Synth vs dino

[bluewool]

I'll talk to Murray. Sea about that fresh air!

[Nessism]

This is false information. Be careful what you believe on the internet.

Double dog dare you to go to Bob Is The Oil Guy and start a thread proclaiming synthetic oil reduces friction and wear.

[Rob S.]

Let's get back to my original concern. Please look at the attached photo I snapped a few minutes ago. It is the front of the engine of my 1100EZ with almost 25k miles. As soon as I bought it, four months and 500 miles ago, I changed the oil and filter. I used Motul "3000 10w40". The previous owner said he used dino. I don't think he had the bike long and, although I don't consider him trustworthy, I don't think that's something he would lie about.

Question 1: Could someone please identify the area between exhausts 2 & 3 that is apparently seeping oil?

Question 2: Two inches directly above is another wet area. Is that the valve cover?

[Rob S.]

More seep

All other considerations aside (including the fact that I should, and will eventually fix the cause of the seeping), will a switch to synthetic now increase the oil seepage?

[koolaid_kid]

Yes, a switch might increase the seepage.
The top seepage is the valve cover gasket, an easy fix with an OEM only gasket.
The lower seepage is the head gasket, a more interesting one to replace. Have you checked the torque on that particular bolt?

[850 Combat]

I have used and currently am using several aftermarket valve covers and aftermarket half moons. No issues. I think I got one from Z1 for like 11 dollars a few years ago. I had a problem with a silicone Realgasket. It kept extruding. If it is a lot of work to get to, like a head or base gasket, I use OEM.

[1_v8_merc]

I won't run synthetic unless it calls for 5w20.

[tkent02]

The top leak is the valve cover, easy to fix.

The lower leak may or may not be the head gasket. I have seen oil from a leaky cam chain tensioner show up there. Hot oil swirling around can get most anywhere. It can go through the air passages between the cooling fins and end up there. Worth a check.

[JEEPRUSTY]

Oh and do night be zealous in tightening any bolts
You cannot fix a fully compressed gasket by over-tightening bolts.

You may end up stripping or breaking something.

[koolaid_kid]

I had two (2) aftermarket valve cover gaskets go brittle and break on me. Then the oil, which was supposed to stay inside, began to venture outside.
Since then, I use OEM. YMMV.

[Dogma]

" ...Synthetic base oils give enhanced performance because they are manufactured using advanced chemical processes, so their molecular structure and hence, their properties, can be closely controlled. For example, fully synthetic oils like Shell Helix Ultra are designed to flow more easily at start-up temperatures.."

http://www.shell.com/global/products...hetic-oil.html

The viscosity rating describes two points on a temperature vs viscosity curve. For similar chemistry oils, this curve should have the same shape. They've monkeyed with the chemistry enough to alter the shape of the curve to favor lower viscosity at temperatures below that where the first number of the rating is specified.

Still, this is not a unique feature of synthetics. Dino oil formulations are subject to similar manipulation, though maybe not to the same degree. So, if your gaskets are marginal, what you have to look out for is oils that claim to lower viscosity at low temperatures (Probably lower than you'd ride. Well, maybe not in Wisconsin.), where the higher viscosity will result in higher pressures in the passages. Also, if you think your gaskets are marginal, avoid higher RPM than you've used before, because that also results in higher oil pressure.

Honestly, if I'm worried that a bike may start leaking from such a small disturbance, I'd be looking at new gaskets. Worrying about mechanical issues is no way to enjoy a ride. Especially when the only seals exposed to full pressure are the oil gallery, oil pressure sensor o-ring, base gasket [o-rings], and head gasket. All the other seals are essentially exposed to just crankcase pressures from the pistons moving and maybe blow-by, or hydrostatic pressure in the case of the clutch and generator covers and a few shaft seals.

To my mind, the real reason to avoid synthetics in an old engine is that a tired old air-cooled engine is likely to be consuming oil, so you'll be burning, blowing or leaking more expensive oil.

[tkent02]

Still, this is not a unique feature of synthetics. Dino oil formulations are subject to similar manipulation, though maybe not to the same degree. So, if your gaskets are marginal, what you have to look out for is oils that claim to lower viscosity at low temperatures (Probably lower than you'd ride. Well, maybe not in Wisconsin.), where the higher viscosity will result in higher pressures in the passages. Also, if you think your gaskets are marginal, avoid higher RPM than you've used before, because that also results in higher oil pressure.

Most of the places where oil leaks from a GS engine are not pressurized.

Clutch and stator covers, cam chain tensioner, valve covers, tach drive, are common leakers and are not pressurized. A lot of the head and base gasket leaks are not from pressure either. It just seeps.

[bonanzadave]

The lower seepage is the head gasket

Would not be so sure about that. Looks like the two head nuts with the orings on them.

[Rob S.]

Dino

For the time being, I'm going to stay with dino.

And looks like I'll finally get to try my new, cheapo ($10) Pittsburgh Pro torque wrench. I think I'll practice with it on the rear axle nut, just to be safe.

I guess that's one of the reasons I like chain drive. Adjusting it is one of the things a non-mechanic like me can do, feel the difference immediately on a ride and feel good about it.

And thanks again for the package, Dave. I got my tach lit up with your help.

[Nessism]

Use your breaker bar, or a 1/2" ratchet to crack the head nuts loose before you try to make them up with the torque wrench. I broke my beautiful dial type torque wrench torquing the head on an 850. The nuts were really sticky and shocked the wrench breaking it. It's at the shop right now and going to cost $70 to fix the stupid thing. Maybe should have thrown it in the trash, but didn't have the heart.