Cooling system?

dogpile

How can I tell if it's working or not? I had a leak in the rad a while back that radweld seems to have fixed, now my fan won't work and the engine seems to heat excessivley, got caught in a downpour yesterday and steam was coming off the top of the rad like a fire had been put out I checked the fuse for the fan and it seems alright...any suggestions

jellikit

Its most likely your thermostat thats not working, You didn't say what type of bike you have but if its a yamaha its more than likely that. Every liquid cooled yam I had I bypassed the thermostat and put in a manual switch as I always found that by the time the fan cut in the bike was well overheated and pissing coolant all over the place. With the manual switch you can avoid this and switch the fan on if your'e stationary for any length of time

dogpile

Its a Kwakker ER500..so where do I find the thermostat?

Hotblack Desiato

jellikit wrote:

Its most likely your thermostat thats not working, You didn't say what type of bike you have but if its a yamaha its more than likely that. Every liquid cooled yam I had I bypassed the thermostat and put in a manual switch as I always found that by the time the fan cut in the bike was well overheated and pissing coolant all over the place. With the manual switch you can avoid this and switch the fan on if your'e stationary for any length of time

The thermostat doesn't switch the fan on, it shuts off water flow to the radiator when the engine is cold.

You're thinking of the cooling fan switch.

To the OP, this is a small switch on the radiator. Unplug the connector, bridge the two wires (on the connector not the switch) and turn on the ignition and the fan should run. If not, check the fan isn't stopped from turning by mud/debris, check the fuse and any relays in the fan circuit. Wiring diagram and electrical knowledge will help a lot there.

You shouldn't need the fan though unless you're stuck in traffic, with the bike running at a constant 30mph or more it should have no problem keeping cool. Check radiator fins aren't full of crud. Check coolant level in expansion tank (usually under seat), should be at the UPPER mark, AND check that the radiator itself is full to the brim - don't remove the radiator cap if the engine is hot as it's easy to get scalded by escaping water/steam under pressure.

Radweld is usually a bad idea as it can block the narrow passages in the radiator - either get a leaking rad soldered by an expert or replace it (try a breakers.)

dogpile

ninja900 wrote:

To the OP, this is a small switch on the radiator. Unplug the connector, bridge the two wires (on the connector not the switch) and turn on the ignition and the fan should run. If not, check the fan isn't stopped from turning by mud/debris, check the fuse and any relays in the fan circuit. Wiring diagram and electrical knowledge will help a lot there.

Cheers I'll have a look, it's just that the fan always used to kick in when I turned off the ignition especially in this weather... anyway I downloaded a pdf servicing manual thats like a Haynes manual, diagrams and pictures of every part on the bike, excellent

jellikit

ninja900 wrote:

The thermostat doesn't switch the fan on, it shuts off water flow to the radiator when the engine is cold.

You're thinking of the cooling fan switch.

Yep, thats what I meant.(hangs head in shame). Dogpile, I should point out that these shouldn't be too expensive from a breakers as opposed to the consequences of fitting a manual switch to the fan and then forgetting to turn it on! The bikes i did this to were just winter hacks that I didn't want to spend money on.