High crankcase pressure

[Loucip]

I have a 1966 Honda 305 Scrambler that has not been run for a long time. Recently I got it running and realized that for some reason the crankcase pressure is high enough to force the oil from any way possible from the crankcase.

[conbs]

You might try searching this site. Make sure the gaskets/metal baffle are installed the right direction in the head cover. Also look at G-man's post under the "Piston Blowby" thread in this section.

[Hamamatsu Nippon]

One other thing to check is the oil level. Make sure it is not overfilled with oil, or more likely, has had gas leaked into the crankcase.

[mike in idaho]

You could try putting an automotive power brake check valve in the end of the breather hose, or one of these reed valves from Mike's XS: https://www.mikesxs.net/product/15-0677.html

[LOUD MOUSE]

Have you checked the comprehension?
You may have stuck rings. ........lm

I have a 1966 Honda 305 Scrambler that has not been run for a long time. Recently I got it running and realized that for some reason the crankcase pressure is high enough to force the oil from any way possible from the crankcase.