Post by Jaz66 on Dec 24, 2008 14:05:01 GMT 1
Hi here are a collection of post by NTV Members with informative tips about - [post amended 28/11/08]
The Radiator Fan on the Honda NTV
Please see growell.proboards49.com/index.cgi?board=tech&action=display&thread=574for a guide on how to use.
Please keep post ON topic...
____________________________________________________
The RADIATOR FAN:
What NTV Owners say you CAN expect the fan to do Normally:
* I've had my fan come on on really hot days in traffic. It comes on when the temp Gauge is about 2/3 the way up. The sensor usually triggers just above 90 degrees 'C'.
**************************
* I have the NTV 650 and riding through traffic (London) will see the needle go up to the middle of the dial. My fan though has never cut in, but we have not had a hot summer this year.
**************************
* The fan shouldn't normally be needed in normal riding, especially in the cold weather, unless you're stationary in heavy traffic for a long time. My 160 mile daily commute only sees the needle creep up into the bottom of the 'normal' section of the Gauge.
**************************
* The fan should kick in at 93-97C on the temp gauge, this is quite high on the band, say approx 80% of the way to the red line.
**************************
* The sensor is in the radiator, left hand side and earths the fan switch when it gets hot enough. Unless you were riding slowly in traffic on a very hot day, you won't see the fan come on that much.
___________________________________________________
What to do if you suspect problem with your fan.
SIMPLE TESTS
* One thing worth checking is that your radiator fins are not blocked. The radiator picks up a lot of muck from the front wheel. The center section of my 25,000 mile 1998 bike was blocked with dirt when I bought the bike. I cleaned it out with a soft probe and compressed air. It is worth putting a rag behind it as otherwise all the dirt blows over the engine.
**************************
* At various speeds stop and feel the bottom hose from the radiator. It should be significantly cooler than the top one. This is the effect of air passing through The radiator cooling the water inside. If at increased power levels the bottom hose starts to get near the same temp as the top one the radiator is not functioning as it should and the temp will start to climb. If you slow down and use less power and the temp begins to return to normal it is likely the radiator is blocked either externally or internally.
**************************
____________________________________________________
More technical testing
* It's probably an idea to short out the lead to the temperature sensor on the radiator against the frame to make sure the fan is OK- mine wouldn't work once because a piece of crud had found its way between the blades and the shroud (and it took some delicate ferkling to get it out )
**************************
* My rad fan isn't working. I've bridged out the rad temp switch and it does work fine so I replaced the switch. still doesn't come on. Took fan off cleaned earth connection as it was rather covered in crap. Its got to be something in the wiring if cleaning the earth connection up doesn't work.
**************************
* With the ignition on, I suggest that you test that power is getting to the sensor (multimeter or a bulb). If not, it's your wiring or fuses. If you get power, check that the wire from the sensor to the fan is continuous. If that wire is OK it looks like the sensor is kaput.
**************************
* I fixed my fan a couple a months ago. Checked the fan it self by connecting a battery. The fan didn't come on. Took it apart and examined and it turned out that there were no contact between fan rotor and contact pins (located in plastic unit, you can take it apart with some mild force) a lot of WD40 and the pins eventually came out. Voila, saved me some money.
Now the fan comes on at about 2/3 of white marking.
Hope it will help.
**************************
First we have to assume the temp gauge is not working because the water is not hot. To test the dash end of the gauge remove the wire from the sender unit on top of engine, switch on the ign. The gauge should not rise. Earth the wire to the engine and the gauger should rise to the top within a few seconds. If this is the case its a fair indication the sender unit on the top of the engine is wrong/faulty so replace it. If the gauge doesn't rise there is a problem either in the wiring or the gauge itself. This in itself wont make the system overheat, it just fails to show you it is overheating.
If the fan is obviously not working. Switch on the ignition. Remove the wire from the switch on the end of the radiator and earth it to the engine. The cooling fan should run. If it does then earth it to the metal of the radiator. If the fan runs at this stage the radiator is earthed and the fault is likely to be in the switch. This is a common fault. If it doesn't run but has ran when earthed to the engine then you have a fault with the little wire which earths the radiator to the frame. If it doesn't run in any of the above the fan or wiring is at fault and is most likely to be brushes stuck/corroded inside the fan. Not an easy fix.
**************************
* The temp Gauge sender is in the thermostat housing, where you top up coolant.
Make sure it's connected of course, it's likely to be a single, torpedo connection straight onto the sensor. If your coolant level is low, the temp sender doesn't seem to get hot and might indicate a cool engine. Weird as I would have expected the steam to do the trick anyway. More importantly, if your coolant is very low, the fan switch in the radiator doesn't get hot enough to activate the fan either. I set up a permanent, switched earth before realising the coolant problem.
___________________________________________________
OVERVIEW OF RADIATOR & FAN Plus In Depth technical help
Overview
* The thermostat only controls the flow of water around the engine and through the radiator. The 'stat is normally closed when cold, the water pump is permanently pumping, attached to the rear of the oil pump, which is in turn driven by a chain from the clutch end of the crankshaft.
Water is pumped around the engine and bypasses the radiator, until the 'stat warms up and opens (at circa 80-84C, and is fully open at 95C), this then permits the hot water to circulate through the radiator, entering from the top (right hand side) and exiting from the bottom (left hand side), where it goes back through the pump, then the engine.
Having no thermostat simply means the water will circulate through the radiator all of the time. The bike will take longer to warm up and likely run cooler, especially at this time of the year.
It's a closed pressurised system; when the water heats up, it expands. The Pressure cap will open at 13 - 18psi and allow excess pressure to escape into the header tank (white plastic immediately behind the engine). Header tank can be topped up from behind the left hand side panel. The header tank is part of the closed system, when the engine is switched off and cools back down, pressure in the cooling system drops and sucks coolant back in from the header tank. The pressure cap has a central "valve" which opens inwards to allow this.
If the header tank overfills, it overflows from another pipe (in a group of 3) just near the centre stand. Overflowing header tanks are likely to be a result of overfilling (in which case it happens once only), poor seal or excessive pressure in the system. Excessive pressure is likely to be caused by leaking head gasket (which I think is my problem), allowing pressure from the cylinders into the cooling system.
____________________________________________________
More In depth tips
* have you checked the o ring that fits between the thermostat housing and the rad cap housing, under the air filter bottom casing. I have had to replace mine recently as they go rock hard and cannot seal up when thermal expansion occurs.
**************************
* I was loosing small amounts of coolant and it was running really warm at times, so gave the bike a service while at a mates place, ( warm workshop, and a bike lift up to head height) and with the tank off while it was still warm, checked the hoses for cracks etc and found that the o ring was leaking by when at full running temp, but not when cool.
**************************
* Radiator fan switch? We all know in this case the geniune one is too expensive so here's an alternative. Go to a motor factor, auto electro outlet/repairer who stocks LUCAS electrical equipment and get yourself Lucas number SNJ100. Its from a NISSAN something, if anyone needs to know what model I can go and check. This switch comes on at around 90 so is a little lower than the original but that will do no harm as a matter of fact probably better. It also comes with two wires instead of one, so just earth one and put the other to the original switch connection. This switch is for switching on a larger output fan than the tinsey wee things on a bike so is more than up to the job.
I however have mine wired through a relay as fan switch's even on cars give trouble unless originally powered via relays. Maybe some will think thats a bit overkill but it works and keeps working.
I also had the problem of the brush's sticking inside than fan, so dismantled the thing and freed them up.
Another thing while we are on cooling/heating is that some of these bikes run too cool most of the time. Check the thermostat hasn't fallen apart allowing free flowing of the coolant even when cold as this running at cool and varying temps does no good to an engine nor economy.
A replacement stat from a breakers should be able to be got for a few ££s if not and you don't like the cost of new here's a real cheap skate one for you all. Go to an aftermarket supplier of Landrover parts and get a thermostat for a 2.5ltr Landrover 90/110 circa 84 for buttons. This will need a bit of a trim but be careful and it will fit without fouling either top nor bottom. This is a bit heath Robinson or maybe a miserable g--- type of a job but it works and it done me for a few years and kept my engine from running like an ice box in colder weather.
**************************
* There is a kit available to test for combustion gases entering the cooling system. It consists of a bottle thingy with a valve in the bottom. You fill it up to a mark on side with the supplied chemical. Start the engine, let it run for a couple of Min's then give it a rev or two. If there is bubbles comes up through the liquid and the liquid changes colour it shows there is combustion gases entering the cooling system usually from a head gasket problem or worse a crack possibly in either of the cyl heads.
You probably wont have this equipment available so fill it with water when cool. Leave the rad cap off. Start it and shortly after rev it up a few times. Good full throttle openings but dint let it rev it up too high, theres no need. The water will probably move up and down and maybe run over the filler but should not blow out nor have any bubbles. If no bubbles and the water is not rushing out fix all the other problems with the fan etc and give it a run.
If there is a problem with gasses/pressure entering the cooling system get two extra spark plugs. Remove the plug leads from one cyl and put the extra plugs on the leads. Make sure the threaded part of the plug is laying against the engine to earth them. The engine will now start on one cyl. It wont tickover, thats OK just keep it going with the throttle. By stopping it firring on any given cyl the problem cyl will no longer produce gases and the gases will no longer enter the cooling system. You should then know which cyl needs something done with it. Usually a head gasket. Usually caused by the fan not working or a coolant leak in the past resulting in the engine overheating. Dint run the engine with the plug leads disconnected and no plugs on the ends and them earthed. There is a consensus that has a fairly sound theory about back feeds which sooner or later will destroy the ign/cdi unit.
The switch is a usual problem but is quite expensive.
There is a alternative from a Nissan something but I cant remember. It is mentioned including the Lucas part number by me in a thread some time back.
I hope this helps you. I am a firm believer that if it ain't broke dint fix it. So if it only needs one gasket thats what it should get. The guys who get the big miles from machines take care of them but dint pamper them.
_________________________________________________-
FAN MOTOR: strip and repair
The fan motor is pretty easy to strip, but it may have gone fatal. It's worth trying some penetrating spray and leaving the assembly on its side for a day or two with repeated squirts to assist it getting in there (then turn it over and try the other side. I would try this to get the armature turning before trying to disassemble.
Take the fan off the spindle (be careful, with age and use, the blades get brittle and will easily snap off. The fan is on a tapered fit to the spindle) and you get access to three philips screws. remove those and the motor backing plate will be stuck with sealant to the body of the fan assembly. Carefully lever this off (could be awkward if there is no movement of the armature). The brushes are on springs inside this housing. If I recall correctly, it is possible to replace them but you may end up having to adapt something from eg washing machine.
You can now grasp the armature and try to move and remove it. The armature bearings are plain bushes. I'm guessing if it is still resisting your efforts it's a goner - even if you get it out and clean everything up, it isn't going to last long, but hopefully enough to allow you to source a replacement.
I understand that WD40 is not too wonderful for use on electrical motors, it leaves a residue, so when you're inside the casing, using an electrical contact spray for cleaning etc.
Reassembly is straightforward reversal of the above, clean the surfaces and apply some silicon sealant to the joint.
-------------------------------------------------------------------------------
IF unable to Fix, What do you do next?
John w writes
Watch out for the cooling fan failing. Cant repair, must replace, but other of other Hondas fit, I replace mine with one of a VFR, just changed the frame it come with. Try any bike breaker when you need one, and you will usually find one that fits.
___________________________________________________
This post was made possible due to the contributions of the following NTV members;
derbyshirebill, ntvnick, danny, rusty, and particular mention for Honda and McF
____________________________________________________
Please feel free to contribute / rectify / add to this post.
Alternatively why not create your own FACT FILE?
Why not use the 'Template' from the start of this post
and simply change the topic?
NTV FACT FILE FORUM
The Radiator Fan on the Honda NTV
Please see growell.proboards49.com/index.cgi?board=tech&action=display&thread=574for a guide on how to use.
Please keep post ON topic...
____________________________________________________
The RADIATOR FAN:
What NTV Owners say you CAN expect the fan to do Normally:
* I've had my fan come on on really hot days in traffic. It comes on when the temp Gauge is about 2/3 the way up. The sensor usually triggers just above 90 degrees 'C'.
**************************
* I have the NTV 650 and riding through traffic (London) will see the needle go up to the middle of the dial. My fan though has never cut in, but we have not had a hot summer this year.
**************************
* The fan shouldn't normally be needed in normal riding, especially in the cold weather, unless you're stationary in heavy traffic for a long time. My 160 mile daily commute only sees the needle creep up into the bottom of the 'normal' section of the Gauge.
**************************
* The fan should kick in at 93-97C on the temp gauge, this is quite high on the band, say approx 80% of the way to the red line.
**************************
* The sensor is in the radiator, left hand side and earths the fan switch when it gets hot enough. Unless you were riding slowly in traffic on a very hot day, you won't see the fan come on that much.
___________________________________________________
What to do if you suspect problem with your fan.
SIMPLE TESTS
* One thing worth checking is that your radiator fins are not blocked. The radiator picks up a lot of muck from the front wheel. The center section of my 25,000 mile 1998 bike was blocked with dirt when I bought the bike. I cleaned it out with a soft probe and compressed air. It is worth putting a rag behind it as otherwise all the dirt blows over the engine.
**************************
* At various speeds stop and feel the bottom hose from the radiator. It should be significantly cooler than the top one. This is the effect of air passing through The radiator cooling the water inside. If at increased power levels the bottom hose starts to get near the same temp as the top one the radiator is not functioning as it should and the temp will start to climb. If you slow down and use less power and the temp begins to return to normal it is likely the radiator is blocked either externally or internally.
**************************
____________________________________________________
More technical testing
* It's probably an idea to short out the lead to the temperature sensor on the radiator against the frame to make sure the fan is OK- mine wouldn't work once because a piece of crud had found its way between the blades and the shroud (and it took some delicate ferkling to get it out )
**************************
* My rad fan isn't working. I've bridged out the rad temp switch and it does work fine so I replaced the switch. still doesn't come on. Took fan off cleaned earth connection as it was rather covered in crap. Its got to be something in the wiring if cleaning the earth connection up doesn't work.
**************************
* With the ignition on, I suggest that you test that power is getting to the sensor (multimeter or a bulb). If not, it's your wiring or fuses. If you get power, check that the wire from the sensor to the fan is continuous. If that wire is OK it looks like the sensor is kaput.
**************************
* I fixed my fan a couple a months ago. Checked the fan it self by connecting a battery. The fan didn't come on. Took it apart and examined and it turned out that there were no contact between fan rotor and contact pins (located in plastic unit, you can take it apart with some mild force) a lot of WD40 and the pins eventually came out. Voila, saved me some money.
Now the fan comes on at about 2/3 of white marking.
Hope it will help.
**************************
First we have to assume the temp gauge is not working because the water is not hot. To test the dash end of the gauge remove the wire from the sender unit on top of engine, switch on the ign. The gauge should not rise. Earth the wire to the engine and the gauger should rise to the top within a few seconds. If this is the case its a fair indication the sender unit on the top of the engine is wrong/faulty so replace it. If the gauge doesn't rise there is a problem either in the wiring or the gauge itself. This in itself wont make the system overheat, it just fails to show you it is overheating.
If the fan is obviously not working. Switch on the ignition. Remove the wire from the switch on the end of the radiator and earth it to the engine. The cooling fan should run. If it does then earth it to the metal of the radiator. If the fan runs at this stage the radiator is earthed and the fault is likely to be in the switch. This is a common fault. If it doesn't run but has ran when earthed to the engine then you have a fault with the little wire which earths the radiator to the frame. If it doesn't run in any of the above the fan or wiring is at fault and is most likely to be brushes stuck/corroded inside the fan. Not an easy fix.
**************************
* The temp Gauge sender is in the thermostat housing, where you top up coolant.
Make sure it's connected of course, it's likely to be a single, torpedo connection straight onto the sensor. If your coolant level is low, the temp sender doesn't seem to get hot and might indicate a cool engine. Weird as I would have expected the steam to do the trick anyway. More importantly, if your coolant is very low, the fan switch in the radiator doesn't get hot enough to activate the fan either. I set up a permanent, switched earth before realising the coolant problem.
___________________________________________________
OVERVIEW OF RADIATOR & FAN Plus In Depth technical help
Overview
* The thermostat only controls the flow of water around the engine and through the radiator. The 'stat is normally closed when cold, the water pump is permanently pumping, attached to the rear of the oil pump, which is in turn driven by a chain from the clutch end of the crankshaft.
Water is pumped around the engine and bypasses the radiator, until the 'stat warms up and opens (at circa 80-84C, and is fully open at 95C), this then permits the hot water to circulate through the radiator, entering from the top (right hand side) and exiting from the bottom (left hand side), where it goes back through the pump, then the engine.
Having no thermostat simply means the water will circulate through the radiator all of the time. The bike will take longer to warm up and likely run cooler, especially at this time of the year.
It's a closed pressurised system; when the water heats up, it expands. The Pressure cap will open at 13 - 18psi and allow excess pressure to escape into the header tank (white plastic immediately behind the engine). Header tank can be topped up from behind the left hand side panel. The header tank is part of the closed system, when the engine is switched off and cools back down, pressure in the cooling system drops and sucks coolant back in from the header tank. The pressure cap has a central "valve" which opens inwards to allow this.
If the header tank overfills, it overflows from another pipe (in a group of 3) just near the centre stand. Overflowing header tanks are likely to be a result of overfilling (in which case it happens once only), poor seal or excessive pressure in the system. Excessive pressure is likely to be caused by leaking head gasket (which I think is my problem), allowing pressure from the cylinders into the cooling system.
____________________________________________________
More In depth tips
* have you checked the o ring that fits between the thermostat housing and the rad cap housing, under the air filter bottom casing. I have had to replace mine recently as they go rock hard and cannot seal up when thermal expansion occurs.
**************************
* I was loosing small amounts of coolant and it was running really warm at times, so gave the bike a service while at a mates place, ( warm workshop, and a bike lift up to head height) and with the tank off while it was still warm, checked the hoses for cracks etc and found that the o ring was leaking by when at full running temp, but not when cool.
**************************
* Radiator fan switch? We all know in this case the geniune one is too expensive so here's an alternative. Go to a motor factor, auto electro outlet/repairer who stocks LUCAS electrical equipment and get yourself Lucas number SNJ100. Its from a NISSAN something, if anyone needs to know what model I can go and check. This switch comes on at around 90 so is a little lower than the original but that will do no harm as a matter of fact probably better. It also comes with two wires instead of one, so just earth one and put the other to the original switch connection. This switch is for switching on a larger output fan than the tinsey wee things on a bike so is more than up to the job.
I however have mine wired through a relay as fan switch's even on cars give trouble unless originally powered via relays. Maybe some will think thats a bit overkill but it works and keeps working.
I also had the problem of the brush's sticking inside than fan, so dismantled the thing and freed them up.
Another thing while we are on cooling/heating is that some of these bikes run too cool most of the time. Check the thermostat hasn't fallen apart allowing free flowing of the coolant even when cold as this running at cool and varying temps does no good to an engine nor economy.
A replacement stat from a breakers should be able to be got for a few ££s if not and you don't like the cost of new here's a real cheap skate one for you all. Go to an aftermarket supplier of Landrover parts and get a thermostat for a 2.5ltr Landrover 90/110 circa 84 for buttons. This will need a bit of a trim but be careful and it will fit without fouling either top nor bottom. This is a bit heath Robinson or maybe a miserable g--- type of a job but it works and it done me for a few years and kept my engine from running like an ice box in colder weather.
**************************
* There is a kit available to test for combustion gases entering the cooling system. It consists of a bottle thingy with a valve in the bottom. You fill it up to a mark on side with the supplied chemical. Start the engine, let it run for a couple of Min's then give it a rev or two. If there is bubbles comes up through the liquid and the liquid changes colour it shows there is combustion gases entering the cooling system usually from a head gasket problem or worse a crack possibly in either of the cyl heads.
You probably wont have this equipment available so fill it with water when cool. Leave the rad cap off. Start it and shortly after rev it up a few times. Good full throttle openings but dint let it rev it up too high, theres no need. The water will probably move up and down and maybe run over the filler but should not blow out nor have any bubbles. If no bubbles and the water is not rushing out fix all the other problems with the fan etc and give it a run.
If there is a problem with gasses/pressure entering the cooling system get two extra spark plugs. Remove the plug leads from one cyl and put the extra plugs on the leads. Make sure the threaded part of the plug is laying against the engine to earth them. The engine will now start on one cyl. It wont tickover, thats OK just keep it going with the throttle. By stopping it firring on any given cyl the problem cyl will no longer produce gases and the gases will no longer enter the cooling system. You should then know which cyl needs something done with it. Usually a head gasket. Usually caused by the fan not working or a coolant leak in the past resulting in the engine overheating. Dint run the engine with the plug leads disconnected and no plugs on the ends and them earthed. There is a consensus that has a fairly sound theory about back feeds which sooner or later will destroy the ign/cdi unit.
The switch is a usual problem but is quite expensive.
There is a alternative from a Nissan something but I cant remember. It is mentioned including the Lucas part number by me in a thread some time back.
I hope this helps you. I am a firm believer that if it ain't broke dint fix it. So if it only needs one gasket thats what it should get. The guys who get the big miles from machines take care of them but dint pamper them.
_________________________________________________-
FAN MOTOR: strip and repair
The fan motor is pretty easy to strip, but it may have gone fatal. It's worth trying some penetrating spray and leaving the assembly on its side for a day or two with repeated squirts to assist it getting in there (then turn it over and try the other side. I would try this to get the armature turning before trying to disassemble.
Take the fan off the spindle (be careful, with age and use, the blades get brittle and will easily snap off. The fan is on a tapered fit to the spindle) and you get access to three philips screws. remove those and the motor backing plate will be stuck with sealant to the body of the fan assembly. Carefully lever this off (could be awkward if there is no movement of the armature). The brushes are on springs inside this housing. If I recall correctly, it is possible to replace them but you may end up having to adapt something from eg washing machine.
You can now grasp the armature and try to move and remove it. The armature bearings are plain bushes. I'm guessing if it is still resisting your efforts it's a goner - even if you get it out and clean everything up, it isn't going to last long, but hopefully enough to allow you to source a replacement.
I understand that WD40 is not too wonderful for use on electrical motors, it leaves a residue, so when you're inside the casing, using an electrical contact spray for cleaning etc.
Reassembly is straightforward reversal of the above, clean the surfaces and apply some silicon sealant to the joint.
-------------------------------------------------------------------------------
IF unable to Fix, What do you do next?
John w writes
Watch out for the cooling fan failing. Cant repair, must replace, but other of other Hondas fit, I replace mine with one of a VFR, just changed the frame it come with. Try any bike breaker when you need one, and you will usually find one that fits.
___________________________________________________
This post was made possible due to the contributions of the following NTV members;
derbyshirebill, ntvnick, danny, rusty, and particular mention for Honda and McF
____________________________________________________
Please feel free to contribute / rectify / add to this post.
Alternatively why not create your own FACT FILE?
Why not use the 'Template' from the start of this post
and simply change the topic?
NTV FACT FILE FORUM
