1976-77 150 merc outboard

[daphniesman04]

i have an merc outboard. it is either a 76 or 77 150 horse power. i ran it about a summer . set it up. last summer got it ready and put it over . ran it out and lost fire on some cylinders i guess becase it would just about die out. a few loose plug wires need to be replaced. but when i pulled the cowling i noticed there was a bit of corrosion around the 6 or bottom plug whole. pulled the plug and had water in it...is this serious or do i fix it or do i get a new outboard...please help me

 

[Chris1956]

Re: 1976-77 150 merc outboard

Water will usually get into the cylinder three ways. Your motor may have defective lower crankshaft seals, a warped or rotted out exhaust baffle, or a warped or rotted out inner water jacket cover under the exhaust cover. There is no test I know of to determine which of these it is. The tricky part of replacing the water jacket cover or exhaust baffle is removing these items without breaking the bolts that hold them on, especially if the motor was used in salt water. The lower crank seals are easy to replace, once you remove the powerhead. If you are serious about doing the repair, get a manual, a torch and an impact driver and try it. If not, you can buy a rebuilt powerhead for $2-2.5K