1988 Evinrude 60hp dies above 4000 rpm

So I can not get my 1988 E60tlccr to run more that a couple minutes above about 4k rpms before it just quits, very abrupt. But then starts right back up... It will run at 2-3k rpms no problem, but above there and it dies. I don't want to hurt the thing so I keep trying things in the fuel delivery realm. So far have rebuilt the carbs, cleaned the jets and orifices multiple times by both myself and Dave at Tuck's Marine here in Pinellas Park, FL. Additionally he boiled the carbs since the motor had been sitting before I bought it. I replaced all fuel line from tank to the racor(new filter too), to the pump, to the carbs, replaced fuel pump since the VRO was bypassed anyways, replaced primer bulb. I did a link and sync and timing, then the shop did too after he messed with carbs and installed the fuel pump.

What direction should I go next? I have a call into the shop but I know they are very busy with prime boating season. Dave said he did a good once over on everything else and that it seemed like a really clean motor other than the high rpm cutout. I am going to get a portable this afternoon and try running it off that. It is the single thing the shop did differently. But I had drained the tank after it sat and installed the racor fuel/water seperater to alleviate thos problems. Also the primer bulb does not go flat which seems to happen when there is a restriction from the tank?

Anything I'm missing???
Thanks!

Re: 1988 Evinrude 60hp dies above 4000 rpm

take an inductive timing light and study the strobe on each sparkplug wire individually as you reach your 4,000 rpm limit...possibly one or more aren't firing....include some fuel mix in a spray bottle on this trip and if the spark checks out...spray mix into each carb throat and determine if the rpm's pick up..if so, the fuel side needs attention...if both check out...a compression test is called for, as a matter of fact, it would be the first test I would do just to help eliminate possible mechanical problems...obviously you'll need a driver for the "on water" test

Re: 1988 Evinrude 60hp dies above 4000 rpm

See if you can get more RPMs by squeezing the primer bulb, this will tell you if it's a fuel delivery issue.