mercury 50 hp lower unit wont come off????

[greg98926]

I am trying to take the lower unit off and it will only come down about 1/8 of an inch. I removed all the bolts and the shifting pin under the carbs but it is stuck on there good. Is this something to do with the drive shaft corroded into the power head???? I am taking it off because when I shift it into reverse the motor wants to pop up. Looks like something came unhooked inside the lower unit that moves the rod that makes the motor stay down when in reverse??? Any help would be great.

 

[ONERCBOATER]

Re: mercury 50 hp lower unit wont come off????

your post isnt very clear? "makes the motor pop up when put in reverse"????
that could be as simple as having the tilt lever released as you would if you running unknown waters that might have obstructions. with tilt released when you put it in reverse engine will tilt if more than the slightest throttle applied. maybe you dont have an issue beyond that. no offense intended but how much experience do you have with boats in general and esp outboards?

I cant think of anything in lower unit that would cause the entire motor to move up when shifted into reverse...so perhaps better if you explain in detail and pretend we cant see it.... so that we are all on same page.

Other needed info..what year is the engine.... what model, serial number (you can keep last 3 digits to self if worried) does it have power trim? or is it manual?

yes it is possible for the driveshaft to get corroded into place.... is this a saltwater engine? has it ever seen salt water? that may be an issue to look into...when was last time lower unit taken off? water pump replaced? do you have shop manual for it?

The more information we have the more helpful we can be.

Sean

 

[MercMan82]

Re: mercury 50 hp lower unit wont come off????

The fact that the lower unit wants to pop out of the water when put in reverse means that reverse is working. When your motor is put in reverse, the motor is supposed to be locked in place to keep this sort of thing from happening. More info will help us determine how your motor is configured. However, the lower unit does need to come off because as onercboater mentioned, your motor is in need of a water pump kit; impeller, gaskets, o-rings.

 

[bgc]

Re: mercury 50 hp lower unit wont come off????

Greg,
Are you sure all bolts and nuts are removed?

At the shop, when a shaft is stuck, we flip the motors over use a wood wedge to open the case ?just a bit? and squirt KROIL inside on the shafts. We then let it sit for a day or two and then gently try easing the lower off. KROIL is one of the better penetrating oils we have found for removing stuck/rusted parts.

Good luck, go slow, don?t force anything, and have a manual for the motor handy.

 

[Gibbles]

Re: mercury 50 hp lower unit wont come off????

oh boy

I had this issue with a Mercury 200 20hp.
Triple check that you got all of the bolts out, including the one for the trim tab at the front...

With mine the drive shaft was rusted and stuck, I managed to get some space using a flat prybar on the front, and another on a bolt in the rear...

Then I flipped the engine up side down, and went to town spraying with some seafoam deep creep trying very hard to spray in the general direction of the drive shaft to power head seal, and also trying to hit the drive shaft in hopes that it would run down the shaft (I used a whole can)...

From there I let it sit for a few days and went back to prying.

It started to slowly slide out, and then dropped!

I swear by this stuff http://www.brownells.com/.aspx/pid=20900/Product/C5-A-ANTI-SEIZE-LUBRICANT

I use it on everything from guns, sparkplug threads, and anything else I want to come apart later on down the road.

 

[greg98926]

Re: mercury 50 hp lower unit wont come off????

Thanks for the info everyone. I have removed all the bolts and nuts. The motor I just got for free. I started it up and put it into gear and noticed that when I put it in reverse I could lift up on the motor. The mechanism that should drop down when put into reverse stays in the same spot no matter what gear you are in (F/R). That is why I wanted to pull off the lower unit. while I had it off I wanted to change the water pump also. This motor has been in salt water. All the other bolts came off easy. will keep trying to get it off. I will try to turn the engine upside down and spray inside to help get it off. I will keep you posted. Thanks Again!

 

[FLATHEAD MAC]

Re: mercury 50 hp lower unit wont come off????

GOOD LUCK WITH dropping LU. sounds like the reverse lock out cam is eityher broken or missing. came across same issue with buddies motor dropping the LU multiple times getting shifter correct to find out cables had been reversed, not noticing the cam missing until double checking shift after getting cables correct. baught a cam and all works well. there fairly reasonable $$