Is it normal for the temp to go from high to low rather rapidly? It always comes down....but seems to go all the way hot at times. Just want to make sure that's normal. The fan will kick on when I'm stopped, and that brings the gauge down, too. Just getting used to a new bike and want to know what's normal.

Thanks,

Warner

 

I'm going to flush and replace the coolant......with Engine Ice. See if that helps. I've read these things can run hot, and the way it's fluctuating makes me think it may be a little low on coolant.....going to do that before I ride anymore.....after riding home from work today, anyway....

Warner

 

Trying to find how much coolant this thing takes....don't know if a half gallon will do it or if I need more......tough to find a spec on this!

Warner

 

Found it. 2.75 us quarts, plus .42 quarts in the reserve tank. A gallon of Engine Ice is on order. Hope to tackle that this weekend.

Warner

 

Normal....
There are many post here about that subject. General consensus is, (myself included) temp gauge goes up to 3/4 scale when stopped in traffic. The fan kicks on and holds at around 3/4 scale. Upon hitting the open road again, the needle drops back to 1/4 scale and holds steady. Normal...

At one time the 1kF was the fastest production bike before the CBR1100xx came out. I guess Honda wanted to shave weight and decided a smaller radiator was the trick.

If you have she open, replace the radiator cap and thermostat as well.

 

When I first got my CBR, it was still pretty cold outside, so I experienced no issues with over-heating. But the first time I rode it in hot weather, the Temp Gage shot up into the Red Zone. It freaked me out. I decided to examine the system, as well as drain and flush it. Good thing I did. I've never seen coolant look like that before. Very odd color, and strange viscosity. I drained it out completely, and removed the radiator to check it out thoroughly. I carefully blew out all the bugs and other crap lodged between the cooling fins. I cleaned it gently with soap, water and a soft bristle brush. Checked all the hoses. Reinstalled everything and flushed the system with water and vinegar. Put in fresh coolant (safe for aluminum) with Distilled Water. I took it for a long ride, and everything seemed fine...until I got stuck in some heavy traffic. It started over-heating again. I did hear the fan kick on, so I didn't think that was the problem. But I thought perhaps the fan switch was intermittent or defective. Some trouble-shooting indicated that the fan switch was acting oddly, so I ordered a new one. Put it in, took it for a ride, got stuck in traffic again, and it began over-heating again. I looked at everything again, and this time discovered that I had accidentally left off the fan ground wire which attaches to a mounting bolt near the top of the radiator. D'OH!!! Once I hooked that up, all was well. My gage rarely hits the halfway point. It's usually right around 3/8 of full travel. Only when it is extremely hot outside and sitting in stopped traffic does it ever get to the halfway mark.

So, flush coolant with water and vinegar, make sure radiator isn't blocked with crud, use distilled water with new coolant. As long as the rest of the system is working correctly, you should see much cooler temps.

 

EXACTLY what I did today! Drained it, flushed it with distilled water until it came out clear. Then filled it with distilled water, ran it for 10 minutes to heat it up. Then let it cool and drained it again. I left the drain bolt out and began filling it with Engine Ice, leaving the drain bolt out until the fluid coming out was pure blue (color of Engine Ice), then put the drain bolt back in and filled up the radiator. Siphoned the green coolant out of the reserve tank and filled that properly with Engine Ice. Started it up and guess what? It did EXACTLY what it's supposed to go. Warmed up gradually, fan kicked on after it was about half way warm, and the gauge never came close to being pegged. Then I went on about a 40 mile ride, in all kinds of conditions.....stop lights, highway, 30mph residential. The bike ran PERFECTLY and the cooling system worked exactly as it should. Thanks for the help here! I'm psyched. This bike is AWESOME. It's everything I'd hoped it would be...and exactly the type of bike that I wanted. Here's a photo of it in front of my parents house, which is about 20 miles from my house.

Warner

 

I see the warner tag on your post. That is my last name. Is that what yours is. I have an 88 with a 90 or 91 motor I put in it.

 

Welcome to the forum Mr. Warner.

I have flushed mine twice and it made no difference on the needle. I have been thinking the fan switch may be coming on to late.

 

I recently flushed mine, new radiator fluid, pressure washed carefully the radiator grill.

I have ordered a new radiator cap and thermostat.

While I wait for my used stator to come. About all I do till then is charge battery and ride for about 30 minutes.

A few more days.

I'm actually suspecting the heat ruined the stator in the first place. Because before the stator failed, the bike would get close to the red at stop signs in town.

After reading a few posts, I did the flush and new fluid.

Which only helped a little. I was still 3/4 over on the gauge. And normal was in the middle of the gauge after 1 hour of riding.
But now that I'm in limp mode until the stator comes. I hope to ensure the bike is running cooler.

Ryan