Motorcycle Repair: spark plugs/ oil adjustment, yamaha rd350, middle groove

Question
Hi Michael,
I have a 1973 Yamaha RD350, and the spark plugs seem to get fouled too quickly.  I don't ride the bike at high speeds, and I do blip the throttle regularly.  It seems that the spark plugs are getting fouled too quickly.  Is there a way to adjust the oil flow to the plugs?  And is it fairly easy to change the oil?  I've looked at m/c repair books, and it seems to be straightforward.  I'm not sure where the drain plug is, though.  (I've been looking for a reasonably priced repair book.  I don't have the MOM.  Any suggestions as to where to find one?  I've been checking ebay.)
Thanks in advance for your help.
Val

Answer
Val,
  As far as the manual goes try  http://www.jcwhitney.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=1011...
OR http://www.motocarrera.com/ for a possible link to one.

As for the fouling problem you are having, this can be the result of many things, especially for a bike of this age.  Do not attempt to adjust the oil pump yet.  What you need to do is remove, clean, adjust and reinstall the carburetors.  I can't go into this at great length; you will need to follow the manual's instructions carefully.  If you are running the stock pipes make sure the main jets in the carbs are stock (no markings) and set the "e" clip at the 3rd or middle groove.  You now need to check your compression w/ a bike or auto compression gauge threaded for your plug's size.  You should be seeing at least 45 lbs.  If your compression is low you may need to rebuild the top end (rebore cylinders, refit w/ appropriate sized pistons and rings and reassemble w/ new base and head gaskets).  An engine suffering from low compression can foul plugs at the very least.  You must next attack assessing the points.  Again for this you'll need the manual.  I unfortunately don't have the time to fully explain the process. Study the books instructions slowly.  You may want to make the move to an aftermarket electronic ignition in the future, set it once and it's good indefinitely.
 You need to do these things first before looking to the oil pump, rarely do these models need adjustment.
 If you find yourself confused at any point while using the manual please don't hesitate to drop another line.

Hope this helps,
Mike