No need to break in an engine unless it has a new engine. The bores, rings and crank bearings will have been broken in when it was new. No problem using synthetic as it was broken in when it was new.

It is better to have it running (idle) on flushing oil before changing the oil.
I have allways used regulair oli in my K75, K100 and K1100. It is better to change the cheaper regular oil more often, instead of using expensive synthetic oil.  
Sorry for my poor english.


Grtz., Paul.

"I have allways used regulair oli in my K75, K100 and K1100. It is better to change the cheaper regular oil more often, instead of using expensive synthetic oil."

That may be your opinion but is the complete opposite to mine. Better to use modern synthetic oil to save engine wear and to protect your engine should it get too hot for some reason.
Why save a bit of money on old fashioned oil when you would not do the same and buy cheap old fashioned tyres?

bikerboy wrote:"I have allways used regulair oli in my K75, K100 and K1100. It is better to change the cheaper regular oil more often, instead of using expensive synthetic oil."

That may be your opinion but is the complete opposite to mine. Better to use modern synthetic oil to save engine wear and to protect your engine should it get too hot for some reason.
Why save a bit of money on old fashioned oil when you would not do the same and buy cheap old fashioned tyres?

Regular oil old fashioned??? Bull***

paulbmwk wrote:

bikerboy wrote:"I have allways used regulair oli in my K75, K100 and K1100. It is better to change the cheaper regular oil more often, instead of using expensive synthetic oil."

That may be your opinion but is the complete opposite to mine. Better to use modern synthetic oil to save engine wear and to protect your engine should it get too hot for some reason.
Why save a bit of money on old fashioned oil when you would not do the same and buy cheap old fashioned tyres?

Regular oil old fashioned??? Bull***

Once again in your opinion.
BMW and Mercedes and most German car manufacturers only recommend synthetic oil for their modern cars.

Both of you are correct, but the Syn oil does not break down in high temps as much as Dino oil.  Given the temps of our K bikes I would think Syn oil would be better, and price is very small diff, if you shop around.  You don't need HD Syn 3 oil at $11.95 per QT in a K bike, Mobil One is good and cheap on sale.

bikerboy wrote:
BMW and Mercedes and most German car manufacturers only recommend synthetic oil for their modern cars.

True, but we are talking about a 29 year old bike.
What i meant is that after 12 yaers of storage it is wise to change oil frequently to get rid of the sludge and dirt in the engine.
For that you can use cheaper oil.
And indeed, just my two cents.... :smoke:

Not sure about prices in the US, but here in France I pay around €20 for 5 litres of 5W40 fully synthetic petrol oil and the K, the wife's F800 and my aircraft love it! The car is a diesel so gets diesel oil which is a 5W30 but also fully synthetic.
When you compare modern cars and old bikes, think back to the basics, the oil keeps two bits of metal apart. The metal does not know how old it is, nor does the oil.

One of the major causes of engine wear is cold starts.  Synthetic oil is better for that, especially at colder temperatures.

I can get a gallon of Shell Rotella T6 for $20 at Walmart. The non-synth Rotella is $13.  If I were running the non-synth stuff I'd change it every 6000 miles whereas with synthetic I change it at 10000 miles so pricewise for oil it's a wash but costs roughly half as much for new filters and makes it so I have to change my oil half as often and dispose of half as much used oil. (I keep it in a 3 gallon bucket and recycle it at the auto parts store when the bucket fills up.)

That said, K bike engines are pretty bulletproof so in the end it probably doesn't matter what kind of oil you use as long as you change it (and the filter) at regular intervals.

I agree on doing the engine flush (at idle) for five or ten minutes before changing the oil.

duck wrote:
That said, K bike engines are pretty bulletproof so in the end it probably doesn't matter what kind of oil you use as long as you change it (and the filter) at regular intervals.

I agree on doing the engine flush (at idle) for five or ten minutes before changing the oil.

Amen.

And I would agree with you there, Duck. The number of starts is a much more accurate measurement of engine life than miles/kms run. The thing is that after an engine start there is a period when the oil pump has not yet got oil to all parts of an engine. That time with no oil could be as much as 30 seconds - 500 revs without oil!
That is another reason for using synthetic, the viscosity range is normally wider. A 5W40 oil should, in theory, take a quarter of the time to get to all parts of the engine that a 20w40 or 20w50 would. Don't forget that it is only the first number that you are looking at for cold starts.

As the OP is more worried about old deposits in the engine rather than breaking in (Which was done when new), it would be better to remove the whole oil sump rather than just the filter when draining the old oil out. That was what I did with mine when I restored it. It takes about 30 minutes to remove, clean and refit the sump. He will then know that there is nothing much left in the engine that should not be there when filling with new oil.

bikerboy wrote:As the OP is more worried about old deposits in the engine rather than breaking in (Which was done when new), it would be better to remove the whole oil sump rather than just the filter when draining the old oil out.

And, don't be like me. Seal it with the black gasket sealant (medium heat range) or you'll end up doing it again in a year when it begins to leak.  

AJ.Valente wrote:

bikerboy wrote:As the OP is more worried about old deposits in the engine rather than breaking in (Which was done when new), it would be better to remove the whole oil sump rather than just the filter when draining the old oil out.

And, don't be like me. Seal it with the black gasket sealant (medium heat range) or you'll end up doing it again in a year when it begins to leak.  

And be careful not to strip the threads.

Hi there, regarding the oil I think that the better oil is the one you can easily access at a reasonable cost and is changed,  with the oil filter, at the proper mileage. For some is  synthetic for others a semi or a mineral. But our engines are at the 25 years stage and so are the seals, and the old seals dont get well with synthetics. My gear box started to leak when changed to synthetic and ceased when returned to mineral. Is not that synthetics cant be used on old engines is that old seals tend to fail more with the synthetics. If you rebuilt the engine and change all the seals, synthetic oils use to be the best solution for both performance an cost.
Hope this helps
Best regards
JAP

Leaking seals due to an oil being synthetic is another story that goes around. If you have seals that leak then they will leak. The seals do not know how the oil was made!
The way to get around leaking seals is to put sawdust in the oil   or use thicker oil. Early synthetics were thinner than the mineral oils around then (5W40 compared with 20W50) so that was the reason that there could be a slight leak on a worn out seal.

Hi there, its no story is a fact, depends on the state of your seals, working surfaces and the properties of the oil and you have to find if its your case  by trial, as I did.
For the sawdust you have to be sure is compatible with the synth oil.
Best regards and happy new year
JAP

The way I look at it is that there must be some truth behind the synthetic oil making worn seals spring leaks because there are so many people who say it has happened to them.

Rick, read my post. It is not the type of oil, but thinner oil. Try putting mineral sewing machine oil in and the seals will leak as it is thinner but not synthetic.
If you put 5W50 synthetic or 20W50 mineral in then the seals will not leak as it is the same thickness for most of the time.

You needn't worry about "breaking in" your 20 year old motor even if it has been sitting for years.  It was done thousands of miles ago before you bought it.  If you're going to flush the system, use the correct weight of any type of good quality motor oil, and a good dose of Techron or Seafoam.  Take that bad boy for a couple hundred mile ride and change the oil and filter.  Refill with the correct weight of any type of good quality motor oil, Synthetic or Dino and maybe add something like Guard Dog Moly.  I'd change the oil again  after +3000 miles.  

Your bigger worry should be the gearbox as the upper output shaft with its bushings and bearings goes dry from sitting for years because it's above the fluid level and is only lubricated by the transfer of lubrication and splash from lower shaft .  Not lubing that before reawakening your ride gets expensive.  I'd suggest you change the gearbox and final drive fluids with fresh and add Guard Dog Moly or the like at the same time you do the Techron/ Seafoam and immeadiatly proceeding teh oil change go for a couple hundred mile ride. 


Depending how it was stored, it may be smart to send the injectors out to be cleaned rather than just using injector cleaner in the fuel.

Wheel, triple tree and swing arm bearings may need replacing too. as the race may hav corroded or dimpled from sitting.  (mine had)

How is the brake fluid?  DOT 4 still will gum up so maybe flush and refill both front and back brakes before your ride.