can i make it run cooler?

My 93 is the same way. On highway 65-85MPH I sit at around 1/4 or a little higher on temp gauge. Once I slow below 35mph in traffic etc the temp starts to creep up depending on conditions. If its over 85F Ambient it seems the aux fan is needed to keep temps in check at slow speeds or sitting in traffic. It has been a crazy hot year here in CO it seems.

I have been tempted to just run water in my bike with some wetter product. I know my system probably hasn't been flushed in awhile. I just have no idea how to bleed these VFRs etc. I can see mine is a mix of anti freeze and water.

 

Anyone ever try drilling a 1/16 hole in the thermostat?
Its a common car trick, I'd imagine it would work with a bike. Plus you have some protection if the thermo goes bad and stays shut.

 

I swapped to Engine Ice when I bought my 2000 and it seems to run about 5 degrees cooler on average I would say. I have used that stuff in most of my previous bikes and all of my dirt bikes and I swear by it

It is good to minus 26 degrees F so you can put it in and forget about it.

 

To slightly switch the heat subject: my "new" 91 VFR 750 seems to radiate far more engine heat than I remember my '92 doing. Per the temp gauge the bike is operating normally. This morning in lo 70F temps I noticed it, but once up to 50-55 no problem. Early this evening with temps in lo-mid 80s...WHEW! Even at 65-70 mph the radiated heat was toasty unless I really spread my legs away from the tank.

If my memory (older age...) isn't failing me; does anyone know definatively whether Honda made airflow changes under the "skin" to reduce the heat one feels by '92? My '03 FJR was a turkey cooker, but my '06 was the coolest (radiated heat) big bike I've ever had. As Yamaha got many complaints their engineers worked long and hard to resolve the issue. DFO

 

Can't speak for the newer bikes, but this is what I did with my 84 VF700 with a VF1000 transplant. I used the VF700 cooling system which was already too small. It was running too hot and was puking when I shut it off! Was running too hot to keep it running at a stop light.

1. Quick flush to get the original coolant out
2. Ran radiator flush for about a 20 mile easy ride (calls for 10 min run time)
3. Let it cool, then dump the flush mix - it had turned brown!
4. Did about 4 more fill-up with clear water and short rides to flush all the crap out - when it starts coming out clear, its good.
5. I used distilled (bottled) water for the last few flush outs. Tap water has too many minerals. The minerals are what build up inside the engine and radiator and cause many problems over the years. Coolant does a decent job of keeping the minerals suspended, but it's best to just keep em' out.
6. Replaced the fan switch with a lower temp (same part # as 84 Honda Civic). You have to replace the factory "spade" wire ends with female "bullet" terminals - no big deal.
7. Fill it up. Used about 4oz of Water Wetter, and topped off with 50/50 pre-mixed coolant. With the remaining residue distilled water from the last flush, I believe I have about a 60/40 coolant to water ratio. Your best "coolant" would be straight distilled water with Water Wetter. However there is no corrosion protection. Honda recommends a 50/50 ration with anti-freeze to prevent the aluminum engine from corroding inside.

I was running down the road with the needle half way up, and on H when I came to a stop! (this never happened with the original 700 engine)

I now run about 1/4 up, and it had not gone over half way up at any stop lights since. Has not puked yet!!

 

I ordered a blower assembly fan from yamaha 2S3-12405-10-00. I don't know how I'm going to get it on the right rad but will fit between the head and the right rad. It might have to go on the outside. That would take some serious mods to the plastic. Something I'm not ready to do.

 

Riding habits can keep things cooler: Shift up earlier, use fewer revs, don't downshift coming to a stoplight but instead glide in using brakes only with clutch lever in, don't accelerate hard, use a minimum of throttle.

Downshifting and using engine braking adds heat to the cooling system.

 

Hi Squirrelman,

I swapped my fan wires and now my 08 VFR cools much faster while i'm moving (>10Kmh) though she is sluggish to cool while stationary. My Viffer still runs hot on twisty mountain roads, however she cools so much better once the fan is on while still riding hard.

regards
Chris

 

DC electric motors can run just fine in reverse but the fan blades may only be uni-directional. The compound curves of the blades may not work in both directions. It still may cool the engine by displacing heat out, but it may be horribly inefficient. I could be wrong, but I went with a fan blade that was designed to rotate a certian way and blow air accordingly.

I could be wrong, some of the fellas at Honda are pretty smart.

 

heres an universal kit made by hayden that i adapted into one of my other bikes. summitracing.com part#HDA-3647