I just introduced myself a few minutes ago so I thought I should post this in a differnt catagory.Does anyone know a possible source for part# 93103 38086 00.Alas, I have high pressure at the oil cap hole while kicking over and no start with good spark and fuel present.

Check with Enduronut or DEET. 

If no luck with EN or DEET, there are some on fleabay.

A good quality bearing supplier might also have them - see attached link to a company in the UK. I would be interested in the experts' views on using an aftermarket part such as this.

Search Results: - Simply Bearings Ltd

Not common for the 360 to push the crank seal out but 'does' sound conclusive in your case. You could set the piston at the bottom & pressurize the trans breather tube & see if you can hear it down the plug hole. Or carb & reed block off & piston at top, that'd work & hear it via the inlet. I've never needed to do that but just clutching at random ideas.

"Not common for the 360 to push the crank seal out"

I was surprised when it happened on my DT360. Surprised because it actually bent the seal retainers!
 

Link to ebay seal

careful about buying transmission seals from buzzards that put these on eBay next to a Yamaha label

An event like SCHU in post #5 can happen if there's an explosion in the crankcase or even a belly full of fuel & a good kick. Or ignition crank key broken & timing then anywhere but right so fires up whats in the crankcase & seal escapes under pressure. Anyway--new seal & onwards & upwards. Hope the left one is still i place but right escaping probably saved the left side.

@Msavitt, I bought a set of gaskets for my 73 MX250 from Bike Buzzard. I have not opened the pack yet, and I have had them for a while now. I presume there may be an issue with what he sells?

Hackman101 - to be clear I was not referring to the person you mention, who I have bought from without issues.  I used buzzard as a pejorative - like bottom-feeder, scavenger, etc.