Greetings, fellow enthusiasts. Just picked up a pretty acceptable '04 VFR800 to mostly commute on. If it works out, I'll likely be taking some longer weekend rides. Couple of questions as I get familiar with the bike and the forum; Is it normal to see coolant temps approach 240 degrees F sitting in ~75 degree traffic? Also, are there any off-the-shelf exhaust systems still available for our 6th gen bike, or am I looking at custom fabbed stuff? Also, is there a compiled list anywhere on this site for required/recommended upgrades/modifications for our bikes? Here she is in her 35k mi. of glory: I look forward to getting to know y'all. -Smote
Welcome! 240F seems high to me. Do the fans come on, cool the engine, then go back off? Have you checked the coolant?
Memories of my first VFR, a 2004 Italian Red, still registered and out there somewhere. Agree with bmart 240degF is way too high. Service Manual states cooling fan should come on between 208 - 216degF. You can at least view the Reserve Tank coolant quantity by looking at the rear of the left side fairing (forward of the clutch slave cylinder area). In general these bike get hot no matter what the ambient temperature in stop/start traffic or stationary, the cooling fan should be cycling in this situation.
Seems high to me, as well. The fans do come on, then turn off somewhere around 220F. I am planning a coolant/radiator flush in the very near future. Also in the plans is a manual fan switch.
I will nudge you to check the overflow also...but the actual coolant system for air at the top or in there somewhere. If you have air in there, it is going to go sky high without any relief until you turn it off.
I was wondering about that. On my ride home on this ~70F day, the temp fluctuated between 205F-230F seemingly regardless of speeds. Is there a preferred method for bleeding the cooling on our bikes?
Generally, if they're on a flat surface adn on the side stand, the filler (on my 5th gen) is the high point. Burping consists of blipping the throttle a few times and continuing to fill it to the rim...check once cool. Reinstall cap and check overflow. Air in there will absolutely run hot and nothing will solve it but removing the air. You don't want it running at 250F all of the time.
Might be that your overflow is dry and it can't suck coolant in (to replace air) when it cools down.... check rad on the side stand and top it off, your first clue if it's low..... fill the reservoir to the max line and go through at least one if not two hot and cold cycles. If coolant level in the reservoir drops a bit, then you'll have a good indication some air was replaced. If it continues to run too hot after that, at speeds above say 30 mph, might indicate the thermostat needs replacing. But, ensure rads are clear of debris, etc. as well.
From my spreadsheets (I love VDC adn coolant temps at every fill up of fuel), my '98 runs around 177F with a highest seen of 220F stopped in heat. My '00 is nearly identical with the highest of 223F. They are both properly burped after a system cleaning over the winter.
Thanks, all, for the tips. Turns out, you were right. A cooling system works better with coolant in it. Who knew? After pulling the plastics to check radiators for debris and finding the overflow pretty dry, I ended up adding almost a gallon in the radiator(s?). Today's ride home saw a max temp of 201F. I feel much better. Now, to the exhaust. Is there anything still readily available, or am I going to have to employ my fabrication skills?
