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jamiey
20th June 2008, 22:35
Hi Everyone,
I took my 1991CBR600fm for a little mid winter run today as the sun was shining and i had a day off work - just perfect!!
I noticed when sat in traffic that the temp gauge had risen to almost on the red, luckily I was away riding again with plenty of getting into the radiator before the gauge got right upto the red.
When I got home I left it running on the drive for a while and the same thing, needle (slowly crept up towards hot) so turned it off before it overheated.

I'm new to the forum here so thought i'd try and seek some advice before going out wasting money on bits I don't need

what would be the first thing to rule out?? thermostat perhaps?? fan switch?? or just a simple new lot of coolant - anyone know any simple diagnostic tests to determine the cause, or even is getting to the top of the normal temp range usual with these bikes?? Its my first CBR so not too sure, its fine when i'm riding, no problems whatsoever and the temp is always normal, the problem is after about 5 minutes when stood still

Cheers

Jamie

fatzx10r
21st June 2008, 04:26
did your fan start working when it got hot?

rainman
21st June 2008, 09:28
Water pump?

Also worth checking if the fan comes on - if not your temp sensor (assuming this works on your bike like it does on mine) are probably stuffed. (Or maybe the fan, I suppose - unplug it and put 12V across and you'll soon tell).

When did you last change the coolant?

CB ARGH
21st June 2008, 09:56
I'd say check the coolant levels/condition... Also figure out wether or not the fan comes on once it starts getting hot. You could also check to see if the radiator is dirty which could prevent air from getting to the small bars, which in return would heat up the bars, which means hot fluid cooling the engine... not good! Degreaser does the trick with that ;)

Otherwise it could always be the thermostat, these aren't so dear from what I know (used to work at Repco)... but motorcycle thermo's may be different.

Good luck mate ;)

jamiey
21st June 2008, 12:53
Not sure when the coolant was last done, so i may start with that. The fan did not come on once it started getting hot

Ragingrob
21st June 2008, 13:11
Well if the fan did not come on once it started getting hot, then that could well be your problem. Run the fan from a 12V battery just to see if it works, then check that the wiring to the fan is intact and contacts are clean, if it's still not going when it gets hot then you will need to check the thermostat and just get another one. :2thumbsup

Max Preload
21st June 2008, 14:25
Not sure when the coolant was last done, so i may start with that. The fan did not come on once it started getting hot

Don't start with that - old coolant in itself will not cause overheating unless there is corrosion caused by that and you cannot fix that by changing coolant. Start with manually powering the fan since it didn't come on. If the fan works, check power to the fan switch and the fuse. If there is power, check the fan switch operation. I think that is where you'll find the problem.

Once you've confirmed the fan is again correctly operational, THEN change the coolant.

jamiey
21st June 2008, 20:51
Don't start with that - old coolant in itself will not cause overheating unless there is corrosion caused by that and you cannot fix that by changing coolant. Start with manually powering the fan since it didn't come on. If the fan works, check power to the fan switch and the fuse. If there is power, check the fan switch operation. I think that is where you'll find the problem.

Once you've confirmed the fan is again correctly operational, THEN change the coolant.

Ok, the fan is definetley not coming on when hot, how would i go about manually starting the fan?? I can access the fan switch but haven't been able to take it out yet, connector looks ok...................

rainman
21st June 2008, 21:29
Ok, the fan is definetley not coming on when hot, how would i go about manually starting the fan?? I can access the fan switch but haven't been able to take it out yet, connector looks ok...................

Just trace back from the fan to the nearest connector, unplug that (don't lose the other end into the bodywork), connect 12V and see if it spins. If you don't have a spare battery just pull a pair of test leads direct from the battery. I'm assuming you have some suitable wire, and clamps or clips to keep it hooked up to the battery. Or a suitably gullible person to hold the wires on for you :devil2:

Then, once you know whether it works or not, reconnect to the bit you didn't lose... and let us know what you find out.

jamiey
21st June 2008, 21:36
Just trace back from the fan to the nearest connector, unplug that (don't lose the other end into the bodywork), connect 12V and see if it spins. If you don't have a spare battery just pull a pair of test leads direct from the battery. I'm assuming you have some suitable wire, and clamps or clips to keep it hooked up to the battery. Or a suitably gullible person to hold the wires on for you :devil2:

Then, once you know whether it works or not, reconnect to the bit you didn't lose... and let us know what you find out.

I have a 12v battery charger, will that work?? And just the poistive lead onto the wire coming from the fan right??

rainman
21st June 2008, 21:49
I have a 12v battery charger, will that work?? And just the poistive lead onto the wire coming from the fan right??

Not sure how the charger would like having a fan as a load. Be better to just get two wires from the battery (+ and -, the fan connection should have two wires in the connector.

Do you have any old two core flex from a lamp power cord or similar? That'd work.

jamiey
21st June 2008, 21:59
Not sure how the charger would like having a fan as a load. Be better to just get two wires from the battery (+ and -, the fan connection should have two wires in the connector.

Do you have any old two core flex from a lamp power cord or similar? That'd work.

Thanks for all your help on this one, its driving me mad. It appears that only 1 wire comes from the fan, it has a connector that links it to the fan switch - so if i fully take off the connector there will be 2 wires right for + and -

rainman
21st June 2008, 22:07
Thanks for all your help on this one, its driving me mad. It appears that only 1 wire comes from the fan, it has a connector that links it to the fan switch - so if i fully take off the connector there will be 2 wires right for + and -

No worries, I had a similar problem a while back, different bike though. Hang on while I check a parts catalogue for your bike to make sure I am not confusing the issue.

rainman
21st June 2008, 22:25
Hmmm. Lots of different models of CBR600, I see (sorry, I'm a sportsbike eejit). Closest I can find is this (http://www.cmsnl.com/honda-cbr600f2-super-sport-92-us_model7262/partslist/F++31.html). Page down to get to the fiche image. Hope that's kinda what you have, the fan models change a bit based on year, it seems..

From the picture it kinda looks like the fan has a separate wire with an earth tag, so if your bike looks like the zoomin picture the game becomes how to connect a single wire from the + terminal of the battery to the other (non-earth) tag of the fan.

The only question I have is what that other bit is that's connected in the middle of the assembly. If it's another connector that has both + and - terminals it probably isn't a good idea to pick one and guess cos if you get it wrong you'd be shorting your battery.

Do you have the fan out of the bike, or is it still mounted?

jamiey
21st June 2008, 22:32
Ahh that helps a bit, looks like i'll have to get in behind the radiator, i'll have a go tomorrow and let you know how i get on, thanks for that, much appreciated

rainman
21st June 2008, 22:37
Have fun, I'll also be in maintenance mode, pulling my new tank off and redoing all the hoses, assuming I can find some suitable hose clamps at Repco or Supa Cheap. Leaking tank = bad idea!

rainman
22nd June 2008, 23:13
i'll have a go tomorrow

So, how'd you get on?

I only had to redo the tank once because I didn't tighten the clamps properly enough and it still leaked after I filled it up :Oops:

jamiey
23rd June 2008, 17:09
I've kinda been sidelined, trivial stuff like having to go to work and kids!! I'll let you know as soon as I pick up my spanners!! Did speak to a guy today at econohonda (good on those boys, always helpful and have cheap parts) - got a new thermo switch on its way for $40 (130 at honda), so gonna replace that too while im in there, i'll keep you posted on progress...........

vifferman
24th June 2008, 08:58
You said that five minutes of sitting after running the bike will get the temp into the red - that sounds about normal. The engines heat up pretty quickly when sitting idling. However, the fan should've kicked in.
If the fan switch is like that on most Hondas, to make it go it's just a case of turning the key on and shorting the wire ('earth tag') to ground (some part of the frame or the engine). However, if it doesn't go, that doesn't necessarily mean it's the fan - it may not be getting power to it.
If there's an air lock in the cooling system, that could cause the bike to overheat. I don't know how that's dealt to on the 600, but on the VFR it's a case of taking the radiator cap off, running the engine (but NOT when the bike's really hot!) and squeezing the hoses to burp air out, while toping up the radiator.
If/when the waterpump carks it, it's usually signalled by a leak from the housing (and corrresponding puddle of coolant under the bike). The pumps usually work fine until the seals go, and this is handily indicated by a weep hole built into the housing.
The thermostat's main function is to allow the engine to warm up by stopping coolant circulating until the engine has some heat in it, and to pressurise the cooling system to stop the coolant boiling off. If it's defective, it will either cause the engine to run too cool in cold weather, or will provide insufficient pressure, causing the coolant to be lost (which will cause the engine to overheat).
Last point: you haven't actually said anywhere if the coolant level is fine - the radiator should be full, and the overflow/expansion bottle half full.

Max Preload
24th June 2008, 13:44
If the fan switch is like that on most Hondas, to make it go it's just a case of turning the key on and shorting the wire ('earth tag') to ground (some part of the frame or the engine). However, if it doesn't go, that doesn't necessarily mean it's the fan - it may not be getting power to it.

Like he said, earth the wire from the fan thermo switch if it's a single wire, but if there are 2 wires short them together.

If you want a hand PM me.

NOMIS
24th June 2008, 14:01
Hi Everyone,
I took my 1991CBR600fm for a little mid winter run today as the sun was shining and i had a day off work - just perfect!!
I noticed when sat in traffic that the temp gauge had risen to almost on the red, luckily I was away riding again with plenty of getting into the radiator before the gauge got right upto the red.
When I got home I left it running on the drive for a while and the same thing, needle (slowly crept up towards hot) so turned it off before it overheated.

I'm new to the forum here so thought i'd try and seek some advice before going out wasting money on bits I don't need

what would be the first thing to rule out?? thermostat perhaps?? fan switch?? or just a simple new lot of coolant - anyone know any simple diagnostic tests to determine the cause, or even is getting to the top of the normal temp range usual with these bikes?? Its my first CBR so not too sure, its fine when i'm riding, no problems whatsoever and the temp is always normal, the problem is after about 5 minutes when stood still

Cheers

Jamie

If you dont have a clue and want to do it your self start with the elimination process. coolant .. and make your way towards other things. hopefully something simple and habn't cracked the gasket or anything

Max Preload
24th June 2008, 14:18
If you dont have a clue and want to do it your self start with the elimination process. coolant .. and make your way towards other things. hopefully something simple and habn't cracked the gasket or anything

The fact the temperature gauge registers the overheating is a pretty sure indication of sufficient coolant - senders don't work well in steam. Besides, one would assume that coolant level is the first thing poster #1 would have checked.

NOMIS
24th June 2008, 16:19
The fact the temperature gauge registers the overheating is a pretty sure indication of sufficient coolant - senders don't work well in steam. Besides, one would assume that coolant level is the first thing poster #1 would have checked.

Correct you are , and yes you would hope so wouldnt you.

jamiey
24th June 2008, 19:32
Thanks guys, loads of helpful advice, but alas another day spent in the garage to no avail, coolant is fine and ive replaced the fan switch, ran the bike for a bit then let it stand and it took about 10 mins to get near the red (pretty normal i'm sure). I let it get into the red mark on the temp gauge - still no fan!!! So i turned it off to prevent any damage. Im not too bothered as its ok under normal conditions and i tend not too sit in traffic anyway, its just bugging me now and i will have to get it sorted before those long hot summer runs (seem far far away at the moment). Might just bite the bullet and take it in somewhere..............

jamiey
24th June 2008, 19:43
Just done viffermans quick test on the fan (thanks) and it works fine came on straightaway, so fan works, coolant is good, new fanswitch, next??

Max Preload
24th June 2008, 23:22
Did speak to a guy today at econohonda (good on those boys, always helpful and have cheap parts) - got a new thermo switch on its way for $40 (130 at honda), so gonna replace that too while im in there, i'll keep you posted on progress...........


Just done viffermans quick test on the fan (thanks) and it works fine came on straightaway, so fan works, coolant is good, new fanswitch, next??

I'm confused. From what I understand you've fitted the 'new' fan switch from Econohonda and it still doesn't oerate the fan automatically? You didn't put thread tape on the swtich thread, did you? You can't do that with a single wire system (and don't need to on a thermo switch anyway - they're a parallel thread with a o-ring generally). A single wire system relies on grounding through the thread to the radiator to the chassis.

When you earthed the fan switch wire which then started the fan, where did you earth it - radiator or frame? Does the fan work when you earth the wire through the thread on the radiator? Check for continuity between the radiator and the frame with a multimeter set to resistance.

jamiey
25th June 2008, 09:50
I earthed the fan to the frame, no thread tape on the switch.........

Max Preload
25th June 2008, 11:43
I earthed the fan to the frame, no thread tape on the switch.........


Does the fan work when you earth the wire through the thread on the radiator? Check for continuity between the radiator and the frame with a multimeter set to resistance.

You're making it really difficult to establish anything concrete by answering so selectively and briefly.

jamiey
25th June 2008, 20:08
Sorry Max, ok here goes. The fan works when i ground it to the frame, but when i run the temprature up to almost the red i'm getting no ground through the thermoswitch, therefore the fan isnt coming on automatically. I tried grounding the fan by touching it against the radiator but nothing happened

Max Preload
25th June 2008, 20:45
If you're sure you got a good connection on the radiator (not a painted bit) and the fan still failed to operate, you need to check for continuity between the radiator and the frame. Do you have a multimeter?

jamiey
25th June 2008, 21:01
If you're sure you got a good connection on the radiator (not a painted bit) and the fan still failed to operate, you need to check for continuity between the radiator and the frame. Do you have a multimeter?

No haven't got a multimeter, might go and buy myself one tomorrow. I tried to earth the switch on the bottom of the radiator, it looked like a nice unpainted metal area. I wasn't keen on taking out the thermswitch again as i've replaced the coolant 3 times already over the past few days trying to sort this out.

Its not really that important i suppose as i never sit in traffic or leave her running, but it seems this problem has become a personal mission for me to sort out, anyone else had that feeling on such a niggly problem - its driving me nuts!!

Max Preload
25th June 2008, 21:16
A multimeter is a handy thing to have, and they're cheap as chips for models with basic functions.

You could just fit a manual switch but if that's your only switch you need to remember to keep a close on the gauge. I have both the thermo switch and a manual one in parallel with a red warning bezel which lights anytime the fan is operating - either automatically of manually.

My thermo switch crapped out in city traffic about a year back and although I replaced it, I figured since I'm here...

jamiey
25th June 2008, 21:23
A multimeter is a handy thing to have, and they're cheap as chips for models with basic functions.

You could just fit a manual switch but if that's your only switch you need to remember to keep a close on the gauge. I have both the thermo switch and a manual one in parallel with a red warning bezel which lights anytime the fan is operating - either automatically of manually.

My thermo switch crapped out in city traffic about a year back and although I replaced it, I figured since I'm here...

Thanks mate, i had thought about that (a switch) i read some instructions somewhere on a website for the exact same thing on a CBR, I take it i just run the single wire to a ground point on the frame with a nice neatly posistioned switch somewhere along the way??

Max Preload
25th June 2008, 21:43
Yeah, but your switch needs to be waterproof and handle the current the fan draws if you do it like that, in which case you'll most likely need a relay unless you want a big ugly switch.

Here's what mine looks like:

jamiey
26th June 2008, 15:15
Problem solved guys, thanks. A quick trip to jaycar - a switch and other bits cost me less than $10. Grounded the wire to the frame with a nice neat waterproof switch on the fairing, works great. At last, wish i'd just done that in the first place. Just gotta remember to turn it on and off now when in traffic etc

Max Preload
26th June 2008, 19:25
Out of interest, does the manual switch operate the fan with the ignition off, because my thermo fan switch will still run the fan regardless of the ignition being on or off - it's always powered.

jamiey
27th June 2008, 13:03
Out of interest, does the manual switch operate the fan with the ignition off, because my thermo fan switch will still run the fan regardless of the ignition being on or off - it's always powered.

No only works with ignition on