They also run lean which makes them hotter. To date, with my own eyes I've seen one siezed and one bottom end failure on Bullet Sixty-fives that the owners ran on UK motorways for extended periods. One was a 2004, the other (I think) 2007.

Nikasil in this case is a bit of a red herring, it's a hardening process. A cast iron bore had to be made under size to allow for the wear. The engine started with a tight bore, was run in then lost compresion over the cylinders life. It always ran hot either due to friction or working harder to make the same power with the worn components. The nikasil bore is made the correct size (hopefully) and then keeps it for longer. This helps in that the fits are correct, so only the required amount of heat is produced, but it doesn't help an engine run at full power with no way to get rid of the heat except convention past the fins.

Yes there have been serious changes (in the oil circuit too), but are you saying the Electra/AVL will run 250 miles in under 4 hours day after day? No one seems to be able to give me a straight answer on that one as I can't find anyone using the newer Bullets except as weekend toys, running them just like the cast iron engines.

Yamaha XT's burn oil when used on the motorway, another pure aircooled design that simply can't get rid of the heat, it isn't restricted to the Enfield. BMW's, Harleys and Triumphs don't do it because you are only taking 25 HP out of a motor designed for 50-60 HP while the singles run full tilt. A Harley's biggest issue is cooling the rear cylinder at idle, hence the newer ones idle on the front cylinder only, again they simply can't get enough air to flow past where the heat is.

Apologies if I somehow denegrated your personal choice of bike, but there are designs much better suited to the motorway.

Andy

Your XT will be fine !!!

Its aircooled but designed as such.. Massive cooking heatsinks surrounding the bore's sucking heat away, the motorway is the BEST place to be !!

The engines are pretty low tuned too to what they could be if they were water cooled..

Like said, replace the filler cap with an temperature guage cap and keep an eye on it..

Your oil probably isnt even going to get to 100c when cruising on a hot day. The hottest my oil got was 130c in Brazil in thick slow traffic and it still looked and smelled good 3000 miles later. (XT600E).

Modern synthetic and semi synthetic oils can take high temperates very well !! Just make sure you always use good quality oils and change when you're meant to.

Stop worrying !!!!!!!!!!

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

The sixty fives use the old 1938 engine, not the AVL, but they do have the five speed gearbox
The AVL does run hot, I advise you wait some considerble time before putting naked hands anywhere near the exhaust system


The AVL motor has an aluminium barrel nicasil plated, same as the BMW's and they seem to cruise well enough on motorways. My old one did. ( I think, but am not sure that the barrels (nicasil) for both BMW and Enfield are made in the same factory in India, as are the pistons and conrods for mercedes, porche and MAC trucks, among others.

It is too soon for me to answer that one as I have not yet done 2,000 miles with it. However I did run it to/fro the UK . left here in 35c after about 150 miles around Rennes I ran into bad weather. It ran that without any problems. Also on the way back was rain until Rennes then 30+c sunshine. This meant I did 150 miles in rain and 150 in warmer weather ie 300 mile seach way to the ferry port..
Yes I bought it to poodle about locally with the odd camping trip. I have to say I am a little shocked by how much they have optimised this build for motorways, to the point I will be undoing some of them. It likes 55-60 and really dislikes running below 50mph and at a constant throttle for that speed, it will slow going up hills and speed up considerably going down. I do cruise slightly slower on it than the BMW, but this is because it is naked, and not fully faired. My times from place to place are pretty similar, but then I do not habitually ride fast. Your 250 mile trip on the Enfield will not need a fuel stop, as over the 900 miles of my trip it averaged 94mpg. So had a greater range with its 14.5 liter tank than my BMW had with 20+.
At some point I will invest £160+VAT and get myself an 18 litre tank. This will give me aound 350 mile range to reserve.
You are right, this bikes forte is not the motorway, and there are many ( probably most) that are better. But it will cope. I prefer to use quieter roads, but there are times and places where the only sensible option is to use motorways and by-passes, the enfield will do it.
I would say my BMW was better on the motorway, apart from frequent fuel stops, but worse every where else. The fuel stops equalises the transit times between points. Getting off the ferry, I was able to do a U turn across the width of a single car, so made my exit some considerable time before any of the other 20 or so bikes there could. Only one of them later passed me at bout 40-50 miles on.

You did not denigrate my choice of bike, as you were talking about the 1949 model. It is just that this advice is not entirely correct now. You need to separate the old bike, the Electra X ( now no longer exported) and the new efi unit construction Enfield, of which I have very little knowledge or interest, as it cannot easily be converted to RH gear shift.

UPDATE: Today I discovered that my bike is fitted with a one tooth larger gearbox sprocket. This makes sense because it feels overgeared. You now need to change all the speeds downwards by 5.5%.

Morning Horses,

well my trusty Yamaha XT250 Serow's covered over 67,000 miles, in 3.5 years worth of riding and gets plenty of distant Motorway type use. I find that if I keep the speed to 90kph, that the economy remains OK but, if I stretch it to 100, then she feels a little stressed and drinks more fuel.

The oil capacity's only 1.2 litres. so I perform oil only changes every 1,500km, followed by oil and filter changes every 3,000km.

[quote
The oil capacity's only 1.2 litres. so I perform oil only changes every 1,500km, followed by oil and filter changes every 3,000km.[/quote]

For comparison the Bonneville takes 4 litres every 10,000 km.

Andy

I had a '94 XR250 for a year..... Ran really nice all types of roads/terrain.
I did change oil every 1000 miles, semi synthetic mineral oil.

As for air, oil or water cooled.... they are all designed to work as manufactured. Personally, water cooled is added complication & risk of leaks so I prefer air cooled.
I also run a couple of Kawasaki Z1000's an early 70's design... 11.5 sec @ 116mph - over 1/4 mile...... and



also ran it to York & back this summer, 650+ miles in a weekend, no probs

Any bike thats looked after & not treated like sh*te should be fine