TOPIC:

Here are a couple of interesting AMSOIL links on the subject:

Converting to AMSOIL and Breaking in a New Engine

AMSOIL Break-In Oil (SAE 30)

That's some great info from Amsoil...here's one quote from the article, "Breaking in a new engine is the one area that petroleum oil is better for than synthetics. You see, petroleum oil has a very low film strength which is ideal for breaking in a new engine. That is why we recommend you run the factory installed petroleum oil for about the about the first 500 miles. Then drain the oil, remove the factory installed oil filter and then install AMSOIL Synthetic motor oil and an AMSOIL Super Duty oil filter and your ready to go".

I'd vary the rpm's, and on the highway, accellerate and close the throttle several times a mile, first building cylinder pressure, and then with the throttle closed, pulling oil past the rings. This method will "Scuff up" the various rotating and rubbing parts for optimum break in.

The oil change after break in is very important,as the engine has shed a majority of the sharp edged pieces on the machined parts, and needs new, fresh lubrication now.

79MKII wrote: I'm wondering if it depends on the type of synthetic oil you use for break in? Maybe the type available when it was relatively new was the extra slick type that would make our clutches slip...

The myth was born because most new oils have molybdendum disulphide (moly) in them and that ruins clutches. If the oil says "energy conserving" on the label, it has moly. Slick 50 also has moly. I have never seen any convincing evidence that syn oil causes rings not to seat or gaskets to leak. As somebody pointed out, some of the very expensive new cars come from the factory with syn oil in the engines.

wireman wrote: Well as many times as I change the oil after rebuilding a motor it would be really expensive/waste of money to use synthetic.
I change it after 30 minutes of running ,then again at 500 miles .

Me too, so I don't use syn on first run because it costs too much to run 50 miles and dump.

baldy110 wrote:

bountyhunter wrote: You can switch anytime, you can run syn from the start. It's a myth that engines won't break in using synthetic oil.

Is this from personal experience? My own experience from rebuilding engines is I have never managed to get the rings to seat using synthetic oils. I end up taking the top end apart re-honing the cylinders then reassemble and break in again with conventional oils. After about doing that 3 times on 3 different engines I no longer break in using synthetic oils. I have never had a problkem breaking in rings with conventional oils.
To answer the OP's original question, yes you can switch at 1200 miles. I usually wait until I have 1000 miles on a fresh engine then switch if I want to.

I base it on the fact that some high end new cars are running full syn from day one.

I use Lucas full synthetic motorcycle oil. They also have a partial synthetic if you are still on the fence about the break in period. I also use the fuel additive to keep the top end lubed. When the bikes came out we still had lead in gas which lubricated valves. It also keeps everything clean. I run Lucas in everything with a motor. Just my opinion.

kaw-a-holic wrote: I use Lucas full synthetic motorcycle oil. They also have a partial synthetic if you are still on the fence about the break in period. I also use the fuel additive to keep the top end lubed. When the bikes came out we still had lead in gas which lubricated valves. It also keeps everything clean. I run Lucas in everything with a motor. Just my opinion.

I have also been running the Lucas fuel add "top end" stuff for about five years. It keeps the gas fresh and keeps the carbs clean. I haven't had to do any maintenance on the carbs in that time. Good stuff.

www.amsoil.com/catalog.aspx?code=MCFQT-EA

I don't recommend a full synthetic oil, Use a semi/senthetic oil, and one made just for motor cycles. Full synthetic oil can cause your clutch to slip and burn out. Automotive oil doesn't have the molecule shear additive in it like motorcycle oils have, due to the transmissions running in the same oil as the engine oil. The gears shear the oil molecules very quickly if it is not motorcycle oil.

bountyhunter wrote:

baldy110 wrote:

bountyhunter wrote: You can switch anytime, you can run syn from the start. It's a myth that engines won't break in using synthetic oil.

Is this from personal experience? My own experience from rebuilding engines is I have never managed to get the rings to seat using synthetic oils. I end up taking the top end apart re-honing the cylinders then reassemble and break in again with conventional oils. After about doing that 3 times on 3 different engines I no longer break in using synthetic oils. I have never had a problkem breaking in rings with conventional oils.
To answer the OP's original question, yes you can switch at 1200 miles. I usually wait until I have 1000 miles on a fresh engine then switch if I want to.

I base it on the fact that some high end new cars are running full syn from day one.

Metallurgy and machining are much more advanced than 20 to 30 years ago too. I have owned a few new Triumph motorcycles. They were filled from the factory with convential oil for break in. Then at 500 miles they require a change to synthetic.

vintagebiker wrote: I don't recommend a full synthetic oil, Use a semi/senthetic oil, and one made just for motor cycles. Full synthetic oil can cause your clutch to slip and burn out. Automotive oil doesn't have the molecule shear additive in it like motorcycle oils have, due to the transmissions running in the same oil as the engine oil. The gears shear the oil molecules very quickly if it is not motorcycle oil.

This is not accurate. Using energy conserving automotive oil is said to cause clutch slippage.

I have run full syn in several wet clutch motorcycles (all done per the manufacturer's recommendations) with no problems. I would say almost all motorcycles made today the manufacturers recommend full syn; either wet or dry clutch.

vintagebiker wrote: I don't recommend a full synthetic oil, Use a semi/senthetic oil, and one made just for motor cycles. Full synthetic oil can cause your clutch to slip and burn out. Automotive oil doesn't have the molecule shear additive in it like motorcycle oils have, due to the transmissions running in the same oil as the engine oil. The gears shear the oil molecules very quickly if it is not motorcycle oil.

Sorry, but you need to do a little homework on full synthetic oils. Full synthetic MOTORCYCLE oils that meet the JASO-MA standards are perfect for our bikes because they are made specifically for wet clutch motorcycles. As far as the AUTOMOTIVE oils, I do not know of any currently produced synthetic, blend, or non-synthetic, oils that meet the JASO-MA standards, so I would not use them in a KZ.

For your homework assignment, please read the following link. Notice the description "Optimized wet-clutch performance - Meets JASO MA." All kidding aside, MOTORCYCLE synthetic oil works great.

www.mobiloil.com/USA-English/MotorOil/Oi...acing_4T_10W-40.aspx

For the record, it's generally not the oil which fails due to motorcycle usage, it's the additives specifically viscosity increasers (VI's) which are long polymer molecules. Running the oil through the gears in the tranny chops them up over time and your 10-40 oil gradually turns into 10W oil. Some of the better new oils have stronger VI's.

An advantage of pure synthetic oil is that it takes very little VI additive to make it track the multi grade viscosity profile, so it has less additives in it. In that regard, true syn is actually better suited for bike usage.

general oil info;

www.calsci.com/motorcycleinfo/Oils1.html

same reference as to why I doubt the "synthetic won't break in" :

Choosing a Break-In Oil for Your Motorcycle

The theory that synthetic oils should not be used during break in is the same as the theory that your engine will break in better if you use synthetic oil but add a dinner candle to your four quarts of engine oil. Frankly, I find this theory, um, questionable. Oh, hell, laughable. Corvettes and Porsches come from the factory with Mobil-1 in their engines. Remember, these engineers have designed world-champion engines for F1, Indy, Le Mans 24 hours, etc.

There's a lot of mythology surrounding break-in oil. It's simply not the case that synthetic oils are more "slippery" than conventional oils. Also, break-in of a modern engine is completely different than break-in of an engine made before about 1980. Modern engines, by comparison to something made in the '60s, are pretty much already broken in from the factory due to the fact that today we hold much tighter machining tolerances. The exception, of course, would be the Ural, a motorcycle made on a production line unmodified since about 1935.

bountyhunter wrote: For the record, it's generally not the oil which fails due to motorcycle usage, it's the additives specifically viscosity increasers (VI's) which are long polymer molecules. Running the oil through the gears in the tranny chops them up over time and your 10-40 oil gradually turns into 10W oil. Some of the better new oils have stronger VI's.

An advantage of pure synthetic oil is that it takes very little VI additive to make it track the multi grade viscosity profile, so it has less additives in it. In that regard, true syn is actually better suited for bike usage.

general oil info;

www.calsci.com/motorcycleinfo/Oils1.html

same reference as to why I doubt the "synthetic won't break in" :

Choosing a Break-In Oil for Your Motorcycle

The theory that synthetic oils should not be used during break in is the same as the theory that your engine will break in better if you use synthetic oil but add a dinner candle to your four quarts of engine oil. Frankly, I find this theory, um, questionable. Oh, hell, laughable. Corvettes and Porsches come from the factory with Mobil-1 in their engines. Remember, these engineers have designed world-champion engines for F1, Indy, Le Mans 24 hours, etc.

There's a lot of mythology surrounding break-in oil. It's simply not the case that synthetic oils are more "slippery" than conventional oils. Also, break-in of a modern engine is completely different than break-in of an engine made before about 1980. Modern engines, by comparison to something made in the '60s, are pretty much already broken in from the factory due to the fact that today we hold much tighter machining tolerances. The exception, of course, would be the Ural, a motorcycle made on a production line unmodified since about 1935.

I think my head just explo9ded!

bountyhunter wrote:

Choosing a Break-In Oil for Your Motorcycle

There's a lot of mythology surrounding break-in oil. It's simply not the case that synthetic oils are more "slippery" than conventional oils. Also, break-in of a modern engine is completely different than break-in of an engine made before about 1980. Modern engines, by comparison to something made in the '60s, are pretty much already broken in from the factory due to the fact that today we hold much tighter machining tolerances. The exception, of course, would be the Ural, a motorcycle made on a production line unmodified since about 1935.

This contradicts what you posted earlier about the OP using syn after a rebuild. The OP has a '79 MKII, which according to this quote should be treated differently than a modern engine.

The bottom line with oil is........there is no bottom line, only opinions and a mix bag of experiences Many of the bad experiences can be attributed to items 1 & 2 below.

Several things can and will affect the rings / cylinders:

1]hone grit
2]block preparation prior to assembly
3]ring material

MYTH: Spraying the bores out with carb cleaner or brake cleaner will get them properly clean for final assembly.

MYTH: dumping extra oil into the cylinders is a good idea on a fresh motor.

LarryC wrote: The bottom line with oil is........there is no bottom line, only opinions and a mix bag of experiences Many of the bad experiences can be attributed to items 1 & 2 below.

Several things can and will affect the rings / cylinders:

1]hone grit
2]block preparation prior to assembly
3]ring material

MYTH: Spraying the bores out with carb cleaner or brake cleaner will get them properly clean for final assembly.

MYTH: dumping extra oil into the cylinders is a good idea on a fresh motor.

Hey now wait a second oh wise master of all things cylinder head related!
I still spray bores down repeatedly with carb cleaner and scrub the hell out of them with white toilet paper repeatedly till I see no more black crud before assembling motors.
And yes I do get lots of crud out of fresh cylinder bores by doing it this way.
And I still install fresh pistons/rings dry in the bore without oil on them ,thats the way I learned to do things watching the older guys do things as a kid and its always served me well anyway.

pig9r wrote:

bountyhunter wrote:

Choosing a Break-In Oil for Your Motorcycle

There's a lot of mythology surrounding break-in oil. It's simply not the case that synthetic oils are more "slippery" than conventional oils. Also, break-in of a modern engine is completely different than break-in of an engine made before about 1980. Modern engines, by comparison to something made in the '60s, are pretty much already broken in from the factory due to the fact that today we hold much tighter machining tolerances. The exception, of course, would be the Ural, a motorcycle made on a production line unmodified since about 1935.

This contradicts what you posted earlier about the OP using syn after a rebuild. The OP has a '79 MKII, which according to this quote should be treated differently than a modern engine.

They were talking about engines machined/assembled back then,his motor is being rebuilt now.

I put conventional in for break in, because its too expensive to use syn for only 500 miles like others have said. I have semi syn to go in her after that. But thats only because i thought it was syn and just bought it. It's Motul 5100 bike oil. Should work fine. As long as you have 10W40 or similar, motorcycle oil, it will work for anything you want to do with it. All this debate is pointless. Go stick some oil in your bike. Synthetic will run cooler and last longer than conventional oil. I put it in because it wont break down as much in the heat. So I can go longer between changes. Everything else is moot really. Synthetic is only better because its more uniform and doesn't break down as easily.