Is there an inspection plate on the block I can remove to search for obstruction? And last question....how much of the cooling water is supposed to discharge from the tell tale and how much through exhaust?
1977 50 HP Ran into 1' mudflat and killed motor. Poled out to deeper water and restarted engine but got no water flow from cowling tube. Dropped lower unit at the house and remover water pump. No clogs or issues to be found in pump assembly or lower unit intake screen. Blew compressed air...
My 1977 50 HP should have a 2/1 ratio as suggested by experts on this forum. I bought a used LU that seems to have around 1.75 to one. My question is.....wouldn't a 1.75 turn the propeller shaft faster than a 2 to 1 Ratio? If I'm getting a full prop rev before I turn the drive shaft twice, then...
Yep! I had it one spline wrong. Thanks so much for posting this. It will go into the Merc file! The crazy thing is, I have owned the engine for ten years and replaced water pump impeller at least twice before. I must have gotten really lucky with the installs. Either that, or I never removed...
Yikes! Never knew there could be different ratios. I bought it used, obviously, so I didn't know it could be different. I'm re-install and see what happens. Is the ratio printed in some type of model number anywhere on the LU?
thanks!
I ended up buying a lower unit that had the correct shaft length. Thanks for your help. My issue now is correctly installing the lower unit. I have started another thread if you have a chance to view.
thanks
1977 50 Hp Merc 500
Original lower unit destroyer on rock. Replacement is having issues shifting and running. Engine starts and idles fine but when shifting into forward, engine dies repeatedly. After several attempts I can slowly nurse RPM's up until it stopes at about 3/4 throttle. Not enough...
I removed pinion gear bolt, but the water pump base is preventing me from lifting the drive shaft out. I thought this was something I could handle but I may take it to a local mechanic that works on old Mercs. He warned me that swapping shafts may require shimming to achieve proper fit.
thanks