Yamaha 6b power problem

[caroled]

2 stroke
In the water and in nuetral my engine ticks over nicely. At full revs it is fine also. In gear at full revs it stalls, but will push boat along at low revs.
Can anyone advise?

Also there is a plastic plug (inch and half diameter)half way up the shaft which is loose fitting; at full revs axhaust or some other gas is pumped from this vent. Any ideas?
Many thanks as you can see I am an beginner.

[boats.net]

Not familiar with that model but may need to rebild carbs. Some models had a rubber plug in mid housing to gain access to shift shaft coupling, if so may need to replace rubber plug.

[caroled]

Power Problem

Many thanks for that.
Could that loose plug have any effect on the running of the engine?