Johnson 75hp 1977 Replaced impeller, housing and impeller plate look good. Also shaft seal looks ok. Motor in water tank up to bottom of gav fin. No signs of water flow from discharge holes.
May not be deep enough in the water. The pump is above the fin. The water pump design is not a true positive displacement pump and therefore cannot be depended on to prime itself unless submerged in water.
Do the discharge holes need to be sumerged. If so, how do you confirm flow, also when on plain holes are out of water(discharge holes). Tried using hose like muffs to push water in the intake holes still no water flow. Should some water flow from the two exhaust holes or some other pee hole even before the thermastat opens.
Water should be coming out of the prop. Put your hand on top of the heads and see how hot it gets. Should be able to keep your hand there for 5-10 seconds without burning yourself.
I'd like to thank you for your replys. Is there a web site to get schematics without having to buy repair manuals. I'll submerge drive over disgharge holes and try again. The owners manual only shows water discharge from holes gust above<br />gav fin. Ran motor one time until alarm sounded to confirm electrical circuits worked. Motor has been in storage for three years.
For exploded views, you can go to ishopmarine.com, click Parts Lists, and drill down to your outboard model.<br /><br />However, it's very unwise to work on these engines yourself without a proper service manual. Having one on hand will keep you from making simple mistakes that can seriously damage your outboard. Highly recommended.
Found the root cause of over heating. after runimg motor again in deeper water, still runing hot. Put muffs on to see if i could push water up system to check for blockage, but still no water thought system. Droped lower and turned on water using muffs, found that shaft seal was replaced with home made packing that leaked under pressure enuff to not push water up supply tube. When replacing impeller you should automatically change all seals and gaskets new at same time to insure that run life last the same time.
