I have twin crusader 250s on my 28’ 1960 Grandy flybridge model. The last time I was doing a simple run the starboard engine lost all vacuum suddenly, dropped to zero, and I had to shut the engine down and just run the port one. I’m trying to diagnose the issue and was wondering if anyone knows where I can get a repair manual for this engine type. Any help will be greatly appreciated.

Hello, it sounds like the engine jumped time. Any repair manual for a small block GM will show how to replace the timing chain. Do a compression test and if all cylinders are low that is definitely the problem.

Is it possible for a transmission to run out of oil in 25 miles at 3000 rpm on a crusader 270? I fried mine and my storage marina said it was because the cooler was plugged, but the engines didn’t overheat . I didn’t check the fluid levels because they were suppose to be checked on spring commission. The dip stick wasn’t in place either. Total oil in the bilge was maybe two cups. No sign of vapor anywhere in the engine compartment. Two quarts of oil couldn’t vanish…The yard said their mechanic checked the oil.

There is a chance the oil cooler is bad and the oil went out the exhaust. You will need to pressure check the oil cooler. If it is holding pressure, then it is unlikely the transmission was full to begin with.