We'll be heading through the stans at the height of summer on '02 XT600Es.

Do I need an oil temp gauge? I've got other things competing for the £35 it will cost.

The following questions will demonstrate my thorough lack of knowledge, but I'd be grateful for any answers from those who are a bit more competent...



What damage happens when the engine overheats?

Will a dipstick temp gauge actually be of use preventing that?

If it gets too hot, is simply switching off the right thing to do?

What temp constitutes "too hot"?

When it gets too hot, will there be other warning signs or is the damage done by the time they appear?

Is a dipstick gauge actually just a distraction that I won't be able to see or will forget to look at or will look at when I should be looking at the road?

Thanks!

You don't need one but they come as standard on a car so they must serve a purpose. Perhaps they are more useful on water-cooled bikes as an unexpected rise in temperature is an indicator of problems such as loss of coolant, blocked radiators etc. as well as a lack of oil.

I'll leave 'too hot' to the engineers here but 'above the normal operating range' is a good guide and a gauge helps with that.

If an air-cooled bike is overheating e.g. in traffic, then getting it moving faster is usually the best cure and a gauge will confirm that. If you can't get it moving then you should switch it off.

I've had a gauge on both air and water cooled trail/off-road bikes and after a short time I got to know exactly what temperature to expect in various situations such as riding in sand, traffic or on a motorway. I glance at it regularly, usually at traffic lights or on top of a dune, and I value the information it gives me.

If I were you, I'd tell someone who loves you what they could buy you for your next birthday.

Have a great trip.
Stephan

Maybe you should buy Chris Scott's book it tells you all about it in his book and says water cooling is superior.

You aren't supposed to need one if riding above the tropic of cancer , however you are riding through North America , central America and South America. I don't need one as I finish in Vladivostok (I have same bike as you).

Perhaps you ought to fit an oil cooler to your bike? , you can find them on ebay for £15. While you are riding through Russia you can cover it to prevent it from overcooling your engine, an oil cooler will also increase slightly the oil capacity giving a bigger heat sink.

The XT600E has a bit of a pants design though in that the oil tank is in the head stock which melts the bearing grease which causes accelerated wear.



What damage happens when the engine overheats?

It will likely cut out and as an extreme possibly seize the piston in the barrel causing you no end of grief. Or possibly warp the valves , but don't worry the XT600E engine is the old lump based on the Tenere and those engines will run (albeit poorly) with damaged valves and even badly worn rings.

Terra circa apparently overheated one of their DR350s and it needed engine out in Russia. But when they first went round in Mondo Enduro their bikes were fine and didn't make any mention of an oil cooler.

Will a dipstick temp gauge actually be of use preventing that?

Maybe in that it'll give you a bit of a warning before it gets too high giving you the ability to cool it down before it starts to get too hot. But there are warning signs ie the bike will start to run poorly and due to convection you will start to cool on the bike.

Or just try not to get stuck in heavy traffic ie leave town very very early in the morning , and arrive late after the typical rush hours.

If it gets too hot, is simply switching off the right thing to do?

Maybe.... in that as said above once you turn it off the oil stops circulating for the XT600 that means the tiny amount of oil going round the engine has to vent its heat to the engine which the engine vents the heat to the air , if you keep the engine on with the bike facing the wind it circulates oil to the sump near the head stock giving more surface area to cool down. I would probably ride fast to cool it down , or if stuck in traffic fight a side road somewhere to ride up and down to cool it THEN give it a rest.

What temp constitutes "too hot"?

Depends on the oil mineral oil will decompose and break down into its elemental strings at over 115c, full synth which my XT has decomposes at 125c , since the red line on my CBR is 100C , I would hazard a guess at 95-110C being the red line. My CBR in Spain constantly had the fan on the radiator but only when stuck in traffic and consequently I avoided traffic instead. This is probably why on aircooled bikes you are supposed to change the oil a bit more frequently.


When it gets too hot, will there be other warning signs or is the damage done by the time they appear?

Oh yeah the bike will run poorly , and the bike may die suddenly for no good reason due to vapour lock (where fuel is heated inside the fuel filter that it causes an over pressure inside which blocks the flow of fuel to the carb), it you get vapour lock stop push the bike and let it cool off.

Is a dipstick gauge actually just a distraction that I won't be able to see or will forget to look at or will look at when I should be looking at the road?

It will only overheat if you are stuck in traffic for a long time as long as there is airflow and you are not riding through the Danikil where there is a phenomia called the fire wind (which varies from 40-57C) there will be a temperature differential which will in theory cool the bike.

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Just getone, its pennies compared to the frustration of a broken engine in the middle of nowhere.

It also tells you when the bike is hot "enough" to ride harder.

The red line onmy xt600 from 2003 is at 120 degrees celsius.

With a 10.000km service interval, you can easely change oil a bit sooner, without ruining your bugedt.

Uh, and Im from Denmark with a 180% tax on vechicels.....If I can afford and oil themp guage, so can you.

Oh and BTW Welcome to M & P do them for £25 + 4.99 postage so there is a £5 saved right off.

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Kennichi et al: Thank You!

And that saves me £11 cos there's a £6 delivery charge for the other one.

Superb!

Say you selling an exhaust? , I've got the stock Yam XT600E zorst which looks heavy , vulnerable and a bit rotten.

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Only if I can find a cheap replacement, which doesn't look good so far.

i'm traveling with a TT600R from alaska to ushuaia. before leaving i put some thoughts in having an oilcooler and/or dipstick. I went for the dipstick only, just to have a bit of an indication about the oil temperature. besides, an aftermarket oilcoolerkit with thermostate was eur.250,- and i figured that by now yamaha knows how to make engines and if its neccesary, the'd probably put one on.

as described earlier i also glance at the gauge to see if it points out the temp i expect in several conditions. it showes constant 120C even in death valley in summer and Baja. city traffic causes rising to 130 though.

the only time it hit 140C was going up from batopilas in copper canyon.

i'm still wondering if the indicated temp is too high, the dipstick is at the same point the hottest oil from the engine returns to the oiltank which gives me the idea that the average oiltemp is actually lower. as a precousion i change my oil every 4000-5000 km since too high oil temps will break down the oil.

so far so good, but next time i will put an cooler with termostate on, i think it will keep the oil in better condition and therefore the engine. and it gives a little peace of mind too....

cheers from costa rica.
sanderd

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I used one on my XT600E...

Through Brazil it read 120C at times which did nothing except scare me !! LOL

Modern synthetic based oils are more than capable of tolerating these temperatures so do you really need one ???? No, probably not. ! Looks cool though

David Lambeth said he regularly used XT's in the desert at very high temperatures and sent off oil samples for checking. He said that they were fine (although I don't really take much of what he says with any confidence... hes only happy when making money from nervous travelers)

On a water cooled bike it would prove more effective as it can tell you if your cooling system is still working properly. The temp gauge only registers the water temperature which isn't going to heat up if your thermostat is sticking etc.

As for the oil melting the grease.... NAHHHH !! Not unless your using cheap crap grease... Plus, the oil doesn't actually circulate the bearings on the XT600, I think its the BMW F650's your thinking of.. Those beemers were designed by monkeys.

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Did some trips.
Rode some bikes.
Fix them for a living.
Can't say anymore.

Might be a bit late but I had a word with Ross and he effectively said no, in that all it will do is worry you and you can't do anything about it.

He said the cure was this to buy a different temperature rated spark plug , the standard NGK sparkplug is an 8 , he gave me a 9 spark plug for any super hot sections I have to do , and also a 7 for when it gets really cold.


He said it is a marketting gimmick in that most people these days having lived with watercooled bikes are used to seeing the temp guage on them. And that he has ridden across the Sahara on a Suzi goose and never managed to overheat it, he just changed the plug more often and checked the oil twice a day.

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