1972 Merc 1150

[steriosm88]

I'm looking at buying a 17 foot Starcraft aluminum bow rider with a 72 115 on it. Motor looks good but they all do. How do I go about giving it a compression test? I have a tester I use on cars. Do I pull all the plugs and crank 3 times for each cylinder? Anyone know what sort of compression i'm looking for? A marina guy up here sais it will be hard to get parts for something that old. Are they reliable motors? Great site. Glad I found it. Should help steer me to a great boat. Thanks

 

[Chris1956]

Re: 1972 Merc 1150

The compression test is the saame as a car. Crank it until the reading is max. That motor should have 100+PSI and nearly even on all cylinders. The bottom cylinder will be difficult to test.

These motors are a good, proven design. The distributor ignition is good, but parts are expensive and a bit hard to get. If you can do all the maintenance and repairs yourself, you may want to buy the motor. Most shops won't work on them!