Coolant/radiator system?

[oracle]

I brought a VTR a few weeks ago, found it was overheating a bit and yet there was still enough coolant in the overflow. However when I took it in for a service, the guy said it was low and topped it up. Since then it has been peeing coolant through the overflow hose after rides (about 8 times). I took the tank off this morning to look at the radiator itself and despite the overflow reservoir being more than full, upon opening the radiator cap I could not see any coolant. Is my google research right in that this should be completely full? And I therefore really need to get onto this? Any suggestions? I can do some basic maintenance but my last bike was aircooled and I am a) disheartened that this problem wasn't picked up when I paid for the mechanics to have a look at it and b) really don't have the money to pay for professionals to do the work atm

[bluebird]

Is the fan working?

[FJRider]

Check the tube to the coolant reservoir has no leaks (or blocked)... ie: NOT sucking air.

As I understand ... when hot it pushes water out of the radiator to the reservoir, and as it cools ... sucks it back to the radiator.

[oracle]

Check the tube to the coolant reservoir has no leaks (or blocked)... ie: NOT sucking air.

As I understand ... when hot it pushes water out of the radiator to the reservoir, and as it cools ... sucks it back to the radiator.

That was my understanding as well. Which is why it makes sense that if overfilled would be peeing the coolant out of the overflow hose. However if blocked, would it not have that happening so wouldn't be doing so? And if there were holes in the line wouldn't it be leaking from there (which it is not)

[oracle]

Is the fan working?

It is not overheating any more, stays at about 1/4-1/3 temp when running now and they checked the fan was going when it was serviced etc

[FJRider]

That was my understanding as well. Which is why it makes sense that if overfilled would be peeing the coolant out of the overflow hose. However if blocked, would it not have that happening so wouldn't be doing so? And if there were holes in the line wouldn't it be leaking from there (which it is not)

Water (under pressure especially) takes the easiest route ... obviously not blocked, but as the engine cools (gradually) it sucks it back into the radiator... if it sucks a little air too, it may result in less water in the radiator each time it cools.

Just ensure the outlet FROM the radiator (inside the coolant reservoir) is below the water level in the reservoir at all times ...

[NinjaNanna]

Radiator cap is actually a 2 way valve. Check to make sure it isn't jambed shut in the "suck" position. If it is then it will be able to push the expanding water out, but not suck it back in as it contracts while cooling

[oracle]

Radiator cap is actually a 2 way valve. Check to make sure it isn't jambed shut in the "suck" position. If it is then it will be able to push the expanding water out, but not suck it back in as it contracts while cooling

How am I supposed to do that? the water doesn't exit to the reservoir via the cap in my bike's case though, the hose comes out further down248194

[FJRider]

ALSO check the thermostat ... done by taking it out and seeing if it's completely shut when COLD ... Put it in a pot of boiling water and make sure it OPENS FULLY...

Not opening fully will cause overheating too ... (usuall shown up by heating up on the gauge quite fast)
Not closing will make it run cold, or take ages to heat up.

If it's (the cooling system) working properly (well at least seems to) Keep a close watch on the fluid levels before/during/after ... use. (If its working ... dont fuck with it) and go from there, regarding the symptoms you find.

[oracle]

ALSO check the thermostat ... done by taking it out and seeing if it's completely shut when COLD ... Put it in a pot of boiling water and make sure it OPENS FULLY...

Not opening fully will cause overheating too ...

It is not overheating anymore, was only overheating because the radiator was low on coolant which it may be heading to now. The only problem appears to be that the coolant isn't returning to the radiator from the overflow reservoir

[FJRider]

The only problem appears to be that the coolant isn't returning to the radiator from the overflow reservoir

Then it would seem the return hose IS THE PROBLEM.

REMOVE it and check for leaks and all seals, are sealing ... and the end of the return hose is ALWAYS below the water level.

[oracle]

Then it would seem the return hose IS THE PROBLEM.

REMOVE it and check for leaks and all seals, are sealing ... and the end of the return hose is ALWAYS below the water level.

I will have to try to find time to do this (and figure out how) but I still have the question that if it was leaking or not sealing, would the coolant not be coming out from here when hot?

[FJRider]

I will have to try to find time to do this (and figure out how) but I still have the question that if it was leaking or not sealing, would the coolant not be coming out from here when hot?

NO ... as I said in an earlier post ... water takes the easiest path. The hose to the coolant resevoir is NOT a pressure line. So leaks are NO ALWAYS obvious ... Clamping the reservoir line end and idle/run to increase engine temp may show where the problem is ...

A temporary solution is topping up the radiator prior to rides.

[oracle]

NO ... as I said in an earlier post ... water takes the easiest path. The hose to the coolant resevoir is NOT a pressure line. So leaks are NO ALWAYS obvious ... Clamping the reservoir line end and idle/run to increase engine temp may show where the problem is ...

A temporary solution is topping up the radiator prior to rides.

OK mate, calm down I'm fairly new to motorcycling and very new to any sort of mechanical stuff and just trying to understand, hence asking for HELP

[oracle]

Thought about it more and looked into how radiator caps work (as I said, I am very new to thinking about the mechanics of a vehicle) and it is a possibility that this could be stuffed. Is there anyway I can check this myself (without the special pressure equipment) or how much would a replacement one approx be?

[Winston001]

Can't help you Oracle but good on you for asking. You are in the right place. You are wise to recognise you are on a learning curve and there are lots of good people here to help.

FJ Rider wasn't telling you off, simply ensuring you understood that temporary fixes are no solution.

[bogan]

When you take the cap off, can you hear it sucking in air?

Replacement rad cap shouldn't be too much, <50 bucks I'd hope.

[oracle]

When you take the cap off, can you hear it sucking in air?

Replacement rad cap shouldn't be too much, <50 bucks I'd hope.

Didn't pay attention cause I didn't get how they worked before. I'll try when I get home tomorrow and see. Cause I think if it doesn't then the problem will have to be somewhere other than the cap by my theorising

Yeah hopefully. Can't find anything for a bike online for NZ stores and the ones from overseas are killers on the postage of a teeny cap

[FJRider]

Thought about it more and looked into how radiator caps work (as I said, I am very new to thinking about the mechanics of a vehicle) and it is a possibility that this could be stuffed. Is there anyway I can check this myself (without the special pressure equipment) or how much would a replacement one approx be?

Find a friend with the same model bike ... and borrow the radiator cap. See if it fixes the problem ... it may well do ...

[oracle]

No one I know even have a honda apart from someone who rides a 100AX, so that's not really feasible. Would this http://www.amazon.com/gp/product/B000GZZKJA/ref=ox_sc_act_title_1?ie=UTF8&m=A44XLGS3CDWAB be an appropriate replacement? As the radiator cap opening valve pressure is 108-137kPa. Obviously once I check the dimensions are the same

[FJRider]

No one I know even have a honda apart from someone who rides a 100AX, so that's not really feasible. Would this http://www.amazon.com/gp/product/B000GZZKJA/ref=ox_sc_act_title_1?ie=UTF8&m=A44XLGS3CDWAB be an appropriate replacement? As the radiator cap opening valve pressure is 108-137kPa. Obviously once I check the dimensions are the same

E.mail a few bike wreckers ... BEFORE you buy new ... should be cheaper ...

no rush ...

[oracle]

Yeah gonna ring up Action bike wreckers in Takapuna on Wednesday as they are scrapping another bike which takes the same cap. Just concerned that it may come up with the same fault

[hayd3n]

Yeah gonna ring up Action bike wreckers in Takapuna on Wednesday as they are scrapping another bike which takes the same cap. Just concerned that it may come up with the same fault

check out repco and supercheap they may have the same for a car.
afteralll its a radiator

[FJRider]

check out repco and supercheap they may have the same for a car.
afteralll its a radiator

Do you get your tyres from Beaurepairs ... after all ... they sell tyres ...

[p.dath]

Thought about it more and looked into how radiator caps work (as I said, I am very new to thinking about the mechanics of a vehicle) and it is a possibility that this could be stuffed. Is there anyway I can check this myself (without the special pressure equipment) or how much would a replacement one approx be?

You can probably get a cheap one from a wreckor. Perhaps try Action Bike Wreckors on Barry's Point Road in Takapuna.
http://www.kiwibiker.co.nz/wiki/Action_Bike_Wreckers

[Transalper]

... Can't find anything for a bike online for NZ stores and the ones from overseas are killers on the postage of a teeny cap

Did you phone the local Honda shop for a price first so you know whether you are saving or not?

If you remove you radiator cap and make sure it's clean, all the sealing surfaces are in good condition. Just guessing really.

[oracle]

You can probably get a cheap one from a wreckor. Perhaps try Action Bike Wreckors on Barry's Point Road in Takapuna.
http://www.kiwibiker.co.nz/wiki/Action_Bike_Wreckers

As said in a previous post, they are currently scrapping another Honda which takes the same cap so I am going to check there


Did you phone the local Honda shop for a price first so you know whether you are saving or not?

If you remove you radiator cap and make sure it's clean, all the sealing surfaces are in good condition. Just guessing really.

Cyclespot isn't open on Sunday so I will call during the one bit of time I am not at uni this week on Wednesday

[Transalper]

Cyclespot isn't open on Sunday so I will call during the one bit of time I am not at uni this week on Wednesday

Just shoot them an email.
Good luck aye. May not be as bad as you think.. but may be too.

[oracle]

Just shoot them an email.
Good luck aye. May not be as bad as you think.. but may be too.

They don't have an email address on their website, otherwise I would have already

[NinjaNanna]

Do you get your tyres from Beaurepairs ... after all ... they sell tyres ...

To be fair, when I needed a new thermo switch for the fan on my old ZX9 I found the part number in a catalog at supercheap, and found the part in stock at Repco.

Repco was $30 for a part that was going to cost $80 from Kawasaki.

[Transalper]

:sherlock: sorry, here it is....
Cyclespot/home/contact/parts... here (http://www.cyclespot.co.nz/index.php?option=com_contact&view=contact&id=2%3Aparts&catid=12%3Acontacts&Itemid=97)

parts1@cyclespot.co.nz

[hayd3n]

Do you get your tyres from Beaurepairs ... after all ... they sell tyres ...

no but most car tyre places can get motorcycle tyres in and they can also fit/ balance them
repco/supercheap stock most screw on type oil filters fore motorcycles they also stock motorcycle oil / chain lube, and ive seen aftermarket indicators/ tail lights and some headlight lenses for sale at supercheap

[Winston001]

Hang on guys, aren't we getting a bit ahead of ourselves? The radiator cap is only a guess and you'd be much better to check other aspects such as the hoses before buying a cap.

In my experience modern radiator caps rarely fail. Not much to go wrong.

Its more likely to be a tiny air leak, possibly at a connection point.

Apart from that, I agree that Supercheap etc is a perfectly good place to source stuff.

[oracle]

:sherlock: sorry, here it is....
Cyclespot/home/contact/parts... here (http://www.cyclespot.co.nz/index.php?option=com_contact&view=contact&id=2%3Aparts&catid=12%3Acontacts&Itemid=97)

parts1@cyclespot.co.nz

My apologies, I didn't realise you could click on the different categories


Hang on guys, aren't we getting a bit ahead of ourselves? The radiator cap is only a guess and you'd be much better to check other aspects such as the hoses before buying a cap.

In my experience modern radiator caps rarely fail. Not much to go wrong.

Its more likely to be a tiny air leak, possibly at a connection point.

Apart from that, I agree that Supercheap etc is a perfectly good place to source stuff.

Yes that is true but I am currently preparing for the final exams of my degree and don't think I am really confident enough to start pulling big parts of my bike off by myself (which is required to get to the hose between the radiator and overflow) so if I can get a replacement cap for say $20-$30 I would take that as a first alternative

[Haggis2]

Genuine Honda (car) radiator cap is $20.41 through Honda and appears to be identical. I'll take one home tonight and check against my VTR and let you know. Would be a cheap thing to try for a start :yes:

[Haggis2]

:shit: Sorry just clicked you're talkin 250 when I've got thou. Did a little research and they are different. Does sound like possibly a cap issue, loses coolant around there so the resevoir level doesn't change because no pressure to allow push/suck coolant to the overflow. Or as said before possible blockage of the resevoir hose, although this would be pretty unusual. Maybe more likely it has been kinked than blocked. I'd be inclined to try a cap first to see if that fixes it. Would definitely rec a new one rather than used though as who knows how good a used one is - if you still have the same problem do you know the cap is OK or just as faulty as the old one maybe? Depends on the price of course though.

Sorry couldn't be more help - good luck :bye:

[oracle]

:shit: Sorry just clicked you're talkin 250 when I've got thou. Did a little research and they are different. Does sound like possibly a cap issue, loses coolant around there so the resevoir level doesn't change because no pressure to allow push/suck coolant to the overflow. Or as said before possible blockage of the resevoir hose, although this would be pretty unusual. Maybe more likely it has been kinked than blocked. I'd be inclined to try a cap first to see if that fixes it. Would definitely rec a new one rather than used though as who knows how good a used one is - if you still have the same problem do you know the cap is OK or just as faulty as the old one maybe? Depends on the price of course though.

Sorry couldn't be more help - good luck :bye:

thanks for the suggestion anyway. From my research it is the same cap as the cbr600rr but I'm unsure what other models

[oracle]

Finally managed to get a new radiator cap and it hasn't fixed the problem. :bye: $50 wasted
So now, next step is to replace the overflow hose. Sigh, the manual calls for removing one of the carbs

[Coolz]

Could be to much air in the system, have you tried bleeding it. Should be a bolt or something for this. I know on my bike you have to bleed the system when changing the fluid, maybe this wasn't done. Just guessing here, I'm no expert.

[oracle]

Could be to much air in the system, have you tried bleeding it. Should be a bolt or something for this. I know on my bike you have to bleed the system when changing the fluid, maybe this wasn't done. Just guessing here, I'm no expert.

Will have to look into that. I have heard of "burping" the system, but never bleeding in terms of the cooling system. I still think air is getting in somehow or that there is some debris moving about and blocking the hose though cause it doesn't really have any of the symptoms of too much air in the system. At least it is one thing I can try again though. Thanks

[FROSTY]

probably this question has been asked--but you aren't filling the overflow up to the top are you?

[oracle]

probably this question has been asked--but you aren't filling the overflow up to the top are you?

Nah, I am not touching the overflow. I am filling it straight at the radiator cap because when I check there is no coolant visible there

[FROSTY]

Are you ensuring the overflow is full to at least the low level line and are you burping the system? (getting the air out of the system

[oracle]

Are you ensuring the overflow is full to at least the low level line and are you burping the system? (getting the air out of the system

Yeah the overflow is very full to the point that coolant gets pushed out of the overflow reservoir and pushed out the back through the hose. I have only just learned about burping so will try it

[oracle]

OK mate, calm down I'm fairly new to motorcycling and very new to any sort of mechanical stuff and just trying to understand, hence asking for HELP

Not burping can't have been the whole issue though as surely the mechanics I took it to would have known to burp it when they put the coolant in

[Coolz]

Worst case scenario would be a blown head gasket.

[ducatilover]

I'd try bleeding the system.
Make sure the radiator fins are clean and airflow isn't restricted.
Hardwire the fan (put a wire from the fan switch plug to earth) and ride it.
Change the thermostat, or remove it and ride.
Check the water pump impeller is okay and the bearings.
Then I'd pull the plugs out and check if it's running too lean.
If it's not too lean, check for blockages in the exhaust.
Valve clearances.


How hot is it getting on the gauge?

[oracle]

I'd try bleeding the system.
Make sure the radiator fins are clean and airflow isn't restricted.
Hardwire the fan (put a wire from the fan switch plug to earth) and ride it.
Change the thermostat, or remove it and ride.
Check the water pump impeller is okay and the bearings.
Then I'd pull the plugs out and check if it's running too lean.
If it's not too lean, check for blockages in the exhaust.
Valve clearances.


How hot is it getting on the gauge?

Woah there, as much as I am sure that all of that is a good idea it is well above my head. Highest it gets on the temperature gauge is about half way first ride after filling with coolant but can get up to just below hot if it is a long ride a few rides after I had refilled the coolant and the amount coming out from the overflow is minimal, never reaches the red.

[ducatilover]

Woah there, as much as I am sure that all of that is a good idea it is well above my head. Highest it gets on the temperature gauge is about half way first ride after filling with coolant but can get up to just below hot if it is a long ride a few rides after I had refilled the coolant and the amount coming out from the overflow is minimal, never reaches the red.
Anything above half is high on one of those, they usually read a bit low.
If it's getting too hot it won't want to drop to idle, or idle at 13-500rpm by itself.
I used to have my VT250 Spada set to 1000rpm idle (sounded cool with the exhaust I had :facepalm: and when the fan switch died, it wouldn't idle properly when it got too hot.

I'd first try hard wiring your fan and riding it like that. :sunny:

[actungbaby]

Anything above half is high on one of those, they usually read a bit low.
If it's getting too hot it won't want to drop to idle, or idle at 13-500rpm by itself.
I used to have my VT250 Spada set to 1000rpm idle (sounded cool with the exhaust I had :facepalm: and when the fan switch died, it wouldn't idle properly when it got too hot.

I'd first try hard wiring your fan and riding it like that. :sunny:

man thats good idel speed there dude 4 cylinder is like 1,200 rpm idle 1000 like car idle
shows it was runing sweet as a nut maybe that vtwin torque

whats the bros idle at

[ducatilover]

man thats good idel speed there dude 4 cylinder is like 1,200 rpm idle 1000 like car idle
shows it was runing sweet as a nut maybe that vtwin torque

whats the bros idle at
The biggest factor to get it that low was the stator output, if it was left idleing too long you'd drain the battery... sounded hot though.
My Bros650 was around 1000-1200, but it had a cam kit in it supposedly.
My 600 will sit on 900-1000 happy as Larry.

[FJRider]

Woah there, as much as I am sure that all of that is a good idea it is well above my head. Highest it gets on the temperature gauge is about half way first ride after filling with coolant but can get up to just below hot if it is a long ride a few rides after I had refilled the coolant and the amount coming out from the overflow is minimal, never reaches the red.

If the flow out the overflow is constant (even a trickle) ... it sounds like a head gasket issue. Minor thing now ... but it could get serious ... FAST.

Not all head gasket issues and symptoms are identical. Be wary of the "Mine didn't do that so thats not the problem" comments.

A compression test on all clyinders may show a drop in pressure in one (or more) cylinder(s).
As may a pressure check on the cooling system.

I would suggest you get it sorted soon ... before Murphys Law sorts it for you ... that fella murphy is a real bastard.

[oracle]

If the flow out the overflow is constant (even a trickle) ... it sounds like a head gasket issue. Minor thing now ... but it could get serious ... FAST.

Not all head gasket issues and symptoms are identical. Be wary of the "Mine didn't do that so thats not the problem" comments.

A compression test on all clyinders may show a drop in pressure in one (or more) cylinder(s).
As may a pressure check on the cooling system.

I would suggest you get it sorted soon ... before Murphys Law sorts it for you ... that fella murphy is a real bastard.

I will take a closer look at this, but would a buggered head gasket stop the coolant from being drawn back into the radiator on cooling and produce negative pressure in the radiator after a few rides?

[FJRider]

I will take a closer look at this, but would a buggered head gasket stop the coolant from being drawn back into the radiator on cooling and produce negative pressure in the radiator after a few rides?

Look up the TOTAL amount of water/coolant in the system. Check out how much the reservoir holds (from the low mark) to fill it. It may be pushing out more water than can be stored. Plus ... if the gasket IS leaking, it will NOT hold pressure ... therefore cannot "suck" it back in.

Small pressure from the cylinders may be pushing the water out ... A minor flaw in the gasket at manufacture can do it. Small multi-cylinder engines have very intricate gaskets (not to mention expensive)

If you are unsure WHAT could happen to YOUR engine ... Google Hydrauliced engines

A link ... http://answers.yahoo.com/question/index?qid=20080731235636AA3xl78

The basic theory ... air compresses ... water does not. Induction strokes suck in air/fuel. A leaking gasket can suck in WATER too. Usually not a FULL cylinder full just enoughto STOP the piston from reaching TDC.

Then ... the fire goes out ... and all noise (apart from the screeching back tyre) ... STOPS. With little warning ...

[oracle]

Look up the TOTAL amount of water/coolant in the system. Check out how much the reservoir holds (from the low mark) to fill it. It may be pushing out more water than can be stored. Plus ... if the gasket IS leaking, it will NOT hold pressure ... therefore cannot "suck" it back in.

Small pressure from the cylinders may be pushing the water out ... A minor flaw in the gasket at manufacture can do it. Small multi-cylinder engines have very intricate gaskets (not to mention expensive)

If you are unsure WHAT could happen to YOUR engine ... Google Hydrauliced engines

A link ... http://answers.yahoo.com/question/index?qid=20080731235636AA3xl78

The basic theory ... air compresses ... water does not. Induction strokes suck in air/fuel. A leaking gasket can suck in WATER too. Usually not a FULL cylinder full just enoughto STOP the piston from reaching TDC.

Then ... the fire goes out ... and all noise (apart from the screeching back tyre) ... STOPS. With little warning ...

Right, that all makes sense (sorry I am not an idiot, just very new to anything to do with mechanics). Is a compression test a relatively quick procedure that would not cost too much at the mechanics? (still a student so not a lot of spare money)

[FJRider]

Right, that all makes sense (sorry I am not an idiot, just very new to anything to do with mechanics). Is a compression test a relatively quick procedure that would not cost too much at the mechanics? (still a student so not a lot of spare money)

Both tests just take a few minutes.

Plugs out ... tester shoved in the (plug) hole ... turn the motor over a few times (on EACH cylinder) ... done.

The coolant test involves pumping water into the system to bring it just below max pressure ... watch the pressure gauge ... if it drops, find out WHERE it's going ... Takes slightly longer ...

In search of workshop work ... some places check for free. NOT ALWAYS THOUGH.

ASK ... FIRST !!!

[FJRider]

Right, that all makes sense (sorry I am not an idiot, just very new to anything to do with mechanics)

ONE thing you can do ... is check your oil. If the gasket is leaking ... it may leak into the OIL channels (which circulates the oil to the top and around the engine) This mixture turns the oil milky white.

[oracle]

ONE thing you can do ... is check your oil. If the gasket is leaking ... it may leak into the OIL channels (which circulates the oil to the top and around the engine) This mixture turns the oil milky white.

That one I have done (googling tells some info) and there is no sign of cloudiness but I understand that doesn't rule anything eitherway

[FJRider]

That one I have done (googling tells some info) and there is no sign of cloudiness but I understand that doesn't rule anything eitherway

Good to hear that. No it doesn't. But keep checking anyway.

[ducatilover]

but would a buggered head gasket stop the coolant from being drawn back into the radiator
Yes. The combustion pushes the air out, when the engine is off, you have no pressure or vacuum from the cylinder/gasket leak, so no vacuum in the cooling system to pull water back in.

If it is a headgasket, pray it's the front one, pulling the rear head off involves splitting the crank case as there is a bolt under the rear head/above the gear set inside the upper crank case :facepalm: don't ask how I know.

It's not common for these to do head gaskets though. I'd have it checked by a competent mechanic and have the cooling system pressure checked and checked for combustion gasses too.

Good luck :D