I've read up on Snowbum's site and all around advrider, but I can't find a definitive answer, so here goes: When assembling the cylinders back onto the block of a 1972 R50/5, I know there is a base gasket (aluminum) and that sealant (dreibond) should be used. But which surfaces get the dreibond applied to them: 1. base of cylinder 2. outer face of gasket 3. inner face of gasket 4. crankcase many thanks!
In my book it is a gasket or sealant, not both. So a base gasket, alu or paper, and an O-ring on both top studs. And a smear of grease on the pushrod tube rubbers to help them in. Paul.
There are no O-rings on /5 engines. In my oldest Chilton manual there isn't any mention of using any sealant of any type on /5 engines. In the past, I have assembled engines using a very thin smear of sealant between the base gasket and the engine block. If you do decide to use something, be very careful not to block the oil supply holes. Woodgrain
In the '70's, Hylomar was the sealant of choice according to BMW. Yamabond 3 worked like a charm for me. Don't forget, everyone has an opinion... woodgrain
I continue to use Hylomar with good results. Hylomar Blue is what you'd ask for. Use sparingly = thin film is all you need.
To answer your question, put your choice of gasket goop either on the crankcase or aluminum gasket face, and then either on the other side of the aluminum gasket or cylinder base. Basically between the crankcase, aluminum gasket, and cylinder base, there are two seams. Apply gasket goop to one face of each seam. Also, be sure to read the directions on the container about how to apply it, and, like woodgrain wrote, be extra careful not to apply so much that it clogs the two oil holes above the two upper studs. See the lower photos on this page: http://www.pbase.com/dqmohan/prtseals
I use this stuff; I have never seen anybody else mention this product for this application. I think it works great. There is almost no chance of over application or blocking the oil feed holes. Spray two thin coats on both sides of the base gasket and assemble. It goes on dry. Is less messy and not difficult to use.
Dreibond works well and in my experience on both base gasket and non base gasket bikes, results in a seal that that is absolutely dry, doesnt even mist oil. I would not get too paranoid about the rocker oil feeds, just check the oil flow after you have the engine back together, by turning over the engine on the starter, with the plugs out and grounded.
