73 Merc 500 bring back to life

[Gonehunting]

Hello all, new to forum first post. I picked up this merc 500 and hope to get it running and installed on my 16' sea nymph. I have had it running for short periods on a stand but noticed i had no water from coming from the small tube at rear of motor which i just purchased an impeller and gaskets just in case they were needed. Will install regardless at some point. As of now i am removing fuel lines and also the three lines that come from and back to the case. Can anyone tell me what these lines are for are they vacuum lines? Any help would be great. Also i noticed the lowest fitting has a plugged orfice in it any thoughts?

 

[Gonehunting]

Any feed back could sure use the help, have a couple more questions!

 

[flyingscott]

Those lines are oil recirc lines for the bearings to keep them lubed, I believe. The biggest problem you will have is the wiring Mercury motors of that vintage have issues. If you have a tell tale on that motor it could be plugged. Change the waterpump now. Put up a pic of those items.

 

[Gonehunting]

Just got the new impeller installed, and am trying to get the lower unit re installed. Having issues with shifting once back together

 

[Gonehunting]

[No message]

 

[Gonehunting]

Flyingscott i thought that might be what the hoses were for thanks for reply, once i got all new lines installed mixed a gallon gas with sea foam it fired right up but no water from tell tale. So i started in on watet pump. After installing new pump i seem to be having issues getting the lower unit back together and alligning shifter properly. Anyone have any ideas

 

[flyingscott]

Look at the stickies at the top of the forum. Tells you how to reinstall those lower unit.

 

[Gonehunting]

Take a look at my pic am i missing part of the cam or is it all there?

 

[Gonehunting]

In regards to shift shaft setup i guess my problem is i dont have my cables connected to a throttle control, so once i have shift shaft in correct position without knowing where the cable neutral is, i am at a stopping point. untill i get a replacement control box. I was hoping i wouldnt have to make any cable adjustments if i was lucky enough to find the same model of throttle controls

 

[Gonehunting]

So now i have the lower unit back on and i started the motor with the new impeller but it is only spitting water from the tell tale. Any thoughts on how to back flush any debris i see there is a plug on the head.

 

[Gonehunting]

Ok so i pulled the plugs again to do a compression check and now that i am getting some water to tell tale it looks like i also have water in cylinders. Pluggs are wet. Seem like either a cracked head or gasket would make since. Any chance it could be something simple or just wishfull thinking.

 

[Gonehunting]

Any thoughts

 

[racerone]

There is no cylinder head on that motor.----There is no head gasket either.

 

[Gonehunting]

Okay so i didn't realize there were no heads on it, how about a little extra info that would help in diagnosing what might be the issue and what it might take to get it running again.

t

 

[Gonehunting]

Top three cylinders have 120 psi, no fitting to take a reading on the bottom one yet.

 

[Gonehunting]

Before. I started pumping water in the engine i was able to get it started and idle. Spark so far on top cylinder was blue and looked strong

 

[BG0666]

I have a 74 5000 wouldn't go into N-R is stuck in drive as I dug deeper I noticed that the shift linkage cam was spinning on the on shaft that goes to the lower unit.there is a roller pin I assume that it is a set pin?? It's pushed out 1/8 of a inch does that come out or something? Or do I need to pull lower unit?

 

[Templar7]

I have a 73 500 as well. Anyone have any idea what they are worth. I'd like to sell it but don't really know where to put a price. Any advice?

 

[racerone]

Price depends on the demand.------Availability of a shop that will work on them.------Many areas those motors end up in the recycle bin.