Rocket 3 Roadster Possibly Overheating?

[buddazero]

I recently took my bike to the dealership, got a full service, which includes new oil, coolant, brake fluids; the usual. Before I had noticed the bike running extremely hotter than usual, which I thought was due to the lack of coolant. So I took the bike for service thinking that would solve the issue. It hasn’t.

I plugged the bike into Tune ECU, coolant temp rises to 100 C, within 4 minutes. Radiator fan does kick in at 102 C and as long as the bike is idle it stays at that range.

Afterwards, I took the bike out for a ride on a cool night, wishing minutes the heat is excessive. After 30 minutes of riding, I quickly plugged in Tune ECU, and the bike temp coolant is reading at a constant 117C, and even rose to 118C at idle.

This isn’t normal right? Trust me I live in NYC and I ride all the time, and it only gets this hot if I’m in stand still traffic for like an hour. But there’s no traffic, cool night, normal few days, and I’m guessing the bike has been running this hot for quite a while.

I doubled checked the oil and coolant levels, all seem normal.

Can anyone give me any insight on this issue?

Best,

Budda

 

[R-III-R Turbo]

First thought would be trapped air in the coolant system.. wouldn't assume the service did it properly but the problem was there before the service. Still I'd like to bleed the system properly and see if there was any air trapped.

Next would be fan issue e.g. the relay going faulty. But it seems that the fan kicks in at 102°C reliably you say? Been watching it on TuneECU?

Lastly would be some kind of lean condition is causing temperature gain that the stock cooling system can't cope with. But checking this needs an O2 sensor and unless there's a Power Commander or some such gizmo or the ECU has been mapped..

 

[buddazero]

Fan works, fuses are ok, and yes I've been keeping my eye on Tune ECU.

How does one fix trapped air in coolant system? Because from what I experienced, fan is working but its just blowing hot air, thus its heating up the engine and the surrounding tank (according to my research), and yes I've heard that it may very well be a trapped air in coolant system, and yes the problem was there before the service.

Is there anything that I can do to fix it?

 

[R-III-R Turbo]

If the cooling system worked ok before but then not so good, and was due to trapped air, the only way i can see it getting into the system (aside from someone opening the system and not bleeding it properly after) is if the expansion bottle ran dry (say from a faulty rad cap allowing coolant to be pushed out) and air got sucked in.
Radiator caps going faulty is not unheard of on Rocket IIIs.

There's a 10mm head hex bolt just above the thermostat (thermostat is on the front left side of cylinder head, on the other end of the big coolant pipe that comes out of the top centre rear of the radiator).
This is used to bleed air from the head by opening the bolt almost all the way out.

The rad cap is the highest point in the system. When bleeding, with expansion bottle emptied and rad cap removed, one should tilt the bike left and right, ideally with front wheel higher than rear to aid the movement of air forward and up.
The tilting left and right helps move air out and over to escape via the open rad cap/filler hole.
Then prop the bike with a bit of wood, while tilted right - and top up via filler.
Repeat until satisfied all air is out.

The on with rad cap, and fill expansion bottle to the max mark.