I had own a 10year old 02 vfr800 vtec
Lately it has been having overheating issues which I failed to resolve.
This is what happens:
Bike is operating fine as along as it is on the move.
However when stopping at traffic junction or stuck in a jam, radiator temperature will keep rising and even when the fan turns on @ 105 degree C, it will fail to reduce the temperature. (temperature will only rise slower)
One of the fix that I did was to flush the coolant. (leaving the bike overnight on side stand and fill it up with coolant while on side stand)
I also make sure that all air bubbles are cleared by blipping the throttle.
The flush will temporary remediate the overheating issue for a few days and the same symptoms will reoccur again.
I have done 3 rounds of topup of coolant+clearing of air bubbles (overheating will always occur after a few days) and had noticed these:
- There seems to have a drop of coolant in the system everytime I did a topup
- Coolant reserve level is always consistent; no drop in water level which I find it strange.
If there is a leak somwhere shouldnt the system top up it's coolant from the reserve?
- Unable to find any water leaks so far; unless its a slow leak which has evaporate way before it can be seen.
More info: I had replaced the radiator cap a few days ago and the thermoset & radiator fan switch has been replace 6 months ago. Using a mixture of distill water+water wetter.
I hate to mention the "o" word, but what does your oil look like? It sounds to me like it could be a blown head gasket. Air is being introduced into your system somehow, and I believe this is why your reserve tank is staying at it's same level.
Hopefully I'm wrong, but it's worth a look.
How hot is it where you're at right now? If it's a really warm day and high humidity, I've experienced what you're talking about (fan comes on but still doesn't really want to cool down).
But if it's moderate temp out (70-80) and the bike is just sitting and idling, it should go through the normal cycle. Fan on at 220°F, cools to 200°F, fan off, bike warms up, repeat.
As to your 'disappearing coolant' issue, so long as your oil isn't chocolate milk *crosses fingers*, there are really only two options: it's either leaking out or you have more air trapped in there than you thought. Are you doing this with the bike on the center stand or the side stand? I just went through this the other day when I converted to Engine Ice. The first time I filled it up was on the center stand. I warmed it up, blipped the throttle a couple of times, and called it good. I came back later when it had cooled off, and to my surprise the level was lower than what I had left it at. So, for Round Two, I put it on the side stand, and this time I let it get warm enough that the coolant was steaming a bit and overflowing ever so slightly out of the top. I gave it some good hearty blips until I wasn't getting bubbles/cavitation coming up through the coolant, then shut it down. I topped it off once it was cold, then put the cap back on. Checked it the next day and it was good to go.
Mike
The vfr needs antifreeze as it runs hotter than boiling point as a Norm. If you fluid is all boiling I wouldnt expect the fan to do much.
spud786, on 10 May 2012 - 04:03 PM, said:
The vfr needs antifreeze as it runs hotter than boiling point as a Norm. If you fluid is all boiling I wouldnt expect the fan to do much.
My understanding is that the rad cap pressurizes a cooling system, thus raising the boiling point. So even if running plain ol' tap water it shouldn't boil until some temp higher than the atmospheric boiling point for water (~212°F). I THINK the cap for our system is 16lbs, which I THINK means it raises the pressure 16psi relative to 1 atmosphere (so about 31 absolute). So, following that logic, the new boiling point should be about 250°F based on this chart:
http://www.engineeri...ater-d_926.html
That, to me, would explain why the warning light on our bike trips at 250°F. But again, this is all just my theory.
My point, though, is that I don't think a system running water (with or without Water Wetter) is boiling out in normal riding conditions, provided the system is holding pressure.
*EDIT*
Did a little research on this real quick. I hate to cite Wiki, but it works for this. Here's the page for ethylene glycol, the chemical typically used for antifreeze:
http://en.wikipedia....Ethylene_glycol
Very interesting info on boiling point, especially the chart about halfway down. And, for reference, that chart appears to assume a system at 1atm. So yeah, EG DEFINITELY raises the boiling point. Of course, it depends on how much EG is in the antifreeze mixture itself, but assuming antifreeze to be 100% ethylene glycol, a 50/50 mix has a boiling point 13° hotter than pure water. Impressive!
Mike
Its always the distilled and watter wetter guys, who seem to have boil over issues. Water wetter says right on the bottle as a warning does not raise boiling temp of water. Under pressure does raise it slightly, but the vfr runs on the warm side , and seems to have more trouble complaints with distilled and water wetter than other bikes, with the threads that get posted on this topic.
Now , Im just going off years of VFR Boil over threads, But I run about 70/30 mix of antifreeze, my hydrometer says good to about 270 degrrees, as the antifreeze level decreases, the hydrometer says boil over protection degree decreaces. Ive also never boiled over or had issue sitting stalled in 110 degree traffic in bright sun shine, on the vfr (ever). Im pretty sure plain water would get a very poor reading on that Hydrometer.
But seems there's always something common in most the vfr boil over threads that ive seen, and its distilled and watter wetter combo on the vfr.
But what I am suggesting, Before trying to turn fans around backwards ect which usually acompany those boil over threads, on a system design that works fine , atleast run chemicals that are made to prevent boil over.
@mk2davis: I haven't really check the oil condition; I hope there will be a quick way to check the oil without draining it out :(
@whiteboyslo: Unfortunately, the when the fan turns on at 220°F, it doesn't go down to 200°F, sometimes it stays at 220°F or even go higher until the bike gets moving again.
Yes, I am doing the blipping on side stand, usually put the bike on side stand overnight and do the topup, blipping.
@spud786: I have been running water wetter/distilled for more than 8 years on this VFR, somehow this is the first time I had the coolant issue.