I have an old mercury 1977 115hp outboard motor when I run it on the hose it's perfect but as soon as it's on the lake and has pressure it looses power, I can get up to speed for maybe 30 seconds but then will loose power and go back to idle or cut out then a minute later can get back up to full...
i can't seem to find the engine serial number which makes it very difficult to find the year model so far i have found the serial numbers for most components, the 1/2 block serial number i found could be from 1970 - 72 but the water jacket cover serial number said it was the 1980's i have found...
