03 954rr 13K miles

Today while riding I noticed coolant leaking. I pulled over and saw that the overflow bottle was so full it was leaking out the overflow tube near the top of the cap. I popped the cap off and could hear the coolant bubbling as it flowed back into the radiator. It went back to the normal full line of the bottle. I started it back up and let it heat up to about 218 or so. The coolant level didn't rise again. This is the second time this has happened. It doesn't happen all the time. I have a 60 mile commute one way each day, so it was definiatly warmed up, but not running abnormally hot. Even in rush hour traffic it never got above 235. I don't think it is just as simple as being overfull with coolant. If it was it should have overflowed when I started it back up and let it idle till the fan kicked on @ about 215.

Any ideas?

You might have had a big bubble of air in the system. Bleed it out. The manual tells you how. Might be worth a try..

that and also check the thermostat

here's the manual to download

http://gntbldr.com/HondaManuals/954.zip

Also when was the last time that you changed your coolant?

235 is way hot, imo. definately check the thermostat.

235 is very hot. mine has never seen above 215 sitting in 90 degree traffic!!!!!! change the coolant.....

Just changed the coolant toward the end of last season. Switched to Engine ice. My 954 has always run hot. Before engine ice I hit 250 in a traffic jam before I got moving, then it cooled down right away. I guess I will check the termostat as suggested. When I am running at highway speeds it will usually cool down to operating temp at 180. Just warms up quick when in slow traffic.

Just changed the coolant toward the end of last season. Switched to Engine ice. My 954 has always run hot. Before engine ice I hit 250 in a traffic jam before I got moving, then it cooled down right away. I guess I will check the termostat as suggested. When I am running at highway speeds it will usually cool down to operating temp at 180. Just warms up quick when in slow traffic.

most bikes are like that, engine ice inst the best stuff for your bike. if you change out your coolant at the end of every season just run water wetter and water in your radiator. just make sure it doesnt freeze. im not sure if honda makes a lower thermostat you can put in the bike. but that could always be an option. as for the overflow, it does sound like air in the system. do you do a lot wheelies??? jw if that could have an effect.. i did the occasional wheelies but never had problems....