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99 not cooling correctly


Lint

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I has confuse.

My 99 VFR is running hot. I know, I know, it's what they do...
My fan works and comes on as scheduled, 225°. But, even with brand new distilled water and water wetter, after an extended radiator flush, it still heats up and even at idle, it won't come down with the fan. It just stays at that temp, whatever it may be. The fan can't bring it down and it's pulling hard. I felt it with my hand and it's definitely pulling air across the radiator.

My theory is either collapsed or misrouted hose, or thermostat partially stuck open. If I'm moving, the temp drops, unless there's traffic in front of me.

I'm stumped. I'm running zero antifreeze, just WW and water. I don't understand, with a normal coolant mix, it did this too. Coming up a canyon today it was at 233°. It didn't go past that, but my 6th gen only got this hot once. I even replaced my radiator cap today with a new one that is 1.4bar/20psi, because my bike was boiling at 250° with a standard 1.1bar/16psi cap a short while ago up on Mulholland.

I'm really kind of stumped.

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37 minutes ago, Lint said:


My theory is either collapsed or misrouted hose, or thermostat partially stuck open. If I'm moving, the temp drops, unless there's traffic in front of me.

 

 

I'm curious, have you (or a prior owner) ever replaced the thermostat?  Just a quick "yes" or "no" will do (and if not, why not?  It's a 19 year old motorcycle, give it some love).

 

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theres a long list of stuff to improve things.

 

remove radiators and degrease them thoroughly, the back side of the radiators gets seriously gummed up with road grime and blocks alot of the slits.

 

raplace your thermostat, before you replace it run a full system radiator flush without the thermostat installed

 

if doing all of that doesnt help, you can try the following mods.

 

install lower temp fan switch

wire in a manual fan switch

install larger 6th gen radiators, make sure they are clean as well

install the spal 5.5 in pusher fan, or install the reverse blade from an rc51 fan

 

if all else fails, you can convert to a front mount radiator from a suzuki tl-1000r

 

just an fyi make sure your body plastics are in good order in the front end to make sure air is directed over the radiators as designed.

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Thanks for the list.

 

I'm also considering removing the plastic piece that is in front of the headers. The previous owner installed Chinese fairings, so I'm thinking of removing that part and putting a brace across to bolt the side panels to. I've often wondered if they are blocking airflow.

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I'm having similar issues, and i bought a small long slim radiator from a unknown dirtbike that i want to mount in front over the oil rad instead of the tube that comunicates one radiator with the other.
I'll let you know how this thing goes because i don't know if it's gonna work

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Is this an actual problem? Sounds like business as usual for a 5th/6th gen.

The temp climbs and when it reaches a point the fan kicks in and prevents it from going any higher. The rider either shuts the bike off to let it cool or gets moving to allow air to move through the rads to cool the water temps.

I think ensuring the rads are clean and clear, and all the fins are straight (as fonque has already mentioned) is a good thing everyone should check regularly....but Lint it doesn't sound to me like anything is wrong with your bike.

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Ok, thanks. I just wish Honda had put the radiator in front! Where it belongs. 

I do know, from reading on the interwebs, that all the Honda bikes with side radiators, Goldwing included, that they all run hot. Maybe I'll try the VTR1000 fan. Get it to blow the other way.

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4 hours ago, slowbird said:

Is this an actual problem? Sounds like business as usual for a 5th/6th gen.

The temp climbs and when it reaches a point the fan kicks in and prevents it from going any higher. The rider either shuts the bike off to let it cool or gets moving to allow air to move through the rads to cool the water temps.

I think ensuring the rads are clean and clear, and all the fins are straight (as fonque has already mentioned) is a good thing everyone should check regularly....but Lint it doesn't sound to me like anything is wrong with your bike.

 

I agree.

 

I think we have to adjust ourselves mentally to the perceived higher temps. The bikes run fine at these temperature ranges. There is no need to modify them to run cooler. They last longer than most motorcycles made today! If heat was an issue it'd have killed a lot more along the way. We just see a big number and get anxious.

 

My only suggestion for Lint would be to drain the system and put the expensive Honda blue coolant 50/50 premix in. Will keep the water pump and passages happier for longer than WW+water.

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My 5th gen Would see temps in the high 230s regularly, that's not normal for any gas powered engine. 

 

However,  i had leaking hoses,  a semi functioning tstat, and radiators that looked like they had been sprayed with fresh asphalt. 

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31 minutes ago, thtanner said:

 

I agree.

 

I think we have to adjust ourselves mentally to the perceived higher temps. The bikes run fine at these temperature ranges. There is no need to modify them to run cooler. They last longer than most motorcycles made today! If heat was an issue it'd have killed a lot more along the way. We just see a big number and get anxious.

 

My only suggestion for Lint would be to drain the system and put the expensive Honda blue coolant 50/50 premix in. Will keep the water pump and passages happier for longer than WW+water.

Very good point about the longevity of the VFR.  And this obviously includes a lot of bikes that weren't maintained very well.

 

I agree with you, I've only owned my '99 for one summer and it's definitely true that living with the 5th Gen VFR during hot weather takes a bit of mental adjustment (compared to other vehicles I've owned).

 

For me the mental adjustment to achieve a comfortable feeling with the normal (but somewhat frightening) 5th Gen VFR temperature range was all about building up my confidence that the bike was healthy in spite of what the temperature gauge is reading.  This means knowing that the radiators are clean on the insides and outsides, that the coolant is in very good condition, that the thermostat is functioning properly, and that the engine oil is high quality (full synthetic) and in good condition.

 

 

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1 hour ago, Lint said:

Ok, thanks. I just wish Honda had put the radiator in front! Where it belongs. 

 

They did that with the 8th gen, and it runs in the same temperature range as previous generations. I can change the display to show MPG and outside temperature so I can ignore the reading and ride happily. :)

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