Synythetic or regular oil

[flongr65]

I'm curious if switching to a full synthetic oil would be recommended. Have 23,000 miles on my 81 R 65.

[Bob_Roller]

A dreaded oil thread !!!

Just for informational purposes the moderator has stated that oil and tire threads should go into the Off Topic Discussions and Rant Section.

I'm sure he'll be by and move it again !!!!!!!!

My experience with oils is ,I was using Spectro Golden oil since around 1985 or 86, I'm not sure.

I never had a problem with it.

I moved to Phoenix from Chicago in 1993, and found that my R65 ran real hot in the summer temps of above 105 F. for about 5-6 months .

I saw Mobil One motorcycle oil, I've been using Mobil One in  4 wheelers since 1982.

So I thought the extra protection of a full synthetic would be a good thing.

I put the Mobil One in the R65 in November of 1999, January 2000, I started getting oil leakage from the rear main seal.

It got progressively worse to the point that within 4 weeks, that I had to do something about it.

So I replaced the rear main seal, leak fixed !!

Three weeks later the oil leak comes back again.

I was told to get the Mobil One oil out of the bike and go back to Spectro Golden.

I changed the oil, took the bike for a 300 mile ride, and the leak went away.

Other people have had better experiences with synthetic oil than I have, so I guess it's up to you on which way to go.

Justin's going to whack this thread but good, I can feel it coming !!!!!      [smiley=behead.gif]

[NC Steve]

Castrol GTX 20W-50, or similar (Valvoline, Kendall) high quality dino oil.
Now let me scoot before "The Boss" catches us...

[Semper Gumby]

WOOHOO another ADOT!

Currently I am breaking in the top end valve job with BMW 20W50 dino (*made for BMW by Spectrol).  After this next oil change I will go back to the Spectrol Golden 20W50.  

Yes Mobile One is Great Stuff ****  BUT **** If I had a brand new bike with brand new seals after break in Then and only then would I switch to Mobile One.  The Molecules are smaller and all the same size so if there is the slightest imperfection in any seal those little molecules get lined up shoulder to shoulder and march out.  

BTW - Spectrol uses Mobile Oil as a base and adds additives so I guess what goes around comes around.

(airhead deploys protective shield......)   [smiley=vrolijk_1.gif]

[flongr65]

Thanks for the input........I'm staying with the 15-50 Castrol

[dewjantim]

I like 20w50 mobil one synthetic car oil for my BMWs. Change it once per year and have had no problems.......Dew.

[Bob_Roller]

I think I just found out why I had problems with the Mobil One oil in my R65.

The 'cap' that goes over the back of the crank shaft has a small area of 'wear' right where the rear main seal rides.

When I was ordering my clutch parts yesterday, I asked about it, because the oil leak came back after I had put Castrol 10w30 in the bike last year when I was trying to figure out the hard starting problem that I had.

The owner of the shop said that the rear main seal has been upgraded, and has a teflon material instead of the spring to put pressure on the contact area of the seal.

Supposedly the upgraded part puts more pressure on the metal mating surface it rides on.

That has eliminated the leaking at the rear main seal.

Time will tell  !!

I'll post the differences between the seals next week when I get the parts.

[nhmaf]

OK, I'll contribute to yet another oil thread and say that I use "good old fashioned dino juice" in my my good old fashioned motorcycle.   My preference is for Castrol 10W-40 or sometimes 20W-50 if it happens to be in the middle of summer.   I've had very good luck with Castrol in all my motorcycles, and it is usually easy to find.  Now, for our 2007 Mazda, that takes some watery 5W-10 or some such oil, I can see where there might be benefits of slippery synthetics, or possible need for them...

All this said, I have been known to use synthetics in gearboxes and in final drives in motorcycles, but this little airhead seems to do OK so far with the regular dino-grade
stuff in the box thus far.

[tagordon]

My 2 cents worth:
I researched & found that the most endearing quality of synth' oil, at least IMHO, is the vapor/out gas / burn off is very low as compared to organic oil. So less topping off the level between changes.
The molecular structure definitely allows synth' oil to find openings, which to escape from. I ran some through to flush out my engine when I changed fluids right after I bought the bike. It showed me where I needed to concentrate my efforts. I have no leaks now, that I know of. BMW & Spectro Synthetic are now my primary choices. And as I have stated earlier, I use Marvel Mystery Oil as additive. Which makes my synth' "Blended". It lowers viscosity, so I use sparingly (4 oz) when weather is hot. In closing I want to say that untill SAE most recent Oil Grade Spec published I used Castrol GTX in everything. Now I use application specific lubricants as SAE Grades are significatly different.

BTW - Project at work, researching specs: power steering fluid vs transmission fluid.
Labeling & packaging seems to be only difference. But power steering fluid is 4-5 time higher in price per quart. I am sure there's a very logical & reasonalbe explaination.

[larstorders]

Years ago, I gave a hard life to 3 consecutive boxers  
The first two lived on dinosaur oil, 20 w 50 (duckhams Q) as reccomended for the local climate. At around 65K bores and valves were badly worn on both (genuine mileage on one, at least). The third boxer lived on synthetic 5 w 40 (Mobil 1). I was very interested to see if synthetic was worth the cost, so before selling the third at 50K, I pulled the heads to examine the wear. The bores were fantastic, lovely all round matt with even honing marks, couldnt be better and the valves were great too.
Were I a politician, representing government or trying to con you in some other way, I'd leave the story there. But there is of course more to it all.
The third boxer was an 81 R65 with Nikasil bores. The first two R80 and R100RS, iron bores. Like all good experiments there's comparability to be considered. The R65 had to work harder with the early morning motorway runs and slightly slower day time ones and the two up European touring . All bikes had the same mix of work and 5K oil changes.
Just a bit more evidence for the debate  :-/.

Synthetic sump oil always feels more slippery between the fingers than dino, I think.
I'm currently using dino on a short term ownership R65 which isn't used daily. Next airhead will be a Nikasil bore R100   and I'll run it on synthetic.

[Justin B.]

I have used the 15w50 Mobil 1 for a number of years in engines that still had good enough seals to handle it.  I currently have it in my wife's 1984 R65 and my 1981 R100.  I ran it in my '95 R100 up until about 50k miles when it then started seeping about the drain tubes and cylinder base.  Switching back to Dino caused the seeping to quit.  I guess the '81 is OK since I have had the cylinders off a couple years ago and all of those components have new seals...  I basically run the synthetic for an entire season (probably 7k-8k miles) and filter at every other change.  The synthetic is barely starting to discolor at change time.

Although NikaSil cylinders look brand new for like forever I have seen tear-down pictures of conventional automotive engines with a lot of synthetic miles on them that still had hone marks visible - and no ridge!

[larstorders]

DOH!  I said I used 5w40 mobil 1 in the boxers. I think my memory letting me down here because they didn't make one. Justin's post reminds me 15w 50 synthetic mobil 1 was available. Now I can't remember exactly what spec I used, except Mobil 1 synthetic and back then it would probably have been 15w50. Sorry folks   .
 I might use Comma 5 w 40 synthetic in the next one.

[tagordon]

Justin states:

currently have it in my wife's 1964 R65

I've been wondering about the 1964 R65.(?)
Sometimes fingers go...

[thrang]

I run mine on the cheepest 'normal' oil I can find and change it regulary, the 2 valve engine was not designed to run on anything fancy and I cannot see the point of expensive oil.

[Justin B.]

Oops!  1984...