I have been having this problem for some time as I havent run the engine in a month or so. Last time I run it, I replaced the plug twice. Today, I put in another new plug. Problem is the same

I have also reset the LSN to 2.5turns out from closed as per the manual

Another thing, I hear a sucking sound when wiggling the prop... you know... a kisk-kisk. I don recollect this from before. Think its coming from the carb but not sure.

Any ideas what the problem is? I havent run at full throttle, running in the house so I cant check the top end

Ameyam