This may have been discussed before and I will read through the old threads, but someone may want to give an update ? I have the opportunity of buying a very low mileage 2003 XT600 air cooled or a more newer (even brand new) water cooled XT660. I would appreciate any opinions on the differences between the two. Not sure on what long distance trips I would use it for, but Norway and also North Africa are possibilities. Are air cooled bikes a liability in extreme heat ? Are water cooled bikes more reliable and cope with poor fuel better ? Thanks.

Not too sure on the 03 air cooled bike, i didnt think yamaha made a 660 air cooled one i think it was only the 600 they made but anyway. I have a Yamaha Xt660R just got the other week and it is very good, soild type of a bike. The water cooling does have its ups and downs but i'll give you my 2 pennys worth anyway.

Air cooled engines have to have higher tolerances in parts so therefore have to be able to run on a larger temperature scale, where as a water cooled engine once it gets hot the fan comes on and cools things down (supposedly). Therefore on a trip that you might be seeing alot of very hot weather riding ie 40 oC or plus (maybe africa depending on the time) i think the water cooled would be better for this type of riding. But saying that riding through traffic on my XT660R i find if sitting with the engine running it does pour out some heat, cooking my legs and other bits. No lights or anything come on its just that it is mind winter now and it is nice to have a bit of heat but in summer it could get very sweaty and this is the water cooled versus not an aircooled one which would literally cook me.

Hmm fryed pork.

Also if you are looking into the Xt660R which is the water cooled versus you may want to look into this website. Great site, lots of info, people of nice people and some nice pictures of bikes

.: XT660.com - The #1 XT660 Resource :.

Hope all this helped