Three bond or Yamaha bond from a bike shop far superior to normal RTV silicons and for the cork sump gaskets what I use successfully on Jaguar Engines is no sealant but torque the sump bolts and use loctite on the bolts so they maintain correct torque, That never leaks which is rare on Jag engines.
Most oil leaks from cork gaskets are because over time the bolts do not maintain correct torque the heat cycles allow them to back off over time hence the loctite fixes that issue.

On paper gaskets I have also successfully used a coating of Moly grease (CV grease) yes it is messy first time it gets hot but what is does is leave a coating of graphite on the gasket filling any small voids it when removed looks like a dry graphite coating and the gaskets come off with no damage.

First used that on Kawasaki Cam Cover gaskets so they could be reused up to five times before a new one was required, Later Kawasaki Cam cover gaskets came with a Graphite impregnation standard so I was duplicating what the factory did themselves.

I always used permatex non hardening sealant on paper gaskets, I believe it's a locktite product now, aviation non hardening sealant. Handy especially on water galleries etc where there is a chance of previous leakage and therefore pitting. This stuff stays tacky. I also use Stag on welch plugs too.
Ideally you should not have to use anything, however on old bits I usually do. Beats using half a tube of ultra blue on everything.
JD

Agreed, paper gaskets work fine without sealant. Never had a leak. As lamb-d says so long as the old gaskets are completely removed. RTV causes the biggest messes, only use it if no gasket is used, and only use the smallest amount. Nissan uses it on newer engines, but you gotta be careful with it

Yes, cork gasket is fine as long as the oil pan isn't over-tightened. Take some time to straighten the oil pan before installing it

Nulon L90 looks OK to me as a substitute for lithium grease

Personally I'm not a fan of RTV silicone in addition to gaskets. I recently rebuilt my A15 and didn't use any sealant on the sump. Cleaned heaps of it off from the last work done though. It was all over the oil inlet screen.

No leaks that I can see. The rubber seals that go over the main oils seals bedded in fine. The cork gasket you just need to get the tension on nice and even and be careful not to over tighten. It's easy to extrude it and ruin the seal.

I was a little unsure about the paper gaskets since they're so thin, I used a small amount of form-a-gasket, a liquid sealant on them. The only problem I had was the oil pump leaking because I didn't get all the old gasket off properly the first time.

I generally use plain old engine oil for assembly lubricant. I try to work on the principal only add stuff if you have to.

I've got some nulon L90 high pressure grease. It's used as an assembly grease, I guess I could use that on the seals?

Lithium grease is for extreme pressure. You can use other lube (like plain engine oil) but lithium grease is best. It's the same stuff used for disc wheel bearings

So lithium grease like the FSM says or any other lube ok?

I would use a very thin smear of a gasket sealant like permatex ultra grey or blue on all the paper gaskets just to be sure. Don't forget to lube all the seals ( the inside only )

perfect thanks

* For the rear main cap, use RTV sealant
* The paper gaskets are all that is needed (no sealant)
* Put the Crankshaft Seal in after assembling the crank & main caps, and checking the crank end play
* Welch Plugs and block breather pipe need zero sealant
* Any brand of assembly lube is OK. For a new cam & lifters be sure to use a product rated for camshaft