stat, you'll be getting new coolant in there to make sure that isn't the problem.

Isn't the cooling system essentially the same for 5th and 6th gens? If so then the left radiator shouldn't really get warm till the thermostat opens. As the bike warms up, you should definitely notice an increase in the temp of the right radiator as it will probably get so hot you can't touch it. The left one will get warm but you should be able to touch it till the bike hits about 180 degrees or so and then coolant will start flowing to it. If you are at 200 degrees and can still touch that left radiator... your t-stat is stuck closed.

I'd be shutting her down with the exception of test rides till you have solved the problem. Warped engine parts due to heat are very costly.

 

fan fuze blown?

 

Add some RED LINE WATER WETTER to your coolant mix, worked wonders for my bike!

 

+ 1 @ Squirrelman. Sounds like time to do some maintenance! Get a new t-stat, put that and that pump you've been putting off at the top of your list, and get some good fresh coolant in there.

 

You need to replace the T-stat. It is common for them to get stuck. Mine was stuck open luckly so I never had an overheating problem but the engine ran too cold and got terrible mpg. I replaced my T-stat with a honda civic but next winter I'm going back with a stock one. The opening is bigger than the stock one and I think that is what's causing my bike to run colder than it should at moderate outside temps. The t-stat is working cause it doesnt take forever to warm up like it did when the t-stat was stuck open.

You could also be running real lean. With higher rpms, your ignition advances. Have more air then fuel entering the chamber then you have yourself problem.


He changed coolant over a year ago. I highly doubt there's air in his system still.


No cooling system should need an "additive" to cool properly. Change the t-stat, coolant, and check for ECU codes and lets go from there.

 

Nope. Not unless he is mistaking the sound of something else for the fan.

 

correct me if im wrong, but if the t-stat is stuck closed, then you should be able to check and see coolant not circulating from the radiator fill cap. I forget what the t-stats are set to open at but find out, (180f) or so and let the bike get to that temp and see if it starts to circulate or not. I had to replace my t-stat on my 06 vfr with 10k miles on it but it was stuck open.

I thought it was a bit of a pain in the ass to get to. Had to remove fuel tank, air breather, and throttle body's. Wasn't much fun.

 

I didn't want to do all the work of getting to the thermostat unless it was absolutely necessary... but I realized I might as well bite the bullet now.

It wasn't exactly easy Took me three hours to get to the housing last night, probably forty-five minutes to get the throttle bodies off.

Action's writeup on changing his t-stat was helpful, especially the special tool he uses to loosen the throttle body boots: blow dryer.
http://vfrworld.com/forums/mechanics-garage/11331-thermostst-replacement.html

Some of the hoses are connected differently on my fifth gen, but mostly it's the same bowl of spaghetti.

My air filter was filthy, so I ordered another one... forty bux at some powersports-network site, fifty at bike bandit.

I haven't gotten things back together yet, I have to replace a small cracked hose; I'm thinking reassembly is gonna be tedious.

There was also a little bit of oil coming into the airbox from the hoses coming in from the valve heads. Is a sign of something else that needs maintenance, other than a rather clogged air filter?

 

The fan is fine, except the sucking-in-instead-of-blowing-out design. I ordered a VTR1000F fan blade to see if that will help in slower traffic, but I figure if the bike ain't cooling at higway speeds, something was wrong with coolant flow or the radiators.

I'm not sure what VFRworld's policy is on posting outside links, but there's a thread on VFRDiscussion.com that shows how the VTR fan blade blows air out instead of sucking it in as VFRs do.

Testing, 1, 2, 3: Tired Of Having A Hot Vfr? - VFR Discussion

 

Thanks gang!

I'll let you know how this pans out when the weather gets warmer. I've been able to sneak one ride in so far this February, but at thirty degrees, there ain't a chance in hell it's gonna overheat no matter what my thermostat is doing.

 

The little bit of oil in the airbox is normal I guess. My 06 has it and so did my 04, but it is a very small amount. So was it stuck closed? And did you replace the seal on the t-stat housing?

 

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"He changed coolant over a year ago. I highly doubt there's air in his system still."

Can't agree, Tex, cuz the level of coolant should to be checked again 2 rides after coolant refill. It usually goes down.

 

I guess by easy I should have said it isn't highly technical. A few bolts, a few screws, lots of cussin, a few beers, and it is done and over with.

Have you tested the old one to see if it is stuck closed? Just throw it in a pot of water on the stove and turn the heat on with a thermometer in there. It should begin to open at 176-183F and be fully open (8mm) by 203F. I'm curious myself as to if it was stuck or not.

As Adam said, a little bit of oil is normal. I'd define a little bit as a light film of it. This would be coming back from your PAIR valves. Should there be more than a little bit, I would suggest checking the reeds inside there to make sure that they are functional and they are sealing well... or ordering some PAIR valve block-off plates and just remove the system.

 

Lots of cussing.

 

I understand that. I'm going with the feeling that he has common sense.

 

I have done the VTR1000 fan mod,( It gets very hot here in Adelaide), but I also fitted a manual override switch so that I can turn the fan on whenever I want, usually when I know that I will be stationary or moving very slowly and the temperature has already gone 90degC +.

there are pros and cons for this mod, firstly the pros. the fan works way better as long as you are moving, even if slowly, because the fan is not fighting the natural airflow, and being able to turn the fan on early is a huge bonus, because I figure its better to stop the motor getting really hot in the first place. Of course an option would be to fit a lower temp thermo switch for the fan rather than a manual switch.

The cons of this mod are that the air inside the fan is pre heated by the exhaust headers and engine, and if you are stationary for a long period of time on a hot day, the cooling isnt as effective as it would be if you were sucking the cooler air from the outside of the bike as per the standard fan.
I would not go back to the standard fan for my type of riding
I have found that by eliminating the low speed lean running by fitting a powercommander and suitable map is very effective at making the engine run cooler, as is eliminating the catalytic converter. These bikes are very lean in stock form, to pass emmission regulations I guess, and the cat gets cooking hot.

I was also wondering if a lot of our thermostsat stuck open failures are caused by the engine getting so hot in certain situations that it causes the wax pellett to overload and not be able to close down again properly when it needs to in cooler weather??.

 

replace the thermostat, thats all you need