Pjme go and buy the Athena engine gasket set. Cheap at 20 quid and you can ensure good quality. Even the head gaskets!

I always feel that would you really feel comfortable riding a bike flat out only having tested it with a warm.up warm down procedure.

There are other reasons why you should run an engine in. Piston ring and cylinder wall glazing can occur if you don't follow an appropriate run in procedure.

So what I mean is that a set of superfire plugs for my starlet is £100. Personally that isn't worth the money. A set of iridiums are £30.

A spark plug for a dt is what 6 quid. And iridium is 9 quid. So its not a lot of money. They are supposed to last longer but if your bike runs overly rich or lean then sure it will wear an iridium faster. But thats not a fault of the spark plug.

I don't swear by them. But I have always ran them. For no reason other than they cost more, so that must mean they are better. Poor logic for sure.

I have no experience with the pedmoto but they look good. If they're stainless steel then they should last longer than a dep which was my gribe with the dep.

As for the oil blanking. I would remove the oil pump. Oil cable and oil lines and tank. You need to gap the oil line from the inlet manifold to reed block as this will cause an air leak.

The other one is that there is a cog driven off the crank shaft that drives the oil pump. Although the oil pump is removed this cog will still turn. So remove the cog clutch cover to stop this cog for spinning. Freeing up 0.0000001% parastic loss from the engine. Every horse counts!

That's a point. Yeah at least if you remove the cog you could leave it all in tact. Choice is yours.

Thanks Calum!
Got it sorted out today. Ready to fit the engine again in the next few days, can't wait..

In a similar position myself, here's a exploded view of the internal components:

http://www.boats.net/parts/search/Yamaha/Motorcycle/1969/AS2C/OIL PUMP/parts.html

I had to stretch out the plunger spring as it lost some of its original force and wasn't returning down.

Replace the internal seals also. They are cheap from simplybearings.co.uk, just standard shaft lip seals, sizes are 4x9x3 and 14x25x5

p.s. always take photos as you disassemble stuff, for this exact reason!

Yes that's what I thought, but the stroke should still increase at any speed if the pulley is depressed? I'm sure I gave it enough time as it went up/down a few times?
I took the pump off the engine, and a load of oil ran out of the pump where worm gear shaft goes into the pump body. Is that normal? There is a gasket there, but is that worm gear cavity supposed to be full of 2T lube?

Just copy and paste the link mate.

Yeah, my advice would be to have a shield made that would shield it from the majority of exposure. Not uncommon practice for air filters.

As said I've never had an issur and I've ridden in all sorts.from sunny to torrential rain. But perhaps your situation may be more difficult.

Some photos might be handy here so we xan visualise the problem.

Yamaha do a ruthless two stroke race bred machine called the TZ. The TZ is a full Grand Prix bike. So presumably it runs some sketchy kind of little end bearing.

http://pages.ebay.com/motors/link/?nav=item.view&id=201394504785&alt=web

That's the rods I use. Very high quality. But PJME recommend Long rods for generic builds. Mines supposively tuned.