Water Temperature Sender Unit Removal

The rev counter I've bought has a sender unit to display the water temperature.  It's a case of removing the existing sender unit from the rad & replacing it with the one supplied.  Has anyone ever removed the rad temperature switch ?  Is it a rad out job or is there enough wiggle room there?

I never removed mine but it looked tight for working space in there   does the new one replace the "Red" Overheat light?

Not had a good look yet Sim - I think it gives you an actual temperature in figures - according to the manual, the switch is on at 120 c, so as long as it stays below that, I'm assuming it's fine (famous last words)

You'll get a more accurate reading if you fit the sender to the by-pass hose at the bottom of the frame on the left side Dave, probably easier to fit there too? if you fit it to the sender at the top of the rad? the water has cooled as it's passed through the rad giving a lower reading, it's not much for an inline sender boss for the by-pass tube, could be worth reading this Link to give possible idea's?

I may be wrong on this Sim, but I thought that the temperature sender gauge (for the warning light), is part number 13 on this diagram, which is located at the top of the rad.




I would have thought that if it was giving a reading for the warning light, it would give an accurate reading for a digital gauge.  The sender is a direct replacement for the existing sender (supposedly), so should be easier to fit directly into the rad, rather than chopping into the pipework.  You can get an adapter to fit into the hose, but it cost £25.00.  If I can get this one in, I'll give it a go.

I agree Dave, it is the one at the top of the rad,  but the flow of the coolant is clockwise (looking from the left side of the bike) meaning that the coolant has passed through the engine and pump before going through the rad (being cooled) before reaching that sensor, to give an accurate reading of engine coolant temp surely it should come from the first point of engine exit?, No chopping of the pipes is needed as there's a plastic OEM connector in that position already, it's just a matter of crimping the pipe temporarily to fit the boss, and then releasing the right hand one with no sender in the valve to allow the coolant to flow through before crimping it back again before fitting the sensor as to not create an air lock, I'll be interested to see the readings from the top rad position if you go that route though? it's only a small cooling system, it'll be good to see if there's any the number variations 

Not found that connector yet Sim.  I'm still working on the basis that if the position of the original sender is good enough for Mr Suzuki, it'll be good enough for me - I'm not looking for spot-on accuracy, just an indication of what's happening.  Mind you, if it's a pain in the arse to fit, I'll just leave the original sender in place.  I'm not one for making unnecessary work for myself

Dave, what ever way you go is better that the OEM "Red" Overheat light they only come on at 120c (stop now) running temp is 80-90°C
its the same with oil pressure sensor (OEM) they only come on at the (stop now) its to low, there your last line of defense

Never having had a water-cooled bike before (last bike was an '83 Katana 1100), I'd never considered what the coolant was running at, but as the rev counter had the option for measuring the temperature, I thought it'd be worth it.  I've fitted an oil temperature gauge as well (one of the screw-in jobbies that replaces the standard filler cap.

katsd wrote:

Never having had a water-cooled bike before (last bike was an '83 Katana 1100), I'd never considered what the coolant was running at, but as the rev counter had the option for measuring the temperature, I thought it'd be worth it.  I've fitted an oil temperature gauge as well (one of the screw-in jobbies that replaces the standard filler cap.

You'll spend more time watching the numbers and worrying if everything's alright                 

Yeh - sometimes ignorance is bliss (I've been ignorant all my life & I'm pretty blissful)

Have you fitted and had the rev counter working yet Dave ? Just wondered how stable the needles was.
Having done a little research, the only type of Rev counter which will read accurately will be one driven by a "stepper motor". A stepper motor is a positively driven motor therefore there is little or no play in the needle movement. The stronger the stepper motor, the more stable the reading. These types of gauge are expensive ( cheapest I've seen suitable for a bike is £99.00 from Koso Gauges ) but the needles are steady and reliable.
Not sure if the Daytona one you have has this feature Dave ..... if so it should be OK

No Mick - not yet. At the moment I still have all the stuff at the powder coaters - including the bracket I've had fabricated for the tacho. I was supposed to phone then a couple of days ago, but I've that many other things on the go at the moment, I just forgot. I need to fit the auxiliary fuse box before I can fit the tacho, but before I do that, I want to tidy the wiring in the headlight bucket. The way things are going at the moment, I can see this dragging on till May !!!

At the end of the day, I have an email from the suppliers stating that they have had no problems with the Daytona - if this is not correct, it goes back.

Twojobmick wrote:The signal cable is connected directly to the + side of the coil Dave. I put a piggy back spade terminal on to the tacho signal cable, then connected the LT coil connection on to that .

I'm sure it'll be obvious once I lift the tank Mick but so I'm not spending ages chasing up the wrong tree can you point me in the right direction please?  Which is the LT coil connection?  The wiring diagram shows two coils (as you previously pointed out to me we have two coils!!!), a front & rear.  It looks like each coil has (apart from the earth lead) two feeds out - one to the ignitor, & one to the starter/kill switch on the bars.  I would have gone for the front coil feed to the ignitor - am I miles out there ?

Why did you go for the coils rather than the plug lead?  Cheers

Dave, I went for connection to the coil as the rev counter I bought didn't have an option to wrap a cable around the HT lead as your has.
The way I saw it was this : the coil had three connections on it. One was the HT lead out to the plug, an obvious non starter for connection, then there's the LT side ...... with a + terminal and a - terminal on it. I simply put a piggy back spade terminal on to my signal wire, then attached that to the + terminal, then attached the + cable from the ECU on to the piggy back .... Simple as that ! The - connection for the gauge was picked up from a multiple connection I made from the spare switched supply in the headlight bucket. You need to bear in mind though that I have multiple gauges in my dash panel which is why I did it this way. You can pick a - up from wherever is convenient on your setup.
The gauge read correctly, it was just that the needle was really finely balanced which caused it to swing about wildly whilst the bike was moving and that damaged the internal mechanism of the gauge.
I would think all you really need is a switched + and - from the headlight connector, a signal cable, either coil connected or wrapped around the HT lead and a supply from the lighting circuit ( I spliced in to the sidelight inside the headlight bucket ) for the backlight. Some gauges don't even need a - for the backlight, they use the supply - for this, it all being connected internally. Dont worry about where the wiring from the coils goes to, you are only tapping off it for a signal ( if you go that way for your signal connection ). Just check with the instructions though - some rev counters connect to the negative side of the coil for signal.
Hope this helps mate ...... I can't post any pictures to help without stripping the bike down but I think it's fairly self explanatory. One tip - don't overanalyse it ..... It'll drive you crazy ! Just do it !

Thanks for that Mick - your's is an FI model then - sorry, I thought yours was carbed !!!!  Soon as I get round to lifting the tank, it'll be obvious.  Wiring the power in should be a doddle now I've fitted the auxiliary fuse box - fitting the tacho was what made me decide to fit the box.

Thanks for the pointers - I'll give you an update when it's finished

katsd wrote:

Thanks for that Mick - your's is an FI model then - sorry, I thought yours was carbed !!!!  

Mick's is Carbed Dave, I think he was referring to connecting the Tacho to the piggy back connector, not the ECU 

simbo wrote:

katsd wrote:

Thanks for that Mick - your's is an FI model then - sorry, I thought yours was carbed !!!!  

Mick's is Carbed Dave, I think he was referring to connecting the Tacho to the piggy back connector, not the ECU 

Yeah sorry Dave, Sim is right .

Mick - fitted today 

That looks good Dave, expensive???

£85 + £10 for the optional temperature sender.  Expensive compared to some (but cheaper than a Baron) - but I'd rather pay the extra & have a decent unit