It could be the crank seals leaking, as far as I know we haven't found a source for the original style ones, but they can be replaced with O-rings of the appropriate size (there are two different sizes of the crankshafts & bearings depending on the age of the engine).
The first two engines I worked on ran OK with leaky exhaust collector gaskets (I had no replacements at the time), but I now replace them as they usually leak after removing the cylinder.
I think I have at least one earlier engine that refuses to run properly despite being completely stripped and rebuilt.
Hi guys, Thanks so much for this thread. An old gent asked me if I would get his tiny Tiger 300 running for him, and when I opened the carb, those little bits were rolling around in there. I'm lucky I didn't lose any of them. There's no way I could have figured this out on my own.
Best,
SparkFireRun got a reaction from factory in O & R Carb Repair Tutorial