Starting having issues last week. First I got the check engine alarm, which indicates a fuel restriction.
Replaced the anti siphon valve with a straight through barb. Replaced the fuel filter (had to use in line type)and blew out the fuel lines which where replace in 2012.Started it up idle good for 10 Min or so. Then the no oil alarm light and alarm goes off. Before buying a new pump, I checked engine compression and all other obvious things it all checked out. Replaced VRO pump, took it out idles great jumps out the hole no alarms. But now it will only run wide open for about 30 seconds then starts surge. I can bring throttle back to 4K Rpm smooth's out run's great. I did that back and forth for over an hour yesterday.. Even soaked all carps with sea foam and new plugs... same thing.
Still sounds like a fuel/air problem but where is the question?
Any help would be appreciated...

Those plastic carbs can drive you crazy. They are touchy on the float settings. I would be suspicious of that or the 2012 fuel lines because I had some new fuel line, I installed about that same time, that I had to replace.

Thanks, Its only at high RPM, hard to duplicate in the shop. I used the ethanol resistant marine fuel line last time. I will change it and primer bulb see if that fixes it. Other than that I am perplexed..

I just replaced some of the same type of fuel line with the inner lining. It will begin to break down,at the higher rpm the fuel pump may be collapsing the weak spot in the line. That's what we figured on mine anyway.

Replaced everything no change still bogging down and surging at high RPM, idle, low rpms runs fine.
Pulled the cowling did notice a lot of gas coming from the carbs. Guess its time to find a good shop in the NTX area???