25hp XD shift linkage disconnect?

[killforfood]

The Big Brown Truck should deliver my water pump kit (1985 Merc 25hp XD) from iboats today.
I?ve read through a couple tutorials on how to drop the lower unit and it all looks fairly simple but I?m still a little sketchy on disconnecting the shift linkage.
One said there is a C clip to disconnect from above. Another talked about a couple nuts that need to be undone mid way up. I?m not sure which applies to my particular motor.

One other question; is there an acceptable automotive gear oil that will work in the lower unit? The word ?Marine? generally doubles the price of everything and with kids in private school, nickels add up.

 

[will941s]

Re: 25hp XD shift linkage disconnect?

Your motor probably does not have the c-clip. To disconnect the shaft, remove the starter, look under it and you will see the cam holding the shift shaft. On the front/top of that cam there is a screw, remove that screw and pry the side of the cam off. Then you can remove the lower unit. If is does have the c-clip just pop the c-clip up and remove the shaft. The cam over the years did'nt change, they just went from a screw holding the side of the cam on to a c-clip. I'm not really sure why you have to use marine lube, but I never tested the theory and have always used it. You use so little to fill the lower unit that your not going to really rack up a bill buying marine lube for the lower. I know I did use regular grease on my steering once instead of marine grease, and now i'm waiting my my new teleflex quick connect helm to come in the mail now. If it calls for marine, use it.

 

[killforfood]

Re: 25hp XD shift linkage disconnect?

will941s,

You?re right it was the cam type with a screw going through a horizontal shaft. The screw was seized tight in the shaft and I finally gave up and chose to shear it off just to get things apart. I may have to make a new shaft if I?m not able to get the broken off threads out.
The lower unit nearly fell off on its own once the four main bolts were undone. Water pump replacement was easy except for that pesky pump cover o-ring wanting to fall off. I solved that with a liberal dose of Vaseline to hold it in place while I slid the cover down the shaft.
The lower unit gear oil had streaks of muddy oil in it so I flushed some new oil through it to clean things out. That gear oil pump was the best ten bucks I ever spent. I tend to be really cheap and almost didn?t buy it. I was thinking of just using a big $2 farm supply syringe but am really glad I bought the pump instead.
I still haven?t sorted out why I?m burning fuel faster than the carb will pump it but just to be sure, I pulled the reeds. They looked fine. The carb is clean with no deposits or clogged orifices. I?ll replace all the gaskets, just to say I did, but I doubt that?s the problem. I?ll replace the fuel fitting on the engine and install all new fuel lines (for the third time) but for the life of me I still don?t know why I?m not pumping fuel fast enough to keep up with demand.
I?ll get the muffs on it tonight and get the idle jet adjusted. Tomorrow I?ll hit the river and see how the new Solas prop pushes. The new Solas despite having identical numbers as my old chipped prop, is very different. Same diameter but much shorter and thicker blades??? We?ll see.

 

[will941s]

Re: 25hp XD shift linkage disconnect?

Props have different blade designs to make the boat do different things. Like cupped blades grab and hold better, progressive pitch get you to RPM's faster, regular blades hold good but a little less acceleration....just little variations in the design of a prop makes a world of difference. As far as the using more gas than get can be supplied, Check your pick-up tube in the tank to make sure it's not clogged as well as the gas tank vent....sometimes you need to clean it or you wont get good fuel delivery. Check the filter on the motor and the motor connections for cloggs. Also you can get a carb kit and rebuild the carb...very easy (under $40). Use ole wally world super tech carb cleaner and some compressed air and clean out all the little passages in the carb; sometimes even though it looks clean, those little passages can hold a little bit of sludge that you can't see. And change the plugs.