Timing has been verified as being correct, right? The ass-hats that worked on my 311 prior to purchase tried timing it without being in service mode. 35 degrees at idle. Dirty IAC and this timing issue caused it to surge (they claimed it was down on compression in four out of eight cylinders). I fixed the timing (and got the firing order correct on the other engine) and used it for another three seasons. Anyway, just an idea.

From what they told me it was set to factory. I would assume with the recommendations and well known of this shop they would know how to check it. But seeing as they dont know how to fix a low fuel pressure issue, maybe not.

https://cimg6.ibsrv.net/gimg/www.off...ee067a09b4.jpg
Well after dealing with my run ability issues all summer and a failed attempt at a repair shop to diagnose the issue we might have gotten somewhere. Just had the boat winterized last week and mentioned what it was running like and he said he would take a look. He said he first pulled plugs and they were all uniform in color but looked like they were years old. I bought this boat this spring, then he moved to the distributor and found the cap and rotor full of corrosion and the "advancer" frozen. He replaced plugs, wires and distributor and said boat ran flawless of course. But now its winterized so it'll be summer before we can actually test out. Still really disappointed I paid a marina $300 this summer to diagnose nothing and couldn't even look into the simple things like this. Lesson learned I suppose!

Yup cap is pretty bsd. The ‘advancer’ ? Lol. Must be miscommunication on this part right ? No such a thing. Your dist is all electronic. Module maybe ?

That cap is nasty!

One of the first things to change when taking ownership of a used boat before hitting the water.