Coolant problem

[Deeluton]

Hi guys

I have a cbr 125r I have flushed out the old coolant and put in new mono ethylene glycol.. the motorbike starts for 2 to 3 minutes then cuts out and wont start for a while.. also the heat gauge has not bars..

Any advice?

[fastbob]

Retrace every step you made when you changed the coolant . I suspect that you may have dislodged a sensor .

[Mississippi Bullfrog]

Sounds like an air lock. Probably best to drain it and refill very slowly from the highest point in the system.

[Deeluton]

So the top of the radiator?

[husoi]

Usually (for bigger bikes anyway) after you replace the coolant fluid you run the bike for a few minutes giving it a couple revup. After this you open the reservoir lid and the radiator cap to make sure there is no air.

top up if needed and fill up to MAX level in the plastic reservoir.

By running the engine for a few minutes you would have forced the air from the system to either the top of the radiator or into the reservoir.

To be on the safe side you can repeat this operation a couple times or until you don't need to top up.

Another point is to make sure you are using the correct cooling fluid.

[fastbob]

So the top of the radiator?

 

Did you only fill the expansion tank by any chance ?

[Deeluton]

No I inky filled the radiator

[husoi]

No I inky filled the radiator

 

Rookies...

[fastbob]

No I inky filled the radiator

 

What ?

[fastbob]

Usually (for bigger bikes anyway) after you replace the coolant fluid you run the bike for a few minutes giving it a couple revup. After this you open the reservoir lid and the radiator cap to make sure there is no air.

top up if needed and fill up to MAX level in the plastic reservoir.

By running the engine for a few minutes you would have forced the air from the system to either the top of the radiator or into the reservoir.

To be on the safe side you can repeat this operation a couple times or until you don't need to top up.

Another point is to make sure you are using the correct cooling fluid.

 

Good advice . The question of whether the tank is a reservoir or an expansion tank or both has been debated here more than once . Personally , I would go with the individual manufacturers instructions on changing the coolant , including running the engine with the cap off until no more bubbles appear and then topping up the tank afterwards . This is the procedure on my ER5 anyway . I was just a little concerned that the OP had made the common mistake of trying to fill the system via the tank only but this appears not to be the case .

[TimR]

https://www.manualslib.com/manual/1244336/Honda-Cbr125r.html?page=167

[husoi]

Usually (for bigger bikes anyway) after you replace the coolant fluid you run the bike for a few minutes giving it a couple revup. After this you open the reservoir lid and the radiator cap to make sure there is no air.

top up if needed and fill up to MAX level in the plastic reservoir.

By running the engine for a few minutes you would have forced the air from the system to either the top of the radiator or into the reservoir.

To be on the safe side you can repeat this operation a couple times or until you don't need to top up.

Another point is to make sure you are using the correct cooling fluid.

 

Good advice . The question of whether the tank is a reservoir or an expansion tank or both has been debated here more than once . Personally , I would go with the individual manufacturers instructions on changing the coolant , including running the engine with the cap off until no more bubbles appear and then topping up the tank afterwards . This is the procedure on my ER5 anyway . I was just a little concerned that the OP had made the common mistake of trying to fill the system via the tank only but this appears not to be the case .

 

Call it a double function expansion reservoir tank

It have both purposes, to allow the coolant to expand when hot and it will keep the system "air free" by having spare coolant available.