Crusader 270 cuts out

[Carcare]

Hello, starboard engine starts and runs fine below 3000 rpm but when I run at 3400 rpm after 15 - 30 minutes sync gauge starts to jump to port then engine cuts out completely. Will not re start right away. It will restart after 30 minutes or so and run fine below 3000 rpm. 1984 270 that has been converted to electronic ignition ( petronix ignitor ) Seems like a heat issue but temp gauge never rises past 160. I changed fuel filters.

[bud37]

Check your anti siphon valve at the tank.....running with higher rpm at load would require more fuel, have a look at that side of it.......the other thing I might look at might be the sync gauge , could you try it with that disconnected...maybe heating issue with that. I am sure there will be some others but that is a start.......

[Carcare]

Thanks I will try that.

[Carcare]

Anybody know what would shut down engine at 3400 rpm. Ignition or fuel ? It takes 15 - 30 mins before she dies.

[mjk1040]

1984 Crusader's 350's. carbureted, are you open or closed cooling. assuming closed since u stated temp at 160 degrees. Weak fuel pump? Vapor lock? Have u checked the engine wire harness, is it secure and held together with a nylon wire tie so it can not come apart. Weak coil? Exchange coils to eliminate. Does it just cut right out or slowly quit? If it cuts right out, bam electric issue, if it slowly quits, fuel issue. The more I re-read ur post I'm thinking fuel issue. Did u cut the fuel filters apart and check for debris? Pick up screen in tank clogging? Fuel line collapsing internally shutting off fuel supply. Ethanol fuel may have effected fuel lines. since the issue only happens at 3400 rpms, seems fuel supply can not keep up with the increased fuel need. Keep us informed.