cooling system feedback

I was wondering if I could get a little feedback. I have an '86 750 that stays in the bottom third of the temp range on the highway but at slower speeds like through a neighborhood the temp climbs rapidly and stays in the upper third of the temp range. Is this normal? Thanks in advance for any help. This is my first water cooled bike.

 

Thermostats can be a cheap solution to control temperature, but the honda version is mostly crap.

 

Thanks kennybobby but what I'm trying to find out is if this is normal. Any feedback on what your bike usually shows temp wise under what conditions would be very helpful.

 

When they stick in the open position, the engine runs cold and seems to never warm up--the temp gauge reads in the low region. When it sticks closed the opposite occurs--it runs hot and the gauge indicates high.

Yours may be somewhat working but going in the wrong direction or sticking along the way and causing a delayed response.

If working correctly it should warm up to temp and then hold there no matter what the speed.

OR, maybe the problem is in the gauge itself, or in the temp sensor, and not the thermostat--might want to run an electrical check first before pulling parts...

 

Thanks again Kennybobby. I had assumed that the temp should stay pretty consistent but wasn't sure what the norm was for these machines. This bike is new to me and I wouldn't be surprised to find out that the thermostat was the issue.

 

I can't speak directly to your year VFR, but my 2001 does vary somewhat in operating temperature, and it seems to be common among the later VFRs with digital temperature gauges that they run about 180F at highway speed and warm up to 220F in city traffic, at which point the fan comes on. The same seems to happen with my VF750 Magna, but since it doesn't have a temperature gauge, it doesn't cause the rider to worry.

 

Thanks for the info H3nry. It isn't overheating even in our Texas weather but I'm beginning to think the thermostat is stuck in the open position. I wonder if anyone adapted a gauge with real numbers to these older viffers?
By the way, just went through your part of the Lone Star state last weekend.

 

Coolant temp will bottom out at the thermostat's opening temperature, 175-180F on most Hondas, at high speed with a lot of airflow. If your temp gauge drops below the normal range cruising at 60-70 MPH, then the thermostat may be stuck open. My guess is your bike is normal. Since bikes don't have a fan running constantly, they heat up in traffic. Sort of backwards from cars. You don't really need to worry about engines running too cool in Texas in summer.

 

My 86 runs the same as you describe. I think it's normal, remember you've also got that oil cooler that's going to be aiding in removing engine temp while you're moving at a good clip.

 

My 06 Interceptor runs cool while moving and toasty while in traffic. 21k miles and it has always done this. Last year I flushed the cooling system with distilled water and refilled with Honda pre mix coolant as part of normal maintenance and there was no change in temps. It was good to get the nasty old coolant out (I was overseas for 3 years).

For example, 95F out and it'll stay at 185F until I hit stop and go and then it'll climb to 220F and the fans will kick on and push the temp back down to 200F. As soon as I start moving again, it drops.

I think what you're describing is normal.

 

My 2003 does the same, except I use manual switch on fans to keep it under 200.

 

Thanks for all the input guys. Feeling a bit better about the system after hearing this.

 

My '86 behaves exactly as you describe. I think your bike is doing what it's supposed to do.