65 Monza vents sporadically

[Davescycles72]

A gentleman I know,is working on his 65 250 Monza he bought new. He called me and said he can crank it once, and has to remove the plug to crank it again. It has the correct 1/2” spark plug, no sign of piston contact, the valves are adjusted correctly,
The engine kicks over fine without plug in, so the kick start gear is not binding. Now get this, the vent tube only expels engine pressure sporadically?

[Duccout]

Valve timing out?

[Davescycles72]

No engine turns over fine with plug removed, no valve contact on piston. And timing marks are correct. And ignition points just open at tdc, 8 degrees BTDC on compression. Must be something inside crankcase blocking air flow is all I can figure

[Duccout]

Just a thought: the spark plug is not contacting the piston is it? Possibly a long-nosed plug?

[Davescycles72]

Thanks for the reply that was my first thought also. Plug is a new B7HS. Update the man drained the oil which was the color of crude, though it has never run and the oil was new,along with filter. But more disturbing, was he found pieces of black plastic looked like old garbage bag. Apparently he has left stuff in the crank case, I might add he is 78. Also he is working on a shoe string budget. He said he found a piece about size of a dime. He removed the primary and clutch and rotor and stator to gain access.to bottom end.

[Duccout]

Damn, poor old devil (I know the feeling, I'm getting old myself). Sounds like another engine strip is called for.

Colin