92b 351 pro boss 58 ho

having trouble after running a

having trouble after running at higher rpm the engine starts running rough until rpm are lowered to about 1500-2000 then runs like new read in the manual says eng. has a limp mode and this is what it does if ur having problem with temp or oil press. changed impeller t-stat blew all the water lines out new carb. fuel filter. the oil press. gauge reads good temp running about 160 but the problem still exsists any ideas what else to look for? thanks

check water in fuel

check water in fuel

"I have had a similar problem

"I have had a similar problem where it ran rough at speed but smooth at lower speeds.

It sure seemed like bad gas that accumulated over the layoff season, but wasn't.

The behavior with the limp mode is the way it is supposed to work - you probably have too much knocking at speed and the knock sensor is kicking in and the computer is taking you back down to below 2,500 rpms.

I replaced the spark plug wires with a new set.

It turned out one of the wires had excessive resistance.

It was really odd because I had put the boat away at the end of the season running perfectly and then the first day of the new season it didn't want to run good at speed. I tried many of the things you did - gas related, but it didn't solve it. On a long shot I replaced the spark plug wires and that did the trick.

I am still clueless on why/how the spark plug wires can go bad just sitting in the boat over the winter.

I am the original owner and now I automatically replace the plug wires every three years.

FYI, i have the same configuration - 92 ski nautique Open Bow with 351 pro boss engine.

FYI also see my post about the excessive oil pressure - any thoughts?"