Suzuki 6hp 2 stroke

[billows]

I have an ancient one of these bought recently.It must be as no kill cord.
It starts and runs fine when cold.
When hot it sometimes cuts on low running and is difficult to restart.It runs for a brief period and stops.Leave it for a bit and runs ok again.
It once reved up of its own accord and stopped much to my amazement.
What is the diagnosis?

[willk]

Maybe the wrong type of 2 stroke oil or the wrong mixture ratio. It sounds like it's on the verge of seizing. Of course, if it's running OK at higher revs, then it's not that.

[billows]

I use 50:1 mixture and proper 2 stroke oil for outboards.It is pumping water through the telltale and exhaust fine too.