Mercury 500 Thunderbolt - Sat for a very long time.

[Loozerdk]

Never did get around to post the video of it started, got my parts in the mail today, so with a bit of luck the Mercury will be ready for a test this weekend, depending of the Danish weather.

 

[merc850]

Since the battery only operates the starter you just use a charger (solar or A.C.) once in a while to keep the battery up. You are going to have to replace the tilt tube to use a rack and pinion steering system. I think you should remove the powerhead and check the upper shift shaft for corrosion it can break and you're stuck.
That's a nice boat you have.

 

[Loozerdk]

Hi Merc850.

I was thinking about removing the powerhead, but i fear that most of the bolts are going to snap - since the engine lived its life in saltwater, but i am planing on keeping a small electric outboard in the boat in case of an emergency.

The boat came with a wire steering system, so for now i will be using that, if i find a cheap tilt tube, i will replace it.

I was thinking about a solar panal, don't need much power, only for navigation lights (Im going for LEDS) and some music, will be fitting a 75 Ah battery, so that should be more than enough.

 

[merc850]

The powerhead is held on by nuts that attach to studs in the block, these may be stainless steel so it may come apart easily.

 

[Loozerdk]

The powerhead is held on by nuts that attach to studs in the block, these may be stainless steel so it may come apart easily.

The keyword is may.

If it will be a problem, there is no other solution than pulling the powerhead, still waiting for a chance to work on the engine, i hope a reseal of the lower leg will fix the water in the oil problem, but time will tell.

 

[Loozerdk]

Finally some time to work on the engine, got the lower leg off, no problems in that, also got the shiftshaft seal changed.

That was the good news, the bad news is that the driveshaft is pretty pitted from rust, not sure if new seals are going to change anything if installed directly. I did however read something about a speedi sleeve ? Does anyone got the part number for that ?

Prop is also stuck, been hammering it with a pretty big rubber mallet, and no dice, so far.

Here is a picture of the shaft, sorry about the quality, and don't mind the dirt - picture was taken before cleaning.

 

[Loozerdk]

Update:

Prop is off, unfortunately in 10 pieces, it was siezed solid to the shaft, so had to cut it.

Also got the seal removed from behind the prop, strangely enough there was only one, according to the manual there should be two ? Maybe its on the newer models only ?

Does anyone know what the stock prop size was on a 1974 Mercury 500 ? Can't find any markings on the old prop.

 

[jimmbo]

Mercury did not install/ship a 'stock' prop on its engines. Every installation used a prop selected by the dealer depending on what boat it was installed on.
Are you certain there was only one seal? They are installed back to back with each other, The seal you removed, was the rubber lip facing out or in?

 

[Loozerdk]

Yes, there was only one, the seal removed was with a double rubber lip, meaning there was one on each side.

Seal looks like this on both sides:

 

[jimmbo]

Then you only need one. There was probably an update because of too many installs where both seals were installed the same direction, or it might be an aftermarket part that was designed that way.

 

[Loozerdk]

It is an aftermarket part, so thats most likely why.

Good, i will just install that one seal then.

Then i just need to figure out what size of prop i need.

 

[Loozerdk]

Can anyone shed some light on what the difference is between the props that fit the 1977 and forward series and the older 1974-1976?

I am looking for a new prop for my 1974, it has a 13 spline prop shaft, if it would be possible to fit a prop from a 1977 and forward it would make the search much easier.

 

[jimmbo]

Here is a service bulletin from merc explaining the changes

http://boatinfo.no/lib/bulletins.html#mercury-service-1976_14

 

[Loozerdk]

I am not 100% sure if i understand that correctly, english is not my native language.

There was only a forward thrust hub when taking the old prop off, so maybe it had already been replaced with the newer style before i got the engine.

So if i understand correctly a prop fitting a 1977 and forward should also fit a 1974, as long its using the new style thrust hub ?

 

[Loozerdk]

No Title

So time for an update.

I ended up pulling the waterpump and base again, and installed two speedi sleeves on the shaft, had some problems with a leak after that, but i turned out to be the prop shaft seal not seated properly.

Engine is more or less back together, waiting for a set of new fuel lines, and a rebuild kit for the fuel pump.

Then the last thing is a new prop.