Chriswood30 Posted May 27, 2020 Share Posted May 27, 2020 Hi guys, firstly thanks in advance for any help. So I have a 2001 bird which is having a bit of an overheating issue. So if I have the bike at idle in the garage temp will rise to around 102 deg, fan kicks in and goes down to around 94 which is perfect. Out on a run at a decent pace between 87 and 105, again temp perfect. Now after the run i leave the bike to idle on the drive, fan is running but now the temp starts to get hotter and hotter all the way to 117 deg and climbing that's when its turned off. Has anyone experienced something similar, I've ordered a new radiator cap and thermostat which arrive this week. Your thoughts would be appreciated Quote Link to comment Share on other sites More sharing options...
XXitanium Posted May 27, 2020 Share Posted May 27, 2020 For consideration... Quote Link to comment Share on other sites More sharing options...
superhawk996 Posted May 27, 2020 Share Posted May 27, 2020 Any engine will commonly get hotter if left to idle right after being under load, but yours is going higher than I think it should, assuming that you have some cruising time between the high speed run and stopping in the driveway. If you made a fairly quick stop after being at high speed it could be normal. A bad thermostat is unlikely to be the cause, a bad cap not holding pressure is possible. Quote Link to comment Share on other sites More sharing options...
SwampNut Posted May 27, 2020 Share Posted May 27, 2020 I've often noticed temps climb on all sorts of vehicles after high speed or high load (towing), then going to idle. I agree on thermostat and cap, also would add possibly old/dirty coolant, oxidation in the system, basically routine cooling system stuff. Also, what is your coolant type/mix ratio? Quote Link to comment Share on other sites More sharing options...
Furbird Posted May 27, 2020 Share Posted May 27, 2020 You should take it to the dragstrip. I'd come in from a pass and have two vortex-style fans wide open pointed at the radiator. That sucker was thermonuclear without the forced air assistance. Birds run hot. Quote Link to comment Share on other sites More sharing options...
ptxyz Posted May 27, 2020 Share Posted May 27, 2020 (edited) i've seen 238 fahrenheit (114c) on a very hot day in slow detour traffic. i hear the ecu will shut down the party at 250f. be sure your radiator fins are in decent shape and the inside's free of scale, new thermostat's good insurance. you can also see a few degrees of cooling by reving the motor up to a few thousand rpms. a few here have added another cooling fan. i'd want to know they don't take up all your charging voltage at idle... what you're seeing sounds pretty normal though. as has been noticed, these bikes run hot without airflow. Edited May 27, 2020 by ptxyz Quote Link to comment Share on other sites More sharing options...
Chriswood30 Posted May 27, 2020 Author Share Posted May 27, 2020 Hi guys, really appreciate you suggestions on this. Was doing the same prior to coolant change, followed the book and bled the system, all ok, checked again after run still fine. It was ok prior to not using it much last year. Had the rad off all ok so I'm doing the rad cap as I see that a lot on bb forums, maybe thermostat if not I guess water pump is next but from what I read the failure rate on them is small. Brill bike and love being part of this community even if it starts with a problem lol Quote Link to comment Share on other sites More sharing options...
XXitanium Posted May 27, 2020 Share Posted May 27, 2020 1 hour ago, Chriswood30 said: Brill bike and love being part of this community even if it starts with a problem lol ...you pay for you plant with £s? Quote Link to comment Share on other sites More sharing options...
Chriswood30 Posted June 14, 2020 Author Share Posted June 14, 2020 Ok so changed coolant, rad cap and thermostat and no change. All runs perfect out on the road, temp was at 103 deg c after a ride out and a short run through town before home, left it at idle on the drive and 104, 105 etc all the way up to 117 deg or 242 deg f before shutdown. Anyone tried wrapping the exhaust to bring the temp down? Cant think of much left to change Quote Link to comment Share on other sites More sharing options...
fizzy Posted June 14, 2020 Share Posted June 14, 2020 Fan motor may be dying once it gets hot and/or old wiring giving the fan low voltage. Also, possible radiator damage, fins etc. As Furbird says above, these bikes run hot, engine hot, transmission hot, frame hot, everything hot. "A short run thru town" is not enough to cool it off. Finally, what is battery voltage at idle when the fan kicks in? Free tip, raise your idle speed a little, this will raise the voltage some and speed up the water pump. FYI: some on here have added a second fan. Quote Link to comment Share on other sites More sharing options...
Furbird Posted June 14, 2020 Share Posted June 14, 2020 Birds run hotter and hotter at idle. You have to remember that water pump has a large rev range it has to remain functional in so the sacrifice was made at idle. I have a throttle lock on my bike and sit it at about 1500 to assist in cooling if I'm trying to cool it down. At a red light (and I live in the deep south where it hits 95 degrees with 95 percent humidity fairly regularly) I will put a little throttle in it to raise it up to that 1500-1800 range if I know the light will have me sitting there for a while. Exhaust wrap is asking for trouble on a street bike as no matter how well you wrap them they will trap moisture and accelerate corrosion/rust. Quote Link to comment Share on other sites More sharing options...
superhawk996 Posted June 15, 2020 Share Posted June 15, 2020 I haven't tried a wrap, but Jet Hot coating dropped the header tube temp from about 400F to 300. I didn't experiment enough to know if it would change the engine temp, but it should help some. These do get hot at idle, but won't overheat unless something's wrong. If they did there would have been a big piss up with Honda a long time ago. And humidity makes a person feel hotter but doesn't make an engine hotter so that 95% thing Fur mentioned is irrelevant. Fizzy brought up some things worth checking. Also, the gauge could be lying so checking the engine temp with something else would be a good idea. I use an infrared thermometer and check the thermostat housing to verify temps. Quote Link to comment Share on other sites More sharing options...
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