140 Mercruser restart after 16 years in storage

[Pinkfloyded]

First of all I'm new to this site (Not to boating) and would like to say "Hi" to everyone.
I recently purchased a 1986 Thundercraft Nova which has a 140 Mercuries engine(Not sure of the year). The boat has set in an unheated boathouse for the past 16 years. I believe that it has seen salt water at one time but I know that it was run for at least 2 years in the lake that I live on before the owner passed away. Since that, it has never been running. I know that the plugs were pulled and oil put in each cylinder at the time of it's final fall layup but that was 16 years ago. All my past experience has been with outboards and this inboard stuff is all pretty much new to me. I haven't even hooked up a battery to it yet and I know that I need to get oil circulated back up through the motor before I even try to start it. I see that some of the hoses will need to be replaced but other than that the wiring and everything else looks good.
Anyway, where do I start? :facepalm: The boat otherwise is in great shape considering it's history and I would love to see it running the lake once again.
Please Help

 

[86 century]

Re: 140 Mercruser restart after 16 years in storage

I would start by pulling the plugs and spray some wd40 or oil of your choice in the cly.
Pull the distributer and rent buy or make a oil pump drive tool. Spin pump till you get oil pressure.

It may be best to pull the drive incase the ujoints or gimbal bering have stuck over the years.
I found this out the hard way and now have a Gimbal housing and input shaft that are trashed.

 

[90stingray]

Re: 140 Mercruser restart after 16 years in storage

Since you are pulling the drive... I would go ahead and get a fresh impelled in there too.

 

[fishrdan]

Re: 140 Mercruser restart after 16 years in storage

At 16 years the bellows will need to be replaced, this will go along with pulling the drive. The bellows might not leak immediately, but they usually have a 5 year life.

You can start the engine and get that squared away before doing the bellows, but replace the bellows before taking it to the lake. A leaky Ujoint bellows can get expensive real quick.

Oh yeah, lube up all the zerks on the gimble housing, Ujoints, gimble bearing, coupler splines.

Yeah, there's a lot of things to do for an I/O that's been sitting 16 years.

Ya know something, I'd make sure the engine AND drive work before investing a lot of time/money into the boat. Who knows what condition the boat was in when it was laid up. My buddy bought a boat, rebuilt it,,,, then on the maiden voyage found that the drive was shot. $1900 later :facepalm:

 

[dingdongs]

Re: 140 Mercruser restart after 16 years in storage

may be best to see if the engines seized first and when we all know the outcome we'll let you know as its your money!!!!!
may be best to pull all four plugs out and put engine in forward and see if you can rotate engine over by rotating prop by hand.this should rotate engine in one direction and you'll hear the drive clicking the other direction.if engine doesn't rotate this is the time to see what course of action to take and what will be the cheaper way to proceed.let us know outcome of this quick test.

 

[Pinkfloyded]

Re: 140 Mercruser restart after 16 years in storage

Thanx Guys for all the quick responses.
It's raining here today but like "86 century & dingdongs" suggested, I'll get some oil in the cylinders (I heard that transmission fluid is good?) and see if everything is moving freely before I go any further. I'll let you know how I make out.
I found a PDF service manual for the out drive and another for the engine but I'm not exactly sure of the year of the motor, the boat is an 86 by the serial # but the service manual for an 86 140/3.0l Mercruser looks a little different in the illustrations but I assume they are all basically the same engine? For instance, the one in the manual shows two belts on the front and mine only has one and the air filter on the one in the manual is square and mine is round? Maybe the motor is an 85 or older. The specs on my motor are Serial # 6903191, Model # MCM 140, Displacement - 181 CID, Oil - SAE 30 SE, Plugs - AC-R-43T, Max W.O.T. R.P.M. - 4200-4600. Any help here or where I can get the proper manual would also be a great help.
I did check the bellows "fisherdan", and like you said they will need to be replaced (badly cracked)
so I will definitely will be pulling the drive.
Anyway, thanks again guys, and I'll keep you posted.