Crankcase clunk

[ecoflorida]

1991Tohatsu M50D has always been a "rattly" motor. Change plugs yesterday and noticed an intermittent "clunk clunk" in the crank case when cover is off. I emphasize intermittent. Not so much when cover on. Ran fine. Actually quite improved with Brisk Plugs. But, is something coming loose? Is some piece of something free in there?
Robert

 

[pvanv]

Seriously? How on Earth do you expect anyone to diagnose that symptom?

 

[robert graham]

Loose/warn wrist pin, warn crank bearings, piston slap caused by wear?.....could be lots of things....is it 2 or 4 stroke motor?....

 

[Sea Rider]

An earscope will sulrely diagnose that one, as long as NGK and Brisk plugs are rated and gaped exact same, how can Brisk plugs perform better. What has Brisk plugs that NGK doesn't have ?

Happy Boating