Hi Guys
My DT started an oil weep from the clutch cover so I ordered the gasket etc ready for a swop out. 10 weeks later I got the bike out to warm the oil ready for stripping out.
Amazingly the DT started first kick!!!, I thought great then when I looked behind me the whole street was engulfed in smoke... I quickly blasted down the rd with a big smoke trail behind me, 5 mins later it stopped puffing clouds out and I now assume the crank seal has been weeping over the ten days, so while the cover is off I need to change this.
is there a dedicated thread to this operation? if so would be good if someone can point it to me, or run me through the gotchas on this thread.
I was curious on how to lock off the idler pully to get the nut off and once off the manual is vague on seal orientation and other parts that need to be removed to get to the seal.
Any tips, pics and walk throughs appreciated
Cheers
Gary

It could be that your oil pump check valve isn't shutting off completely ,
due to deposits in the seating area .

Yes as Swoop says. It's in the union exiting the pump up to the cylinder. No18 & 19 inside 20. If ya using it more regularly probably be ok as it is. Doesn't take much to stop it sealing off.
www.partzilla.com/catalog/yamaha/motorcy...l-pump-250b-c-400b-c

As others have said, pumps seep.  I'd ride it and it probably won't smoke excessively unless parked a while again.  I've had bikes empty a full oil tank into the crankcase while parked for a year. 

Just keep an eye on transmission oil level and if it's not leaking and level drops, then you might have a crank seal problem.

Hi Guys
thanks for the advise, something I never thought of and will look at this as well as makes sense.

while the side is off I may as well carry on and fit the crank seal as have the oarts at home now and the 29mm socket ready, so any more advise appreciated on the removal and refit appreciated
regards
Gary
 

Also on the oul pump outlet, is this just a push fit or screwed in, a quick look at mine and it looks like an aluminium fitting

I have done the crank seal, was a bugger to get out, but prior to that the seal retainer screws were chewed and I had to chizel them to remove them, I did the drill and screw procedure which finally it gave up for removal. on re build 1 clutch basket bolt snapped or re tightening at 5 ft lbs, was like cheese hardly any pressure on the bolt so I suspect a weak bolt. 6 new ones on order.
I replaced the kick start seal and now ready to remove the oil pump and have a look at removing the pump pipe feed fitting. this is aluminium so I assume gripping it and twisting will release it? I dont want to snap it in the pump so any help here appreciated

Is there a torque spec of 5 ft-lbs on pressure plate screws?  Seems too tight to me.  Surprised all of them didn't break.  I just snug them down.  I read somewhere once that with a normal screwdriver maximum torque an average person can achieve is 2 to 3 ft-lbs.  I doubt I tighten them more than 1 ft-lb.  Just bottom out shoulder and then "snug".  I learned that years ago after breaking one off by cranking down on it. 

Why would you remove the pump feed fitting? 

Just my warped thoughts but i thought 400's would have 6mm bolts not 5 like early dt1's & thinking 5 ftlbs wouldn't break anything. [but you managed to]. I know i overtighten everything--do up till it strips then back it of a turn, that's me.

Hi Mark
i cannot find a torque setting for the bolts, so i assume the torque would be for a m6 standard bolt at 7 ft lbs.
the new bolts from yamaha dont have the screwdriver slot in them just a hex
the reason im taking the fitting off is as per above advise that they may be crud on the ball valve seat so i need to get to it unless there is another way to clean thi seat?