Re: 1991 evinrude 225 hp
Not sure what ol' jonesg is talking about here....I don't see anywhere in the original post about this being a re-built powerhead.
Do get a factory service manual, though. Not a Clymer or Seloc.
Anyway, it is a good engine. The flywheels are not too bad to get off, but you absolutely need a tough, beefy puller, not a toy. Get a good one.
The flywheel nut is torqued to 140 ft-lbs, and you need to make sure the key is in the groove correctly. The pull of the magnets on the flywheel kinda makes it tough to get the flywheel back on with the key aligned properly. It is definitely doable, but just be careful with the alignment.
Look the carbs over carefully, pull the HS jet in each one, and look for gunk and varnish. If dirty, clean the carbs thoroughly, or you can lean out a cylinder, and THEN the powerhead will need re-building and break-in.
It has a water valving system that I am not crazy about. The throttle controls water flow, and if that system is not right, you can have cooling problems. The newer V6 loopers don't have that valving system, and I think it is very possible to upgrade yours to the newer system. There might be problems with switching from Vernatherms to the newer thermostats due to the thremo seats in the heads....I don't know for sure. Just be aware that the water valving system should be working just right for proper cooling.
VRO/VRO2/OMS pump is a good system, but I have disabled the oil injection on my engines, and I am pre-mixing my gas. There are plenty of posts on here regarding how to do that modification. I have found more than one pump that was working but working weakly, that the torx screws holding the diaphragm covers were loose, causing slight air leaks and weakened pump output/volume. If you have the pump off for any reason, make sure those torx screws are firmly and EVENLY tightened, one-eighth of a turn past head contact with the plastic body.
