I was out puttering around yesterday, I'm still getting used to my 91 1000F, so I'm not hard on it. It was about mid 80's yesterday and I rode down into town. While sitting at lights I noticed the temperature climbing awfully close to the red line. A friend of mine said that it's common and just so long as it doesn't go into the red, I have nothing to worry about. Well, after about 10 minutes of city riding it went into the red, so I left and got back on the highway to cool it down, but it still kept creeping up toward the red line every time I had to stop.

I'm planning on doing a coolant system flush soon hoping this will help, is there anything else I need to look out for? Oh, the fan sounds like it's kicking on and running okay too.

Normal running temerature for it seems to be about the middle of the gauge.

 

Is the fan coming on

 

Yes, it seems to be. I've noticed though that sometimes it's running after I shut it off (key still on)when it's about 3/4 toward the red zone, and other times that if it's closer to the red zone that and I shut it off and the key is still on that it sometimes is not running. Maybe the temp sensor is going bad?

 

One does not puttering on a CBR

I would be change the coolant and give it a flush, sounds like theres is another issuse

 

MarkR is right they have a 10.5 rev limit. Check the radiator fins bugs and dirt + the oil cooler

 

I was using the term "putter" jokingly, but being a new rider, I don't tear up the asphalt on it like you more experienced ridersdo/can. Hell, I think I've barely ever had it above 6k rpm yet. I'm still slowly trying to get used to its power so that if I ever want/need it, I can handle it without killing myself.

I'm beginning to think that I have an erratic temp sensor for the fan and possibly junk in the cooling system. I rode it home from work yesterday and when I was getting ready to put it away, it started overheating and boiling. I turned the key on (didn't start it) hoping the fan would kick on and it didn't (should it have?). By the time I got it put away it was spewing antifreeze from the resevoir which didn't look as bright green as new antifreeze, but didn't look bad... could definitely use a flush though.

I didn't ride it today and I don't want to until I get this issue figured out. The fins in the radiator and oil cooler look good and mostly clean (not many bugs or other junk).

Is there a special way to flush the systems in these bikes? Or is it, drain the antifreeze, add water, start it and let it run to operating temperature, drain it, add water and keep repeating until whatever comes out is clean and clear? (This is what I've done on my vehicles in the past).

 

You might want to check for leaks in the cooling system. I had a pinhole leak in the hose joint (#20 in the attached) that wouldn't leak until the temperature rose and the pressure built up. This caused me to lose coolant and temps would rise into the red. It took me a couple of days and a lot of anguish before I figured things out.

[IMG]local://upfiles/16639/E614FAD45D9841A89EF1ACB8E33A3665.gif[/IMG]

 

Thanks for the illustration. So far in the month I've been riding it, the coolant level seems to be holding well (via checking the overflow tank), so I don't think I have any pinhole leaks, but you never know. I'll check that as well anyway just to be safe.

Woo Hoo! I just noticed that I became a senior member!

 

Typically the temp gauge will get to just below the last line before the red zone on a hot (80+) day in city traffic. However the fact the your normal highway temp is in the middle indicates to me that there is something else going on. Others have suggested changing the coolant and checking for restrictions in the radiator. If it continues after you've done those, I would change out the thermostat with a new stock Honda one. They are a few bucks more, but they actually fit correctly.
My temp on the highway on even the hottest days is a about the quarter mark. Far less the the half mark yours is reading.

 

I figured it shouldn't be running as hot as it has been. Thanks for the info. I'm going to start with flushing the system and go from there.