1971 Merc 800 rebuild / refurbish

[CrossCurrent50]

Re: 1971 Merc 800 rebuild / refurbish

Hi Moody blue I believe the bearing your asking about is a double row bearing and the inner diamiter is metric. Use this add to get the info and compare it to your old bearing off the engine. 16878 New No Box SKF 3206 ATN9 Ball Bearing Double Row 30mm ID | eBay W5206 bearing measurements http://www.ebay.com/itm/JAF-Sealed-...002?pt=LH_DefaultDomain_0&hash=item35c40e0d92 5026 angular contact bearing http://www.ebay.com/itm/5206-Angula...803?pt=LH_DefaultDomain_0&hash=item53ebc699b3 Need to find out which 5026 is the one yours need as they have different measurements. The width may be able to be adjusted with a shim

 

[Moody Blue]

Re: 1971 Merc 800 rebuild / refurbish

Bearing issue is resolved. I ended up buying off ebay. Cost more but I got what I needed.

I have spent a couple days working on removing the bolts from the exhaust baffle plate which is mounted behind the outer exhaust cover. All the bolts were seized, but I managed to get them all out in one piece. Lots of penetrating fluid and patience.

My problem now is trying to free the exhaust baffle from the block. Its been on there for 42 years, and seems to be intent on staying there. I don't want to break or bend it trying to remove it. Any suggestions on how to separate the baffle from the block?

 

[daveswaves]

Re: 1971 Merc 800 rebuild / refurbish

Bearing issue is resolved. I ended up buying off ebay. Cost more but I got what I needed.

I have spent a couple days working on removing the bolts from the exhaust baffle plate which is mounted behind the outer exhaust cover. All the bolts were seized, but I managed to get them all out in one piece. Lots of penetrating fluid and patience.

My problem now is trying to free the exhaust baffle from the block. Its been on there for 42 years, and seems to be intent on staying there. I don't want to break or bend it trying to remove it. Any suggestions on how to separate the baffle from the block?

Make sure you did not miss a bolt, perhaps hidden under carbon. When all the bolts are out you should be able to get it lifted with a wood chisel or similar tool.

 

[Yesterday]

Re: 1971 Merc 800 rebuild / refurbish

Geeze man, I'm reading this thread and praying I won't have to go through anything similar!!!!!!!
Lotsa luck MB, though it sounds like you have things well under control!

 

[Moody Blue]

Re: 1971 Merc 800 rebuild / refurbish

I managed to get the baffle plate off without breaking anything. Yeh. All thats left now is cleanup, wait for a few more parts to arrive and then begin the assy process.

WHat is the best way to clean up all the carbon/crap? Was thinking Seafoam or Deepcreep.

 

[Yesterday]

Re: 1971 Merc 800 rebuild / refurbish

Actually seafoam makes DeepCreep and it's what I use as a penetrant. Doesn't seem to do much for carbon.
If we're talking mixed with 2-stroke oil I use dollar store scouring pads and Varasol. Even Carb cleaner didn't seem to do much with the carbon and you have to be careful what that stuff lands on. Some use brake cleaner and others kerosene, though I've not tried either of those.

 

[buzzm19]

Re: 1971 Merc 800 rebuild / refurbish

MB, I use berkebile 2+2 gum cutter, it is the best cleaner I have found out of all carb cleaners, It is some real nasty stuf and be sure you use it in a ventilated area. The only thing I found that is realy the ultimite is the napa carburator cleaner in the gallon container, its napa Mac's 6402, this stuf is realy bad (it will completly destroy a carbuter if you soak it over night). It is a little pricy(36.00 us), to give you an idea of how bad it is, one time I dropped a bolt in it and was too lazy to fish it out, I just reached in and got it out with my hand and when my hand hit the air I couldn't get to the sink fast enough to wash it off (picture battery acid only about 100 times worse). I only use the carb cleaner (Mac's 6402) on really bad carbon build up and usually brush it on with an acid brush then let it sit a bit and rince it off. Buz

 

[Moody Blue]

Re: 1971 Merc 800 rebuild / refurbish

Was thinking the Seafoam approach because it is commonly used to decarb an engine.

Buz, thanks for the info on the carb cleaners. They sound a little harsh for use in my small shop which is closed up tight in the cold weather. Sounds like it would get the job done though.

 

[Moody Blue]

Re: 1971 Merc 800 rebuild / refurbish

Started the tedious process of removing the old stuck-on gaskets from all the surfaces. Bought a can of Permatex Gasket Remover for the job. Worked reasonably well on the gaskets but needed several applications to get the job done.

Don't know what's in this stuff but I discovered by accident that it works as an AMAZING carbon remover as well. Sprayed it on the worst deposits and you could see it start to disolve immediately. Within a couple minutes the carbon was reduced to a goopy black liquid. Wiped it up with a bunch of rags and problem solved. Thought others might like to know this little secret.

 

[Yesterday]

Re: 1971 Merc 800 rebuild / refurbish

Yessir, thanks for sharing that one! re: gasket removal, Ive been researching. Check out Roloc Bristle pads. Seem fairly quick to remove!
Honda-Tech: How to Remove tough gaskets - YouTube

 

[Moody Blue]

Re: 1971 Merc 800 rebuild / refurbish

Now that is a cool tool. Makes short work of the gaskets, and seems to be intended specifically for aluminum. My concern in watching the video is the speed of the tool in the die grinder. At that RPM, I wonder if it creates enough heat to deform the gasket surface. By that I mean round off the edges and create a slight "hump" on the gasket surface, or even make slight depressions. The operator did move the tool around at a fast pace, maybe to avoid that possibility.

Wonder if they are sold in Canada?

 

[buzzm19]

Re: 1971 Merc 800 rebuild / refurbish

MB, I have used the scotch pads on mine and they work good, I keep used ones around and use them on the soft aluminum, it seem that new ones are still too abrasive (my opinion). I have a varible air tool and I cut the speed way down and use a light amount of pressure and that way I cut way down on the heat and also move around a lot. Buz

 

[Moody Blue]

Re: 1971 Merc 800 rebuild / refurbish

Had a chance to take a closer look at the four "good" piston assy's and found something questionable.

On two of the assy's the piston pin is loose in the piston. I can slide the pin from side to side (between the retainer rings) with my fingers. On the other two assy's the pin is tight. From what I've read, the piston should have to be heated before being able to remove the pin. It seems then that the two piston assy's with the loose pin are no good?

I do have two other piston assy's that I had set aside because there was slight erosion on the top of the "eyebrows". The piston pins in these pistons are tight. Could/should these assy's be used?

 

[buzzm19]

Re: 1971 Merc 800 rebuild / refurbish

MB, those piston pins (wrist pins) are a press fit, thats a must. Buz