[Richard230]

My 2009 865 EFI Triumph Bonneville also used shoulder bolts to secure the cover, but those bolts screwed directly into line bored camshaft caps     
Definitely something you don't want to strip.

I used to own a 2006 Suzuki SV650 and it had the same arrangement, as I found out when I over-tightened and stripped one of the cam cover bolts because one of the bolts was too close to a frame tube and I couldn't get my torque wrench over the bolt.  That was repaired permanently with a Timesert thread repair.  I also have a 2005 Triumph Bonneville T100 and I will have to watch out for that little issue too.  Thanks for the reminder.

[Subbu-500]

Just how serious or harmful is this slow oil leak from the head? I have noticed this on my 2014 B5 almost since new. I even remember the service center replacing either the head gasket or the rocket cover bolt O ring a couple of times. It is only good for a month or so and there is a leak soon after. But i never though much of it. However,  I did a 375 mile round trip this past weekend and noticed fresh oil leak from the head after riding at highway speeds (60/62mph) for a little over an hour. Though the gears felt a lot harder at the end of the ride, (especially the first and second) the engine felt no different. The next oil service is not due for another 3000 kms. so can i safely use the motorcycle till then? Or should i get the oil seal/O rings replaced now?

[Richard230]

Just how serious or harmful is this slow oil leak from the head? I have noticed this on my 2014 B5 almost since new. I even remember the service center replacing either the head gasket or the rocket cover bolt O ring a couple of times. It is only good for a month or so and there is a leak soon after. But i never though much of it. However,  I did a 375 mile round trip this past weekend and noticed fresh oil leak from the head after riding at highway speeds (60/62mph) for a little over an hour. Though the gears felt a lot harder at the end of the ride, (especially the first and second) the engine felt no different. The next oil service is not due for another 3000 kms. so can i safely use the motorcycle till then? Or should i get the oil seal/O rings replaced now?

Many years ago I owned motorcycles that would leak oil from their valve covers.  Any leakage that would make a noticeable decrease in your engine's oil capacity would cover the engine, and maybe your tire too, with an oil film and ruin your riding pants.  I wouldn't worry about it.  My guess is that the area where the leak is happening wasn't machined quite right at the factory.  You can try cleaning the area thoroughly and smearing some RTV silicone sealant around the location of the leak. (When you want to make a more permanent repair you can just pull the goo off using your fingernails and a sharpened wooden ice cream bar stick.) That stopped a leak on my 1971 Triumph Bonneville's rocker cover, even when it was just applied on the outside of where the rocker shafts poked through the valve cover.

[Subbu-500]

Thank you Richard. Glad to know i have not been ignoring something serious. I will just clean up the mess for now and get the O rings replaced soon just for the piece of mind.

[Blairio]

As you can see in the picture, I have an oil leak. I have ordered all of the replacement gaskets I think I might need, but am looking for your input as to what else may be causing the issue.

It seems there is a shadow of whatever is leaking directly above the exhaust. If it was the rocker bolt, why would this be?

Is the stuff on the cylinder head fins actually oily?  Or is it possibly the exhaust gasket that has let go and what you are seeing is soot & carbon?

[Arizoni]

IMO, the leak is due to the valve cover seal.

This seal is a plastic plate with a rubber seal molded into it.  The rubber is on both sides of the plate and over time it seems to lose some of its resiliency or, it "takes on a set" so it doesn't seal well.  This will cause the minor oil seepage that's being shown in the photos.
( I speak from experience because the seal did the same thing on my 2011, G5.)

I wouldn't bother to buy new seal plates because fixing the problem is easy if you have a good oil resistant gasket making compound.

Fixing it is not hard to do but it does require removing the fuel tank.

The screws that hold the rocker arm cover in place are socket head, shoulder screws.
The hex is fairly large so you might need to buy a Allen wrench to fit it.

Under each screw head is another plastic/rubber seal that is probably also slightly leaking oil.

Because the screws are "shoulder screws", they have a body that is larger than the thread with a square cut shoulder just above the place where the threads end.  This shoulder bottoms out on the cylinder head so trying to tighten the screws won't make them tighter.  About all that further tightening will do is to strip out the threads in the cylinder head.

That said, to fix the seal plate(s), get a tube of a silicon type, oil resistant, gasket compound like Permatex Ultra-Black.
Remove the valve cover screws and the valve covers along with the gasket seal plates. (including the round ones under the heads of the retaining screws.)

Clean all of the surfaces with some type of oil remover.  Disk Brake cleaner or denatured alcohol works well.

Make sure all of the mating surfaces are absolutely clean.  Then apply a very light coating of the sealing compound to both sides of the seal plates, the bolt seals and the mating metal surfaces.  It doesn't take a lot of the sealant but it should not have any uncoated areas on the metal parts.

Reassemble everything and tighten the bolts with just a moderate amount of torque.
(As I said, over tightening these bolts won't make anything except the screw threads tighter and it can do a LOT of damage.)

I did this repair to my G5 about 5 years ago and I noticed that somewhere under the valve covers there is a small seepage just beginning to work its way down onto the cylinder fin.  I guess I'll add fixing this to my "maybe tomorrow" list of things to do.

[hpwaco]

Arizoni,  great info on the rocker box plate seals and bolt seals.  Can't tell from looking in the parts manual how they are made.   Bolt seals on my 14gt are all cracked.  Not sure why RE used 2 different types/pn's.    Thanks, hp