Cause has developed slight piping ish sound.
 

Starboard engine has a slight poping. Not a carb popin more of a blup blup noise. That comes n goes out exhaust. Motor idles and seems to run fine. Leaking header. Cmi. Broken valve spring. , dam chit comes and Goes. No smoke. Just a blup blup blup sound. What's the gurus say 50 hrs or less on the clock.

I had a bad magnetic pickup in my MSD dist. that caused a weird miss/pop from 3500-4000. Swapped and no more issues.

What ignitions are you running? Sounds like possible crank or cam sensor?? Did you swap out ignitions yet. Seems like tinkerer on the board here among a few others had very similar problem. Do a search on tinkerers if you can. I might be wrong but sure seems like he pinned his down after much process of elimination. Also if I recall his was an intermittent type deal and not always consistent.

Thanks will start the process. Pulled al plugs n checked compression. All is fine there. So now to hunt for the ghost. Sorry bout the spell ck changed my wording. Hate that chit.

My crane boxes msd distributers

It spears a bad spark plug is the culprit. Yea. Easy fix. first fouled plug at 40 hrs. These motors are temperamental to fuel. Don't dare give them throttle during start up. Little squirt after they sit a week is all they want.

Awesome

Something isn't right. Sounds like carbs are dumping fuel.

Always something. During that run. I took off just breaking plane dam dog jumped up scared me so I got off throttles. Then notice she was tied up. So jumped back into it. All while going and coming off plane. I think that's when I fouled. Loaded the engine. But who knows. !