Re: added a tell tale and no water just vapor, also water trough spark plug, please r
It REALLY would be nice to know what engine you are talking about.
Like redfox said: it depends upon where you tapped for the pisser. If you took it from the top of the head---Believe it! You are not getting enough water there. If you tapped from the casting where the two holes are, then you will never get any water out the pisser.
Now, the leak from around the sparkplug is not a head gasket problem. Rather, the gasket between the head and head cover is leaking. The three or four small bolts next to the plugs hold the center and the head bolts hold the edges so to change that gasket you still need to remove the head. As a stopgap measure, you can try spreading some permatex in the edge of the hole but you must be careful to not get any on the plug seating surface or the threads so this is really not a good option.
As far as stalling, you must do the usual: check that all cylinders are getting spark, check that the plugs are not fouled, check compression ratio, and check idle speed.
The two exhaust holes in the back are just that: Idle relief vents and what they do is to keep backpressure low during idle or stopped conditions so the engine will not stall. When the engine leg fills with water--like from a wave-- they will go under and burble. This is not excessive exhaust or water pressure. They are operating exactly as they were designed.