Dirty Inlet Z482

[Nauty]

I bought another Beta 10hp marine boat engine not running.

I connected it all up and sure enough it turns over , white smoke /vapour out the exhaust but not starting so I'm thinking compression must be bad.
I've removed the head and nothing strikingly bad but the inlet ports and valves are really sooted up and oily and I did notice some exhaust puffing out the inlet when I was turning it over and thinking it odd.
I don't think this engine has been stripped before so I imagine the timing is good and no damage to pistons/valves.

Anyone any ideas

To summarise ...Symptoms are

Cranks over nicely but wont start

Sooty/oily inlet manifold /ports and valve stems.

Could really bad injectors do this? Can't test them here unfortunately.

 

[North Idaho Wolfman]

Valve are not seating.
This could be from the valve lash not being set correctly or bad valves or seats.
I would start with adjusting the valves.

Bad Injectors would not cause this.

 

[Nauty]

I'll take a better look at the valves tomorrow but they looked perfect and lash was spot on.

Could it be head gasket? When I took the head off the gasket was in two pieces(layers) but no intermix so probably not that.

 

[North Idaho Wolfman]

I'll take a better look at the valves tomorrow but they looked perfect and lash was spot on.

Could it be head gasket? When I took the head off the gasket was in two pieces(layers) but no intermix so probably not that.

Some off these engines had a head gasket and a metal shim, so be mindfuul of that on replacement.
It wouulod be near to impossible for a headgasket to cause exaust out the intake port of the head.
A cracked head is another thing that could cause that to happen.

 

[Nauty]

Valve are not seating.
This could be from the valve lash not being set correctly or bad valves or seats.
I would start with adjusting the valves.

Bad Injectors would not cause this.

valves are covered in a sooty crust , looks like they’re not seated as the contact surface is black as well

this is an inlet valve