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Old 10 Jan 2010
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Exclamation africa twin - in africa - over heating!? please help

due to a blown enging on my xt600 at the last minute i bought a 1995 africa twin in very good nick of a mechanic who had looked after it well and was confident it was ready for a big trip - i also had it serveced befor it went.

contery to all advice am am now in morroco on a bike that is completely knew to me and i am having strange issues which are bafiling, here they are, some may be normal but something dosent feal right...

on the way down the temp guage stuck at just above 0 for 500k at 80mph..

i worked out it was doing 30k per gallon with me and a few heavy bags..

3after the last houre in heavy mad marakesh trafic the over flow on the water system burst out a load of water

today i traced i worked out the fan thermostat wasnt working si i have wired in a switch.
however it is still rising up to half way up the thermometer, whereas yesterday it stayed near 0. and it says in the manuel the fan is for extreem heat conditions, which marakesh at night in jan isnt really...

on the last legg high up the mountain it kept dipping in power if i let the reves get to high... although im hoping this is lack of oxygen from altertude rather than conected to the rest of it...

i have also noteced it sounds more ratelly than it did...

i am a bit nervous about takeing my bike too far from a majour city like marakesh in this state... has any one got any advice? be really good to tslk to someone whos done a trip on an africa twin, mine is the xrv750 1995 model

many thanks Pip nomadrush_@hotmail.com
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Old 11 Jan 2010
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I'm not familiar with the AT but we've had a similar problem with F650GS here in India. I would remove the thermostat,it sounds like it's stuck, it isn't going to cause any problems unless the weather gets really cold and if it does you can always block off part of the rad with some cardboard. The GS rattles when it's really hot!

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Old 11 Jan 2010
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africa twin - in africa - over heating!? please help

Hi Nomadrush,

First advise is….STOP…. The may be nothing wrong with your bike the gain there might be.

All things at the moment seem water related. If there has been a gush of water and steam from your overflow you may very well have a blocked radiator and these needs to be serviced immediately if that is the case.

Low temperature may be that there is no water around the temp sender unit …..running bike without water is not good for it.

STOP …Stop it is time for maintenance all machinery needs it you don’t need to blow up another bike. Servicing may not include the removal of and cleaning of the radiator 199to 2010 is 15 years and the radiator my not have been removed in 15 years

In the spirit of trying to be of help to you I would suggest the following

The interoperation of extreme heat conditions should be interoperated as though the bike were in heavy traffic conditions stop start traffic or on the other hand the climbing of high mountains put the engine under extreme load or working conditions and causes friction … heat!!!

In your e-mail you say on the way down the temp gauge stuck on 0 for 500k

Did you not go up the mountain first and perhaps the engine overheated and disgorged (threw up) out the overflow. How often do you check the water?

On the way down does that mean from UK to Morocco????

Your bike is water cooled so water surrounds the cylinders and head to keep the bike cool

This is what I would do:-
  • Firstly check the engine oil and see if there is any water in the oil: check by draining a small amount of oil from the drain plug…..If it is milky then you may need some other answers. Water nay be keaking into your engineThrough a head gasket or crack I certainly hope not.
  • The coling system is very importantv to the running of your bike
  • Yes by all means remove and check the thermostat …. If it is jammed open this should be obvious the top part will be raised from the bottom part not so bad except to get your bikre to correct operating temp
  • it can be jammed closed as well…….this can cause overheating which is not good
  • Test… Place in boiling water and observe that the thermostat opens if not …. It is an important part to keep your engine operating at the correct temperature; if your engine is not operating at the correct temperature then it will cause problems
·Importantly the radiator must be working properly and the fins must not be blocked externally by mud or other contaminants.
·The internal part of your radiator must not be blocked one and one only blocked tube can cause overheating. It is a small radiator …. …..Take the radiator to a radiator specialist and have it cleaned.
·Now the fan switch this must be working properly as you the driver can not take the place of the sender/sensor unit and turn the fan on and off when the engine requires it. the fan will turn on automatically when the engine reaches a required temperature the fan will turn off when the engine cools to the right temperature.
·To Check if the temp gauge is working properly obtain an aftermarket temp gauge that can be fitted to the bike and do so this is not meant to replace the gauge that you have but is a piece of test equipment to check all is going well

In all fairness to your great Africa Twin do the servicing procedures before you continue and let us all know the outcome? If you’re not sure take the bike to a mechanic or ask questions on the HU site there are some people here with a lot of experience and you can judge for yourself.

NB…..After you have drained any water from the bike flush the engine part wit a hose of high pressure to wash out any scale or junk that has accumulated in the water jacket and when all is back together refill the cooling system with a good quality recommended inhibitor/anti corrosion and anti freeze if in extremly cold conditions

Low power at altitude is kinda normal
But overheating is not

Thanks for the opportunity of being able to help and look forward to your reported outcome
Kind Regards

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Old 13 Jan 2010
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I think that you have kind of answered your own question, the bike got hot & boiled over. You then realise that the fan thermoswitch isn't working & wire in a manual switch......

The fan thermoswitch is on the bottom of the Rh rad, take the wire off & short it to earth with the ignition on, the fan should operate. The thermoswitch virtually never fail but the connection corrodes.
If the fan does not operate by doing this, try & spin it by hand - they can 'stick' if not used for a while, then check/repalce the fan fuse and short the wire again to check.

These bikes often run low on the temp gauge & only get to the mid range in warmer climates/ higher load etc.

650 Transalp
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Old 15 Jan 2010
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thanks so much for all the advice, amazing resource this, got allot back from xrv website too.

So, i think i don’t have a blown head gasket, and the thermostat and pump are working ok because the temperature gauge is doing what it should (staying low on the open road, and rising to 3/4 in traffic with the fan manually switched on).

So it’s either the switch or the wiring me thinks...

Right at the start, when I was looking at the switch the earth connection (green wire from the connection block which is mounted behind the fan to the frame, The other black / blue wire from the block goes strait to the thermo switch and then the fan motor) broke off very easily and the spade was very corroded.

I couldn’t work out where the wire broke from, but the Manuel says it is the earth wire, so I re earthed it to another bolt on the frame.

at the same time I ran a wire from the fan thermo switch, through my own switch and to the same new earthing point id used for the green wire.

when i turn my homemade switch on the fan comes on.

When i let the bike heat up it goes in to the red still without the fan coming on automatically.

So my conclusion is the switch must be gone right? Although people say it’s unlikely to be the switch otherwise it must be because I have earthed it to the wrong point and the green wire should join something else...

If any one is very familiar with the bike they might have some rough idea what im on about! if not good to get my thought process written down in english...

I especially liked the advice about threatening the bike, I told it id swap it for a camel if it didn’t behave... then a morocco kid rode over and offered to swap it for his ropy c90 scooter, and i think the bike laughed at me.
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Old 15 Jan 2010
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HI Phil,

Without being able to run the bike and experience the same symptoms as you it is not easy to diagnose your problem correctly however if all the things I mentioned are right then hopefully you should not have problems.

The designer meant for your thermo switch to be working and being light:-) hearted along comes the accountant and puts a switch in the system without understanding the function:-), yes this is ok in an emergency and as far as the engine is concerned it would be better to have it cool rather than overheat the alloys in your engine which may cause them to soften and cause all sorts of problems. That’s from a mechanics point of view.

If you have doubts about the sender working properly then this can be tested. Obtain a cheep electrical tester and set it up in the earth wire, the green wire to one end and then earth the other end. Run the bike until it heats up The globe should come on when the switch closes to turn the fan on. An auto electrician will have a method of testing this it is quite simple and can be tested in hot -boiling water remove the switch attach wires and a globe or test lamp in the system. attach a MC battery to one wire on the switch and earth the other to the battery
drop the switch into a pot of heated water the switch should cause the lamp to come on. I did thhis witv my race car when I set up several switches to operate several fans at different temperatuers.

The indication that your wires are in poor condition should not discount that the rest of the cooling system may be in the same condition.

Check out the following “Google Motorbike Radiator overheating” don’t worry that this is a different bike the information is the same and the principals of how they work are the same. Try Goole with as many different searches and take in all the information available.

This is one post worth considering ...this site gives a list of checks that you should make

Motorcycle Repair: GPZ600R over heating, radiator fan, apear radiator fan, apear, thermal sensor: Hi Kevin, Q: ...I have flushed the

In the spirit of yours and your bikes best interest before you go anywhere ensure that your cooling system is working correctly.

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