So every enginebuilder says to change oil a couple hundred kilometers after only a pistonchange...? Were not talking complete engine teardown. I love the fact that you write "quality engine builder "
so anything I come up with that doesnt support your facts can be called a bad builder ect... I have a hard time figuring out why you are typing in a public forum, but refuse to hear other peoples experiences.

Anyway, back to it....I bet its still the better safe than sorry situation.... If they told somebody to not do it, and the custuomer had another unproblem with the engine dying and came back with it, he would blame the engineguy for sure. Its not hard science, you know how the oilsystems works, what are you trying to do by changing new oil that gets filtered by a fine papirfilter, which has no debrees in it?

No one on an mx track will do that, but i guess the ones servicing competition-bikes isnt a "quality" enginebuilders ? Theese guys do a LOT of service to keep their bikes up and running, and change stuff long before it breaks. You should see (and meassure) the stuff they take out of their engines and discard.

Fun fact: The Mx-guys run their enigines for more hours on the oil than it would take me to clock in a couple hundred kilometers on my xt600 just commuting... MX spec oil interval for a xt600... hmmm..

So youre saying oil with 1000km on it can look golden, but still be contamined to the point where it must be changed? really?

Oeh, not all cars come with dynoil for break in... Enginebuildermag even writes "Consequently, it should make no difference if a conventional oil or synthetic oil is used for the initial break-in. The deciding factor would be the cost of the oil itself." But I gues theyr're not quility engine builders aswell. They also mention that seating the rings can take as long as several thousand miles. So if you swear by dino oil, you should probably use that again on the following oilchange. (you didnt mention whatoil to use in the post i replied to, so you might wanna ad that, when its so important.)

A guy claiming to have rebuild over 300 bikes, recommends 1500miles before chainging oil, to proper seat the rings.

So theres lots of different oppinions outthere, even among the guys who build and maintain theese bikes

Theres oil made for break-in, some say not to go beyond 1000 miles, and thats not on your everyday dino oil, but oil specifically made for breaking in a completely new engine.

Its weird theres no word about assembly lube, priming the oilpump ect when you try to take so good care about the bike and initial startup after opening it up...

I'd be much interested in the result of you oil analysis. Especially if its oil with a couple hundred kilometers on it, on a bike simular to ours, with only a pistonchange. That would be awesome, but any other will do aswell. I've seen many results on advrider on blokes dualporting their ktm ecx's where they were able to stretch their oilinterval a couple hundred percent.

I'm not sure theres places which does that here. I've actually never felt the need for it, with the bike beeing so reliable.

I do change the oil more often on my wr250r, as it sees much heavier use, and frequent use of riding the clutch.

Oeh, and I actually didnt recommend og told anyone to do it my way, you might wanna read it again. I just posted my experience, so people can make up their own mind. I asked question about your experience, but you didnt answer most of them.

So lets just agree to dissagree, and people can make up their own mind.

That's the thing that kind of flung me for a loop and why I even said anything . I've just never heard of that way of thinking for such a little cost compared to what a person has stuck into the new topend.

Hei! Recently i rebuild my XT ,rebored,new ProX piston and rings.Also i rebuild and my cylinder head,new valve seals. But,when i start-up in the morning i have a white smoke for a 1minute and after that it's okay. Compression is about 140+psi.

Do you have some king of problem?

I have not completed the build as yet. How many miles do you have on the new engine since rebuilding. It may be that the rings are not fully broken in (seated in). 140 lbs of compression does not seem to be high enough for a new engine, again maybe it is not broken in yet. My 86 xt has about 15000 miles, never been apart and has 170 lbs compression on a new gauge. That is the top of expected compression range of 150 to 170 lbs.

Time will tell you if your rings are seated properly. Monitor oil consumption closely. My 84 continued to burn oil after the last re-ring. It would puff smoke at startup and on deceleration. This is why I pulled it down again and bored to 2nd oversize and new OEM piston and rings. Clearances are now factory spec. Hopefully I can get the rings to seat.

Once I get it together and running, I will take it on the road and not idle it in the shop. From what I understand you must start the break in process quickly while the cross hatch in the cylinder still has sharp edges.

There are lots of opinions about break in procedures. I will not go into that here.

I welcome anyone to jump in here with some wisdom. JJ, your experience here could benefit all of us since you have built many engines.

Steve

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'84 XT600 is now bored to 2nd oversize and new OEM pistons and rings installed. No more smoking.

Side question

What are you guys doing to monitor engine temps? I'm looking to add a gauge.
ex:Gauge

JJ has just the ticket, he will jump in here with his solution and why. The spark plug gasket method is no good, will show a way too hot of an indication. JJ puts the sensor into the head so that the oil bath inside the rocker box helps determine the temp.

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'84 XT600 is now bored to 2nd oversize and new OEM pistons and rings installed. No more smoking.

I'll have to wait till I get home to post a pic of the location I found for the most responsive spot for reading true head temp. I use those TTO's but am really thinking they're POS's . None of mine work below 40-45ºF, the screens just blank out. The Vapor unit is best but more $$ and more stuff than needed if a person already has stock gauges. If you don't worry about the cold issue, the TTO's work , but you need the one with the 6mm x 1.0mm threaded probe.

I have an oil temp gauge instead of the dipstick. I think it reads oil at its lovest temperature, and it meassures the return-oil.

The temp guage will just give you another thing to worry about, I know I dd at first...

Here's where I put my probe in my XT's , This location measure the oil temp right above the right side exhuast valve , the hottest part of the motor and it'll show the quickest if anything is going wrong . I just see what it reads normally and if it suddenly goes higher I'll know to check things out .

Do you have pictures of the gauge?
You have it set up to monitor the bike while driving correct?

Thanks

I have both TTO gauges and Vapor unit for seeing the temps, depending on which bike . They're on the handlebars or dash to see while riding at anytime.

Trailtech TTO temp in eBay Motors | eBay

or the Vapor , trail tech vapor in eBay Motors | eBay

Which adaptor do you use? Seems they come in different variations ex: for spark plug or radiator.

I use the 6mm x 1.0mm probe exclusively . I had 2 of thoe ring style probes and placed them all over the motor and none came close to as consistant and accurate as the probe in the head. I had 2 TTO's on 2 bikes all summer a few years back to directly compare . Usually had 25-50ºF difference .

Thanks a lot

curious to what temp #'s it runs at and what is considered max temp for these motors.

I usually had 250-275F on my mostly stock motors @70F air temp with the probe inside the head. The other style of probes would vary 210F to 240F and fluctuate with wind and outside temps quite a bit , plus take 4-5 times longer to show changes(like stopped at a stoplight then to moving). Hotter the air temp temps went up a bit. This is the reason I like to use synthetic oils in the aircooled motor , standard dyno oil begins to breakdown at 250F , synthetics are designed to withstand the higher temps , but I imagine it takes quite a few miles for the oil to get bad enough to not be up to the task. My high
comp motor see 300F regularly on trips in the warm summer up to 330F.