Synthetic oil in a 78GS 1000

[Anonymous]

Hi all,

I have been running Castrol 10-40 in my engine.
I was thinking of trying the Amsoil 10-40 synthetic motorcycle oil.
At the dealer the counter salesman said that if I use the Amsoil, or any synthetic that you can never go back to regular oil. I asked him why, and what would happen if I did. He didnt know, and asked a few other guys
and I didnt really get any kind of convincing answer.
If anyone here knows for sure, I am curious as the reason why.
Do any of you use the Amsoil and would you recommend it for my bike?

Last year my mechanic put in a 20-50 weight and I was having some trouble starting the bike. He said it is probably a battery problem and the thicker oil would not make it harder to start. It would crank but not fire. If I did the old run and clutch pop, it would fire then be fine all day. After a few days of sitting it would have some trouble starting again. I thought the synthetic oil might help the problem but dont want to do it if it will cause more of a problem.

Thank you, Rich

[Poot]

well, as for the 20w50 weight oil being harder to start, the guy you talked to doesn't know what the heck hes talking about.

the 20, is the cold thickness of the oil. stock oil recommendation is 10w, so yes, 20w will make it harder to start, especially when cold. I would recommend 15w50 for the summer.



as for never being able to go back to regular dino oil, im not too sure. some rumors ive heard, is that after switching, damage might occur to the seals.


but, speaking from my experience, i have switched and seen no ill effects.




poot

[Keith Winter]

I have used Mobile 1 15w50 in my 1000 for 4 years and have never had any problems with anything. On really hot days it runs with less noise and better clutch action when stuck in stop and go traffic, with synthetic oil. I do know guy's that have switched back and forth from synthetic to dino oil, and have had nothing go wrong. Synthetic oil's strong point is it's ability to stand up to heat better and longer than dino oil. This is a major concern with our old air cooled engines.

[rodcwer]

The (you can never go back) remark is an old wives tale.I personally use mobil 1 15 w 50 it has worked great.I am not personally sold on the AMSOIL .I used it in my vehicles and used up more between oil changes than when I used MOBIL1.Also used both while racing Swamp buggies down here and found better over all performance with the MOBIL 1 over AMSOIL.The engine ran cooler and had less wear when on the mobil .
Mobil now makes a synthetic for motorcycles which is what I use now.
just my experiences so if there is AMSOIL LOVERS OUT THERE DON'T LAMBBASTE ME

[rodcwer]

Also synthetic oils do not break down like conventional oils.

[Gerry]

I found that when I switched to synthetic my clutch showed its age. It would slip when it was cold but once warm it would hook up. A friend has the same problem. I now run a Barnett clutch and no problem.

I also noticed that the tyranny shifts a lot easier and the motor runs a tad cooler with the synthetic.

I think the stuff is great 8) 8)

Been using it years

[redliner1973]

1st off, welcome. now for the answer......Amsoil 10w-40 and Amsoil 10w-40 M/C oil is ONE IN THE SAME. the ONLY difference is the M/C version has a pic of a bike on it----Seriously... BTW, where are you located?

You dealer is basically full of schitt---To an extent. You can go back to regular 'Dino' oil anytime after using a synthetic oil. At one time, many years ago, most all synthetics were primarily PolyAlphaOlefin, or PAO-based oils. the pao's had a tendency to shrink some rubber seals, and the natural detergent action also removed sludge causing a seal that was 'tight' from all the crud around it to weep or leak. Fuly synthetic oils nowadays have Esther-base oils added which counteracts this tendency, and does not cause this.
Amsoil, Royal Purple, Mobile One, and a small handful of others are true synthetic oils, not Hydrocracked Group III oils like Pennzoil, castrol, Valvoline (which, BTW, has the Weakest additive package of ANY Popular-branded oil), which are not really 'true' synthetics. This is one reason why they cannot be marketed as "100% Synthetic" outside North America. Amsoil and Mobile One's base oils are refined from the same Company, and are Identical. the additive package of each is different, however.
The 20w-50 oil you used should normally not cause a problem starting unless it was pretty cold. 20w-50 is actually a 20W base oil with Viscosity Improvers added to allow the oil to flow like a '50W' at 100 Degrees C. Most on the forum use either 10w-40, 15W-40 'Diesel' type oil, 15w-50, or 20w-50.
So yes, the Amsoil will work just fine, and when you need to change your oil, and you forget to order it from amsoil 3 weeks before, you can safely go back to a 'dino' oil without worry.

Hope that helps!

[Anonymous]

Motorcycle store employees pass on the same old-wives tales they were told. These guys are not a reliable source of info about oils.

Likewise, although Amsoil is likely as good a product as any, it does not have magical properties. I'm certain a cheaper alternative would be as good.

I run Mobil 1 15W-50 synthetic car oil most of the time. Sometimes I run Castrol GTX 10W-40 or 20W-50 conventional car oil if it'll be a short oil change interval.

[Anonymous]

You can't go back.

Another related saying "Once you go black, you never go back" has been scientifically investigated and proven true also.

[Pete Logan]

In the States, it is not a requirement to differentiate between full synthetic and semi-synthetic, as it is most other places.

This is what allows HD to sell its Syn3 as 'Synthetic' in the US, but it has to be marked 'Semi-Synthetic' here.

So there are three significant types of oil, dino, semi-syn and full syn.

This matters, because you can use semi-or full syn to top up dino, or each other. You can also use dino to top up semi-syn.

But you must not use dino to top up a full synthetic oil.

When doing a full oil change, it does not matter what you choose to use, or what you used previously.

As an example, my bike's PO is my next door neighbour. He ran the bike on 10W40 synthetic till it started burning oil, and then switched to 20W50 dino, which used less oil. I switched it from that to 10W60 Full Race Synthetic (Castrol RS). No problems.

My own view is that an oil change is the cheapest and best thing that you can do for your bike (or any other vehicle).

Therefore, I run the best Full Synthetic that money can buy. With my mileage, that costs me $40 a year, so who cares.

One exception. When I get a motor (regardless of what it is) that has been running dirty cos the PO neglected oil changes, I'll run top grade heavy duty diesel oil in it for a while. That often cleans it up without having to get in there. These oils have a lot more detergents in them. You can safely run them in anything.

Pete

[Anonymous]

Thanks for all the good info. I didnt think going back to regular oil would really damage anything but the point about the seals is probably the only thing that would cause a problem.
I will give the synthetics a try this time.
I may go with the Mobil 1 as its more readily available and probably cheaper.
The dealer wanted $10 a quart for the Amsoil. Still, thats not too bad for a whole riding season. I was hoping to see a rise in gas mileage too but I dont think that the oil will make that much difference.
I didnt know that Mobil 1 and the Amsoil were the only "true synthetics" and the rest were basically higher grade cracked oil.
Helping the bike run cooler was one of my concerns also.
I am located in Northeast end of New Jersey but I usually only ride in the warmer weather when its 55 degrees and above.

Thanks again, Rich

[Jethro]

Also synthetic oils do not break down like conventional oils.

Uh oh, I have to call foul...

That statement is in fact true, but a little misleading when we are talking bikes.

While Syn oil does maintain it's structure better in higher heat ranges, conventional dyno oils are not in any way compromised until above 550 degrees. If your engine sees those temps, it's become a boat anchor. At the temps we encounter in our engines, dyno oil is 100% as capable as syn oil, and does not suffer any more "break down" at any faster rate than the synthetic oils.

Now, if you are lucky enough to have a turbine engine powering your bike, please ensure you use syntetic oil!

Now keep in mind I am not at all bashing synthetics, they are fantastic oils. It just should be known the history of why synthetics were developed. They were designed for gas turbine engines because these engines do in fact see the temps that actually require a synthetic oil.

Whatever you use, change it at the recommended intervals.

[redliner1973]

[
Now, if you are lucky enough to have a turbine engine powering your bike, please ensure you use syntetic oil!

And why do you think that is? Most jet engines used to use mineral-based oils. they all use synthetic Because of it's higher threshold of temperature capacity before breakdown.

So yes, the mineral based oils DO break down faster than synthetics - this has been proven in thier molecular structure alone.

[KEITH KRAUSE]

Another related saying "Once you go black, you never go back" has been scientifically investigated and proven true also.

Yup! Black bikes are the best!

[Canada Dan]

I don't know the science of it, but I tried Amsoil in my '79 GS850 a couple of years ago.

I dropped the conventional oil, filled it up with the Amsoil product rode it a bit, drained it again and filled it up again with Amsoil (I thought it might be a good idea to get ALL of the conventional oil out).

Did the same with the transmission and the rear-end.

Again I don't know a lot about the stuff and maybe my clutch isn't perfect but almost immediatly it started shifting really hard - all the gears - all the time.

I went back to conventional oil within 1000 kilometers or so. After two or three services it started shifting like it used to, and has been fine ever since.

I did however leave the Amsoil in the transmission and rear-end and found that the rear-end runs much cooler than with conventional oil.

Dan.