85 VFR700F cooling issues

Hello all,

I recently purchased an 1985 Interceptor with 56k miles.
When I purchased it the owner (third owner) told me that the upper radiator needed to be replaced.
Most of the fins were either bent or rusted. The bike lived outside of a garage near the ocean.

I found a sweet upper radiator on ebay and did the swap. I used the old coolant since the previous owner had just replaced the coolant.

I too live near the coast and have been commuting back and forth to work (15 miles each way) with zero problems (temps being under 75 degrees)

But now summer is here and on my way home today the bike got hot. Did not overheat, but wanted to at idle.

I have put in a manual switch for the fans, and run them as soon as the bike warms up.

The lower radiator looks good and I have no leaks.

I pulled the thermostat out, and it still heats up after 20 minutes of riding.

Anyone know where I should go next???

I plan on changing the coolant myself, along with an oil change this weekend.
Other than that, I am baffled.

Any help would be much appreciated.

Regards,

A vintage honda lover

 

I would make sure that the water pump is working properly, & that you have all the air bled out of the system.

 

Defo check the pump...
Maybe the new rad looks OK on the outside but is scaled up in side. Try replacing the coolant with 50/50 white vinegar/dist water, running it up to temperature then flushing it. (from the Engine Ice website)
I'm doing mine tonite.
cheers RIch

 

Re-check coolant level under the rad cap (engine cold) and don't run without a proper thermostat !!

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Check the coolant itself with a hydrometer. It's my understanding (I may be wrong) that too much antifreeze to water ratio will hurt the cooling capability of the coolant mix.