Yamaha r125 2012 [Coolant/overheating] problem

[ko5i]

Hi guys,
So week ago i was riding in city was stuck in traffic and the red light popped up but the traffic started moving so i moved aswell and was going [trying not to rev engine to much but kept going because there was no where to stop] and it went off and about 30 min later was riding and the light again showed so i stopped on side and turn the engine off but left ignition on and the fan was like working loud to cool down.
I went home after it cooled and i checked the coolant level and the coolant was 4/5 so it was under full but way above minimum, i checked the hose all the way to end and there was no leaks or so ever.
Today i gave it a go [to college] and i got to college about 30 min riding and there was no light or anything but when i stopped the fan worked for about 1 min and went of, going back to college i stopped on petrol station to fill it with petrol and when i stopped the fan was also working no light anything, and then i went home and there was no light and when i stopped at house there was no fan working on.
But for sure its overheating [or maybe not overheating because the light doesnt come up but its getting hot quicker than before, because during summer i was riding for up to 4 hours daily and nothing and now when its cold weather it gets hot quick.


Question : What should i do/ inspect to fix this heating issue ?
One thing i checked is coolant level and hose if it has any leaks but it doesn't. So what should i check maybe its something with this radiator/fan/air cooler that is in front above front wheel, it has like metal cap and warning not to open when hot and i read also that its under pressure or something so i dont wanna make it worse as i dont know much about this radiator how it works and that so i would rather ask you guys
The red light means 'coolant temperature warning' i checked in manual book
[One quesiton off topic, what gloves would you recommend me? doesnt need to be winter gloves or anything just gloves so they protect and also keep a bit warm. i found '' Scorpion Talon Gloves Black '' they look pretty cool and good opinions what do you think

Thanks for helping !

[MCN]

The engine will overheat if it doesn't cool.
It relies on air flow through the radiator to cool the coolant. (Hot coolant give heat to the colder air).
If there is not enough airflow through the radiator then the coolant cannot lose heat and flows back to the engine hot.
In general, there should be a minimum 10% differential between the top and bottom of a cooling system at normal engine temperatures.
The other issue is a fault in the cooling system regulator (thermostat).
These will be closed to to force coolant back into the engine for a fast warm up phase and as the engine warms the regulator will gradually open and allow hot coolant to flow through the radiator.
If the regulator is not opening properly then the restriction can cause over heating.
If you say the coolant level is correct then the other more serious cause of overheating is probably not present.

Get some Cillit Bang and spray the radiator core with it. It is very good at dissolving shit and shit. The radiator may be blocked with fly bodies or road tar.
Leave it to soak/penetrate for about five minutes and then carefully rinse off with a hose. Don't go mental with a high pressure jet on the radiator of you risk damaging the micro fins and compounding the issue.
Try the bike again and if still overheating you will need to check the regulator Or replace it with a new one (which is quicker).
They are not super expensive and they can fail.
You will need a gasket for the housing and maybe a manual.
Fresh antifreeze/coolant (with a rust inhibitor)

Gloves alone won't be much good unless they are waterproof.
Insulated Goretex or Sheltex are the ones to look for but they can be sort of expensive depending on your opinion.
One thing to consider is cold hands destroy concentration so if you commute then good gloves are kind essential for your sanity.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[ko5i]

Thanks for reply,
So i will try tomorrow [because while checking the radiator i saw like it had many things between these little metal plates so i just like brush them a little but ok i will try tomorrow before going college spray some cilit bang on it wait about 5 min and rise it of with water and i will see if it helps [ i will let you know guys tomorrow ] thanks for helping

[RhynoCZ]

Just a one bit MCN did not mention, there shouldn't really be any air in the cooling system. Air is an insulator, meaning it does not transfer any heat, the efficiency of the cooling system is reduced. But I do not think this is the problem here.

I put my money on the good old paranoia.

I was out on my motorcycle the other day, 9°C to 10°C, and my fan kicked in at slow moving traffic. The fan is so effective, that when you do not rev it like a crazy person when you do about 2 mph, it cools down the coolant enough so the fan turns off, then if needed it turns on again. It's never a constant fan spinning and the moment you get moving again the coolant temp. drops down immediately. That's the huge radiator, I guess. Sometimes it seems the coolant gets too cool at colder weather. I can tell when the fan kicks in by the flow of scorching air penetrating my boots making my feet sweat.

Anyway, the same applies to when it's 30°C+ outside, only slow moving traffic can turn the fan on. It is when the fan doesn't kick in, you've got a huge problem. Also, some bikes are designed better than others. The CB-1 I had ran always hot, the blades of the fan did like 500 miles a season just spinning. Other motorcycles, especially sports bikes, run at 80°C and less no matter what, because those motorcycles were designed to be used at completely different pace.

Is this your first liquid cooled engine? I know I was a bit frightened when I got my first liquid cooled motorcycle. The first month, I was checking the temp gauge more often than the rev counter.
Then a mate told me not to care about it, that it's not gonna explode, just keep the needle of the temp gauge on the scale, I got to know when/at what temp. the fan kicked in and so on.
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[Suntan Sid]

Has the coolant ever been renewed, or is it the original coolant?

Coolant is cheap, cheaper still if you mix it yourself, (50/50 anti freeze/water), drain the system, flush it out with a hose until the water runs clear then refill with new coolant.
New coolant cools better than old coolant, it may solve your problem!
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"Everybody needs money, that's why they call it money!"

[ko5i]

So today morning i sprayed the radiator with Cilit bang and left it for about 5/10 min and then i flushed it with water from the bottle to rinse it of. I turned on engine there was a bit smoke from radiator coming out just for like 10 sec i think the cilit bang was like disolving or something . SO i rode to college at normally [i usually never go over 9000 rps [it has 12000 max] and i stopped after 30 min riding at college and checked if the fan is working and it did worked kinda loud and for like 3 minutes and it stopped so i locked it and went college.
So should i change the coolant/radiator or what buy new one or should i not worry until the red light will come up because for now the light never came up since about week.
edit : yeah thats my first coolant bike, before i had hyosung gt 125 and it was just air cooled i think didnt had any coolant or so ever

[RhynoCZ]

When you say loud, you mean air noise or faulty bearing noise? If air noise, then it's alright, the rad was obviously clogged with dirt/flies before you cleaned it. Now, when the fan spins, the air coming through the rad makes the noise (my fan is loud as well = air noise). The ''smoke'' was not smoke, just the water evaporating.

As for the red-light, I'd find out at what temp does it go on. 100°C is still alright, considering the whole system is pressurized. The boiling point of the coolant is a bit beyond 100°C.
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[MCN]

[ko5i]

Hi, by loud i mean its hmm sounds like its just fan working loud not bearing issue. Could someone tell me whats this on top of rat it has like metal cap with warning do not open when hot, maybe i should open and idk bleed air or something.
Also i was going back home from college with like reving it up to 7/8 and like accelerating 'fast' [on 125cc] but yeah i was riding reving and all and the light didnt came up and when i stopped at home the fan was on for about 2 min and then went of [i cant now remember but before i just used to stop turn of ignition and lock it and go so i didnt hear fan working cuz it only works when ignition is turned on] and now when i stop i usually switch of with key to turn the engine off and then ignition back to on and fan starts on and runs for few min

How can i check temperature

[MCN]

'Do not open when hot' is the radiator pressure relief cap. It is the part that controls pressure in the cooling system.
If the engine is hot then there will be pressurized air (gas) pushing on the coolant and the pressure cap.
If you open when hot the gas will escape and possibly blast boiling hot coolant on your fizog or hands.

There is a detent designed into pressure caps that helps prevent the cap being completely removed. You have to open part way where there is a little resistance. This unseats the valve and pressure can escape. It will release hot air, steam, vapour and liquid.
When the pressure is released the cap can then be removed.
The problem with opening a hot system is that the trapped air escapes so the system will not maintain pressure properly until it has been allowed to cool, the level is checked and the cap then replaced.

Fan control switches can stick which can allow the fan to run-on a bit.

Posh/Pro: You can measure temperature using an infrared thermometer.

or

Ghetto: Tape a couple of 0-100 thermometers to the top and bottom hoses.
If you tape them on they must be in contact with the hose and well insulated from airflow or they won't read system temperature as well.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[ko5i]

Ok, thanks for helping and the link to that thermometer
[Today i was riding to college and it was kinda rainy and i stopped at college and the fan didnt came on i touched the rad it wasnt soo hot it was warm/chill but not super hot] maybe because of rain and it cooled down idk i will keep riding and see if the red light comes up or something
Thanks for helping !