The water pump ciculates water within the engine. As the engine comes up to temperature, the thermostat will bypass water through the radiator. So, you won't really see much circulation through the radiator at temperatures below 160F, the theromostat opening temperature.
I do know that it doesn't take much of a high idle to cause your R1 engine to overheat. I ran my idle at 1500 rpm for a bit because of an annoying miss while accelerating from a stop. At the normal 1200 rpm, the fans would kick on as they should at 220 and quickly bring the engine temp back down to 210 even during the summer. With the idle at 1500 the fans would barely be able to maintain 225F at air temps in the region of 50ish degrees F.
Hello all. I too have this problem on my 2004 R1 here in Oz.
Last year I had a coolant leak which progressed to a stage that it come out as fast as I could put it in. The bike would idle extremely high a few times just before I stopped riding it, which I thought had something to do with the low coolant level causing a sensor to adjust the idle abnormally.
I stripped the bike down, the o-rings in the water pump were bad, so I ordered parts from my local bike shop (around $600 for the pump and seals, to come from Japan). I just finished putting the bike back together after waiting 7 weeks for the parts.
It fired up alright, but once it warms up to the temperature where the idle should slow down, it slowly rises instead, thus causing the temp to rise quickly also. If I give it some throttle input the revs won't drop normally, because of the high idle.
Does anyone know what might cause this, a sensor, a bad ignition computer, the thermostat (which tests ok). I unplugged the PC3 but that didn't help. I guess I could get the local yam shop to swap a few sensors to fault find, but I'd rather check if someone else has had this problem and knows what caused it.
I had squeezed the tubes to remove any air that could be in the system when I filled with yamalube coolant. I still had this problem.
What I did to fix it was take the radiator cap off again, squeeze any tubes I could that were part of the cooling system, but this time I did it when the bike was hot, carefully as to not burn myself on the exhaust. I think the air must have been around the thermostat causing it not to heat up properly and alas open up to pump coolant around quick enough, well that's my guess.
I just rebuild by engine and now my bike is doing this exact problem. The bike runs fine, but when reving the engine. It will rev up quick, but float a little and then come back down. Also it only takes a few minutes for the bike to get to 250 degrees. I have to have air trapped somewhere. Yamadogfj1200 did you ever figure this one out?
Hello barryely, did you read my last post, running the bike until it is hot, removing the radiator cap carefully and squeezing any cooling system tubes multiple times to try and force air out. Then put the cap back on and try again with the bike running. This cured mine. Worth a shot.
I have had similar problems whenever I have removed the radiator and needed to put coolant back in the system.
The way I removed the air in the coolant system was to fill it up, put the cap on. Tilt the bike as far over as possible to each side remove the cap and fill up again. Repeat until there is no change in coolant level after tilting the bike.
Then start the bike and squeeze the hoses between the radiator and the engine to push the water into the water pump. This usually does the trick.
To test if the water is flowing you can check the temperature of the radiator, it should be hot all over when the engine is.
well tilting the bike from side to side (handle bars touching ground) did allow be to put maybe another ounce of coolant in. I'll get a second person to squeeze the hoses while I have it tipped over. The bike still heated up to about 250 in maybe 2 minutes. The water temp at the radiator only got up to about 110 on both ends, but then as soon as I turned the bike off the temp in the radiator jumped to 150-180.
I am having the same problem it sounds like. I had to replace my radiator a while back and ever since then it has gotten hot. But recently i have had the problem where it will get up to 250F. When I come to a stop i notice coolant leaking from the overflow tube on the left side of the bike. The coolant level in the resivoir is in between min and max before i start riding. Why would it overflow? I have replaced the thermostat, made sure both cooling fans are running, replaced the radiator cap... I am out of ideas. I will try to squeeze the hoses like stated above and let you all know if that works. If anyone has any other ideas please let me know as this is very very frustrating.
I solved my problem. My engine had just been rebuild. Not sure as to why but my chain had fallen off the oil pump/water pump. I think it was been i was installing the cluch basket. The engine was still usable but my head and cams were trashed with no oil flow.
Look in your sight glass adam and make sure its moving oil when you start your bike. If the oil pump is turning the water pump should be as well. The only other thing is air in the system or a stuck closed thermostat.
I went home and looked through the sight glass and started the bike and the oil is being pumped through the engine. i also decided to take the thermostat out and test it in boiling water and it opened up at 155F. I drained the coolant, im using engine ice by the way, and it looked clean, its only a 1000miles old or so. I strained it to make sure to take out any debris if any and refilled it. Squeezed the tubes to get out any air pockets and ran it with the cap off to get air bubbles out. i put the cap on and let it heat up to 221(fans came on) in my basement then it cooled down to 212(fans kicked off). let it do that a few times and no coolant leaked out from the resivoir. Next day i took it out for a ride to further test it. 95F outside and got it hot, stopped and let it sit running and it got up to 221 fans came on and coolant started comming out of the overflow again and the temp slowly started to rise above 225. i am out of ideas any help?