Tractor Repair: International 784, diesel injection, cylinder walls

Question
Big Dean,
I have a 1981 International 784 tractor with the D-246 diesel engine.  I have fuel leaking out around the injector where it fits into the cylinder head.  I pulled out the injector and put a new o-ring in.  It still leaks but i got to thinking that there should not be any fuel there anyhow because the engine should be burning it.  Could the injector be bad and providing too much fuel?  The engine starts real easy and runs smooth however my RPM gauge is eradic.  I am afraid to run the tractor because fuel could be washing down the cylinder walls and cause damage (is this a problem).  I appreciate very much any information you might be able to provide.  Thanks very much.

Ed Beddow

Answer
You have something leaking it could be where the injector screws together or the sealing washer on the bottom of the injector that seals the compression. I would take that injector to an diesel injection shop & have it checksd out. If the injecter was over fueling the cylinder you would have a big puff of black smoke out the exhaust every time it fired on that cylinder.