thicker oil to stop small oil leakage?

[marp68]

After retorqueing all 8 big nuts to 30, the RHS back corner of the cylinder base is still sweating when driving. Doesn't leak when hot and idling. It's not really a big issue, but it's annoys me. An engine should not leak!

Have anyone experienced that a thicker oil have been a solution to similar problem? I'm thinking about changing from the motorcycle 15w/40 i'm using now to a 20w/50.

And would it be okej with a standard mineral 20w/50 oil, sold for cars and/or older worn engines? Where i nomrally buy the oil, they don't have it sepcifically for motorcycles.

Or what about just SAE 50 for older motorcycles, since I only use it during late spring and summer (15-30 degrees celsius)?

Thanks
M

 

[Speedthriller]

I always use 20w50 mineral oil from Bel-Ray. My manual says to use this. I don't know if it stops your engine from leaking

 

[Grinder]

I wouldn't use the car oil because it's probably not rated for wet clutch use. I get a little oil leaking from that same area once and awhile and I'm using 20w50. I've had a little success by cleaning the area real good and smearing some sealer along the joint and then wiping almost all of it off except right along the seam and leave it set overnight. Straight 50W I think would be way too thick on startup.

 

[Fleksta]

I switched to the Valvoline motorcycle 20w50 oil after noticing the same problem. It did help a bit but if I do a sustained high speed/rpm run it still weeps a little. Nowhere near as much as before though, just a light sheen visible in the gap.

Haven't retorqued the head bolts yet, but its on my "to-do" list.

 

[gggGary]

I am an oil heretic but you might try a fill of the automotive "high miles" car oil it is designed to swell seals, might stop a leak? I am part way through a fill of that stuff in my 180K miles Prius that is using a quart in 3500 miles, results are not in yet.

I have had several vehicles I brought back from long sleeps that had leaks stop just from frequent use again.

 

[NONclow]

Marp, since you only ride in fair weather you shouldn't need multi-viscosity oil. I run SAE 30W in the colder months, and 40W in the warmer months with great results.

Originally posted by Grinder
I wouldn't use the car oil because it's probably not rated for wet clutch use. I get a little oil leaking from that same area once and awhile and I'm using 20w50. I've had a little success by cleaning the area real good and smearing some sealer along the joint and then wiping almost all of it off except right along the seam and leave it set overnight. Straight 50W I think would be way too thick on startup.

I do recommend AGAINST partial or full synthetic oils. They have friction reducers that can cause clutch slipping.

I've had a little success by cleaning the area real good and smearing some sealer along the joint and then wiping almost all of it off except right along the seam

Sounds like trying to patch a tire from the outside!!

 

[NONclow]

BTW Marp, have you checked the base nut on the front oil feed line to the top of the head? Mine was a little loose after a rebuild and leaked a bit around base of cyls

 

[5twins]

10W30 and lighter car oils have anti-friction additives to make them more "energy efficient". These additives can make your clutch slip. 40W and thicker oils aren't helped by these additives (made more energy efficient) so they aren't added. 40 or 50W car oils are all I've ever used in any of my bikes. I've never used the special motorcycle oils. I've never worn a motor out or had one implode.

If you have not done so, you might try adding the power brake check valves to the ends of your breather hoses. These reduce crankcase pressure and can reduce, sometimes even stop, minor oil leaks.

 

[Grinder]

Synthetic oils are fine as long as they are motorcycle oil with the JASO MA2 rating for wet clutch operation. I use full synthetic in both of my bikes (Amsoil) Nonclow, ever heard of a tire plug?

 

[NONclow]

I said patch, not plug. Grinder ever hear of a tube?

 

[TwoManyXS1Bs]

+1 on 5Twins one-way check valves on breather tubes...

 

[Grinder]

Sure, ever hear of synthetic motorcycle oil? I realize the sealer is a band aid fix, but it did work for me and you don't even know it's there. Beats tearing the motor out and apart for a small leak.

 

[5twins]

Synthetic oil is so slippery that it's more prone to leaking out of old bikes with old seals and gaskets. Use it if you like but just be aware that you may start seeing some little leaks you didn't have before.

 

[Grinder]

Here is an interesting read on that subject.

http://bestsyntheticoil.com/info/seals.shtml

 

[neanderthal]

5twins has a good point. synthetic oil has a way of finding new places to run out of. in this case it may make things worse.

 

[neanderthal]

grinder do you realize how many probably, some's maybe's and mights there are in that. also it looks like amsoil put that out. in the fifties the cigarette companies told us it was not bad for us to take in that beautiful rich smoke. i dont maybe there is truth to that just saying dont believe everything you read. the bottom reads dont buy foreign oils...

 

[Grinder]

I think if your gaskets and seals are in good condition it shouldn't matter what kind of oil you use..it shouldn't leak. Most of us have 30-40 yr old seals though so it could be a concern. Personally I think the goods outweigh the bads for synthetic oil and will keep using it.

 

[xjwmx]

After I retorqued my head I noticed a small leak from the bottom of the cyl right over the stator but it went away after about 100 miles at highway rpms. Still not back after about 3000 miles.

 

[marp68]

Thanks for all feedback.

 

[XSLeo]

Another thing about synth oils is that the molocules thart make up the oil are all the same size and shape. Dino oils have molocules that vary in size and shape.
Some of these irregular shpes get lodged in the engine. This build up helps seal things a bit. The synth oil being smaller and evenly sized can get under these larger molocule build up and clean them out, often opening up passages from inside to out side that dino oils can't pass through.
On my Harley when I bought it it came with Dino oil from the factory. Took it back for the 1000 mile check up the changed to oil and used dino oil. I then ran it the reccomended interval. I changed to Amsoil 20w50 in all three holes, engine , primary and transmission. I was surprized that the oil got black very fast. Like in about 500 miles. As I kept using it at oil changes it got so it took longer before it got black. Now it takes aroun 1500 to 2000 miles before it gets much color. The black was the dino oil build up in the engine from just 5000 miles of running it.
In the primary the clutch wear colors the oil fairly quickly but in the transmission I go 10k miles and the oil looks like new.
After some expermenting I use Amsoils 20w50 in the engine, 10w40 in the primary, thier 75w140 oil in the tranny. 5k on the engine and primary, 10k on the tranny oil changes.
So don't let anyone say synth oils are bad for a clutch. Just look on the jug of oil, on the back it has a bunch of ratings, look for the JASO MA rating. That means the oil has been tested and approved for wet clutchs. This applies to dino as well as synth oils.
Leo