I don't get a good reading of oil level easily on my 4PT. I ride the bike round for five minutes, then come back and check the oil level is not overfilled. Then measure the quantity of oil drained, and refill with the same measured quantity of fresh oil, then ride round for 5 minutes before checking and topping up if necessary.

I run fullsynth all the time. 10w50, and 5w40 in the winther.

I've un a lot of different brands, witout problem.

Fullsynth is better for high temperatures, and it degrades slower than semi synth and dino oil.

Its a religion, luckily the xt ist fuzzy about using a specific oil.

My reason for using semi, not synth, is that the synth is known to cause clutch slip in some bikes, with some oils, and the semi isn't.

If you know your bike has no problems running on any synth, or on a particular synth which you can always get you hands on, then there's no reason not to use it.

If you don't know that and you're in a place with a limited choice, then a semi is the safe choice.

If the only bike shop in town only has synth in stock, then use it. It will probably be fine, but if it does cause clutch slip that is nothing you can't live with for a few days until you find another oil.

Semi does degrade quicker, but so long as you change the oil at the correct intervals, this shouldn't be an issue.

The point of this post is to assist the OP in making a decision, the OP is never going to get universal agreement and a firm answer from a forum, but if people post their reasoning, at least then the OP can read it and decide for themselves what they agree with.

I concurr with Mark. Do not use Fully synthetic oil, use semi.

Synthetic buggers up the clutch.

When I couldn't get hold of a motorcycle oil abroad I used car multigrade on my XT. As long as its got the right numbers and letters it'll be fine.

Any old oil is better than none at all!

Dan

You know that semi synth is a mix of "real" synth and dino oil right? For me that would be like taking my favorite , and mix a cupful of bud light in it

Google "oil myth" or something like that. Fullsynth is better on the paper. If youre bike dont like, fine. But that doesnt meen everybody else cant use it.

As to the clutch, I've got over 96.000km on totally stock and unopened engine, so it cant be totally bad, huh?

The main reason for me to run what i consider "the best" type of oil, is that I know its the most capable of handling high heat, which you can/will find in an aircooled engine. The 2nd most important thing for me, is that it takes longer to degrade.

I still change often, oil is cheap. A few extra bucks at the end of the year, saved by using what I consider a lesser oil, do me no good if my engine is blown. It would really suck for me to have any type of engine malfuction, it would have me wondering if a better oil could have done something about it.

I use the bike as my dayly commute, and for enduro-ish type of riding. I need it to be reliable.

Yes I am aware that semi-synthetic oil is basically mineral oil with additives.

I can only speak from experience and from others whom I know personally, who have a vast experience of bikes and particularly XT's, and who I trust and respect have told me.

Synthetic oil can penetrate the clutch plates and cause them to slip.

Semi-synthetic oil has been treated to give the molecules longer chains so that they take longer to break down.

Mineral oil is fine but you have to change it more often.

I have worked as a Motorcycle courier in London, quite hard word for an engine and I used bog standard mineral M/c oil but changed it every 500 miles.

When I couldn't get hold of bike oil I have used car multigrade.

My bikes are all fine. If you find that your bike runs on Synthetic oil then use it, but I wouldn't put it in mine. Unless there was nothing else! Any oil is better than none.

Dan

Good post, I think we agree that its religion, and not every bike likes the same oil.

We should just make a poll, and refer to this thread for future use =)

I agree do NOT waste money on expensive synthetic oil. ANY good quality MOTORCYCLE oil is just fine including plain mineral oil. What is most important is regular oil changes - the more the better for the engine.

Mine get oil changes at 1,000 miles. Oil is quite cheap compared to fuel...

I put Semi-Synthetic in mine because I got a good deal. It was German made stuff. If it's good enough for the krouts it's good enough for me bearing in mind they are by far (in my opinion anyway) the worlds best engineers.

I have known of people who put car engine oil into their bikes with dire consequences - Don't do this unless in an emergency to get out of a temporary fix. Put the right stuff in at the earliest opertunity afterwards.

With an XT is always best to keep it simple - just like the bike.

__________________
Triumph Bonneville 800 (2004), Yamaha XT600E (1999), Honda XBR500 (1986).

Heh a friend of mine runss car oil in his suped up 1980-something xt600, with high compression piston,another camshaft and pumper carb. It pulls like no other xt. So, it can be done (I wouldnt, but still, some have had no problems)

The manual calls for oilchange at 6000km (4000 miles ish) and that was in 1990, with whatever oil was on the market back then, a good 20 years ago.

It seems funny that fullsynth is "too good" but then you change oil at 4 times the rate :confused1: If you have full confidence using the oil you use, why change it so often, what do you expect to gain?

One would think that with the interval they wrote in the manual, they would be übercautios about the intervals, to avoid lawsuits and broken down bikes all over the world.

I know that my bike doesnt set the example of every bike out there, but its closing in on 100k km. If I vere to change oil at every 1000miles I could have bought a spare bike by now, if I instead changed at 6000km.

I do hovever change the oil at smaller intervals that the manual calls for, but not anywhere 1000miles, seems crazy to me.

For comparison: KTM 450exc have 15 hours serveinterval at race conditions, thats 15 hours of just over 100km/h. So youre close to ktm race engine serviceintervals, and they only have around 1,2ltr of oil, and puts out way more power than our engines.

I know I know, we agree to disagree, would just love to hear some of the thoughts behind the obsessive oilchanges.

Thx for a good dialog so far to everyone.