My European 102hp has more torque than an American 145hp?

[02GF74]

. If you have access to a CO meter you may also get a reading with the probe held over the coolant (NOT in it!).

There is a fluid that is sold which changes colour on contact with combustion gases, see below.

Easy and relatively easy to do. (not used it myself)

 

[AP76ita]

Assuming that the fluid that goes into the expansion tank returns when the engine cools down then that is normal. Indicators of a blown head gasket would be coolant being forced out of the header tank over flow pipe and, with the pressure cap off, you may see bubbles in the header manifold. If you have access to a CO meter you may also get a reading with the probe held over the coolant (NOT in it!).

I've never checked rad temperature with an IR thermometer so can't say with any certainty if the data you have collected is normal or not. I assume that they were taken when the motor was at 'operating' temperature, the readings taken one immediately after the other and the fan not running?
Perhaps someone else who doesn't have any cooling issues could do a similar exercise and report back their finding?

Your pictures show the coolant entering the top of the rad at 66°C and exiting at 50°C. What I don't understand is how the temperature rises to 74°C at the bottom LH corner, is 38°C at the middle top and 51°C RH top.
Without the fan running I would have expected the temperatures across the top to be similar and show a reasonably consistent drop as you go down the rad. That is my theory which may be a load of 'olloks and I'm happy to be corrected.

My gut feel (dangerous, I know) is that the radiator is partially blocked and it is this which is causing the issue.

Have a look here to see how to check the coolant temperature indicator operation.

Should have specified when I posted pics
Yes all pics were taken all together in few seconds
But, temperature was indicated as in picture, in red zone of vmax instrument
And fan was running

I was concerned too about radiator different temperature spots
Mechanic wanted to cut it clean and solder again, but said he let it stay in acid, then let it flow under pressure and it flew correctly. But worth inspecting it better for sure

Thanks for link for temp check but I bought the sensor and I'll install that one, ride bike until instrument goes red and then see temp shown on electronic instrument

 

[AP76ita]

Regarding your nice explanation on vmax's cooling system, then if I don't have to refill coolant it means it wasn't pushed out But recovered so should be fine right ?

 

[AP76ita]

There is a fluid that is sold which changes colour on contact with combustion gases, see below.

Easy and relatively easy to do. (not used it myself)
View attachment 80579

Thanks yes I bought it and will do the test in next days as soo as I have time
I'm working 7am - 10pm these weeks!

 

[MaxMidnight]

Regarding your nice explanation on vmax's cooling system, then if I don't have to refill coolant it means it wasn't pushed out But recovered so should be fine right ?

That is the purpose of the design. As coolant expands it needs to go somewhere and that's the job of the expansion tank.
In the 'good old days' it was necessary to check coolant levels as the displaced fluid was dumped out of the overflow. Those who checked would then fill up with water from the tap and over time the corrosion inhibitors were diluted which allowed crud to build up and get stuck it the narrow rad cores...you can work out the rest!

 

[AP76ita]

That is the purpose of the design. As coolant expands it needs to go somewhere and that's the job of the expansion tank.
In the 'good old days' it was necessary to check coolant levels as the displaced fluid was dumped out of the overflow. Those who checked would then fill up with water from the tap and over time the corrosion inhibitors were diluted which allowed crud to build up and get stuck it the narrow rad cores...you can work out the rest!

Yes mechanic said he found lot of rust in cooling circuit, that's why he feared about a head gasket failure. Feared a rust corrosion.
But in these weeks coolant stayd at level so should not have been pushed out on the road
I have to hope for instrument malfunctioning!

 

[MaxMidnight]

My money is still on the radiator.

 

[AP76ita]

My money is still on the radiator.

Where you bet I bet then
So is it a good thing take it to a radiator specialist who will cut, open, clean and solder back?

 

[02GF74]

Normally the cores are replaced.

Note that there are aftermarket alloy radiators available that supposed to have higher cooling capacity.

Someone on here bought one but found the mounting holes we misaligned and then something else got in the way to prevent fitting.

 

[AP76ita]

Normally the cores are replaced.

Note that there are aftermarket alloy radiators available that supposed to have higher cooling capacity.

Someone on here bought one but found the mounting holes we misaligned and then something else got in the way to prevent fitting.

Thanks great advise on AM
I probably would have considered given high cost of OEM new
An used one could have similar issue though
My mechanic told me the radiator specialist daily cuts, cleans and solders back no issues, but in mime they decided not to do it because after acid forced circulation they evaluated that flow was good
Before buying a new radiator I'll let them do the open/resolder job I guess

 

[MaxMidnight]

Where you bet I bet then
So is it a good thing take it to a radiator specialist who will cut, open, clean and solder back?

WARNING: Those offering advice here are doing so based on what you have posted and their experience BUT that doesn't mean they are correct!
Use their suggestions to make a diagnosis yourself before spending any money. Work through the system methodically so you know what isn't causing the issue and what's left is the problem.

If you haven't done it already, remove the heat shield and as the motor heats up use your hand to feel around the rad core.
You should start to feel it get warm evenly across the core; any colder spots will indicate a partial or full blockage.
IMO you skin is a more sensitive tool at these relatively lower temperatures.

As coolant temperature increases conduction will heat up the blocked parts of the core which may well mask the problem.

 

[02GF74]

The water used to refill may contain calcium carbonates that over time build up inside the radiator (hence why I use deionised water).

There are branded products that supposed to remove that, also vinegar (an acid) has also been suggested.

I tried both methods on a car radiator but not convinced either was particularly effective.

 

[AP76ita]

WARNING: Those offering advice here are doing so based on what you have posted and their experience BUT that doesn't mean they are correct!
Use their suggestions to make a diagnosis yourself before spending any money. Work through the system methodically so you know what isn't causing the issue and what's left is the problem.

If you haven't done it already, remove the heat shield and as the motor heats up use your hand to feel around the rad core.
You should start to feel it get warm evenly across the core; any colder spots will indicate a partial or full blockage.
IMO you skin is a more sensitive tool at these relatively lower temperatures.

As coolant temperature increases conduction will heat up the blocked parts of the core which may well mask the problem.

Thanks for advise, don't worry was just because you're giving so many suggestions so I take them on big consideration, but of course I know you're thousands miles away, never saw the bike and just basing upon what I report which may also be wrong

I'll try the hand test before heats up too, then I still have the 2nd sensor/display to install and will do the blu liquid test

 

[AP76ita]

The water used to refill may contain calcium carbonates that over time build up inside the radiator (hence why I use deionised water).

There are branded products that supposed to remove that, also vinegar (an acid) has also been suggested.

I tried both methods on a car radiator but not convinced either was particularly effective.

Got it, we're unsure about rad internal status even after acid treatment

We have to thoroughly inspect

 

[AP76ita]

Update, finally installed the temperature sensor and display
Idle, heats up, bike instrument reaches almost red, fan starts when display shows 105°C (221°F) which is the bulb spec, so fine
But temperature won't lower no matter how long I leave bike idle with fan running

So we wonder either some radiators lines not fully flowing
Or the plastic internal gear of water pump which may be broken/loose

So we'll first try quick install of another radiator to check if fan then will coll water
If not we'll check pump's internal gear

Is it correct that while idle, if I leave bike with fan running it should cool water down, and fan should stop?
Or its normal that fan keeps running with no effect on water temp?

Note that I then went for a smooth ride and temp slightly cooled down and fan stopped

 

[02GF74]

Update, finally installed the temperature sensor and display
Idle, heats up, bike instrument reaches almost red, fan starts when display shows 105°C (221°F) which is the bulb spec, so fine
But temperature won't lower no matter how long I leave bike idle with fan running

So we wonder either some radiators lines not fully flowing
Or the plastic internal gear of water pump which may be broken/loose
Have you checked the plastic valve is is correct position? Can you rule out an air lock? I'm pretty sure you have but you tested the thermostat?

So we'll first try quick install of another radiator to check if fan then will cool water
If not we'll check pump's internal gear

Is it correct that while idle, if I leave bike with fan running it should cool water down, and fan should stop?
Yes, eventually, see below.
Or its normal that fan keeps running with no effect on water temp?
No, water temperature should go down. The rate of cooling depends on difference between the water temperature and ambient air temperature ; obviously if you are in the desert at 50C then it would take longer to cool than if you were in Scotland, at 12 C.

Note that I then went for a smooth ride and temp slightly cooled down and fan stopped
That is correct - the amount of air forced through the radiator when moving far exceeds that what the fan can pull through when stationary. The needle should reach 'Normal' temperature, which in my case is when it is pointing to around 4 o'clock.

 

[MaxMidnight]

Have you done what I suggested in post #91 or was I wasting my time?

 

[Parminio]

But temperature won't lower no matter how long I leave bike idle with fan running

That's normal.

The fan isn't designed to completely cool off your bike while you let it sit still at idle forever and ever. It's to keep the bike from overheating, which it obviously did.

Once you start moving, the bike cools down.

Jesus...

 

[AP76ita]

That's normal.

The fan isn't designed to completely cool off your bike while you let it sit still at idle forever and ever. It's to keep the bike from overheating, which it obviously did.

Once you start moving, the bike cools down.

Jesus...

Yes I was just resorting it to share full informations. Know its obvious but given it doesn't cool down even in 30 min of fan running it could also be no cooling with higher speed air, maybe due to stuck radiator or water pump malfunction

 

[Parminio]

Yes I was just resorting it to share full informations. Know its obvious but given it doesn't cool down even in 30 min of fan running it could also be no cooling with higher speed air, maybe due to stuck radiator or water pump malfunction

Let's review:

But temperature won't lower no matter how long I leave bike idle with fan running

And then

Note that I then went for a smooth ride and temp slightly cooled down and fan stopped

So, once more, it performed EXACTLY as it should.

I am beginning to believe you are looking for problems that don't exist.

Edit to add this post from before when guy said he was having a similar "problem":

Perfectly normal.

Typically, the fan doesn't turn on until right when the needle hits right at the gap between the black and the red area or sometimes right towards the end of the black. If it gets into the red area and the fan isn't running, then you have a problem.

The circled area on this picture is where the fan typically turns on.



It's also OK to run in the thin red stripe area for a little while, but if you ever get to that thick red stripe at the end, turn the bike off immediately.

Most people install the fan switch because they think the Vmax is a car where the fan should run constantly. It's completely unnecessary.