Murray 42828X8B restoration project

[blues124]

Greetings!
I was given a Murray model 42828X8B for free and I am going to use it to teach my kids about engines and maintenance. The previous owner said the mower hasn't run in 4 years. The "Mfg. Date" is 96057, so I believe that would be in March 1996? The engine (Tecumseh Enduro OHV16 204211B) appears to be in decent shape, but the body has quite a bit of rust and the tires are dry rotted since it was stored outside. I haven't tried to start the engine. The gas tank was flooded with water. Both it and the carburetor are fouled up with nasty black tar, but the engine oil was clean enough. The carburetor bowl has a pin hole rusted thru it, and was filled with something that looked like sand. I don't think I can rebuild it, I'll have to buy one.

The owner didn't have the key. I assume this is no big deal; I can either 'hot-wire' a new switch into it, or possibly even turn it with a screwdriver. Any ideas?

Any advice, warnings, etc before starting this project would be appreciated. I don't intend to sink a lot of money into it, but I don't mind the labor. My shop is reasonably equipped with standard tools. Let me know if there are any specialty tools I must have.. I'm sure I'll be posting several requests for assistance in the near future.

Thanks!
-Steve

 

[gfp55]

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Greetings!
I was given a Murray model 42828X8B for free and I am going to use it to teach my kids about engines and maintenance. The previous owner said the mower hasn't run in 4 years. The "Mfg. Date" is 96057, so I believe that would be in March 1996? The engine (Tecumseh Enduro OHV16 204211B) appears to be in decent shape, but the body has quite a bit of rust and the tires are dry rotted since it was stored outside. I haven't tried to start the engine. The gas tank was flooded with water. Both it and the carburetor are fouled up with nasty black tar, but the engine oil was clean enough. The carburetor bowl has a pin hole rusted thru it, and was filled with something that looked like sand. I don't think I can rebuild it, I'll have to buy one.

The owner didn't have the key. I assume this is no big deal; I can either 'hot-wire' a new switch into it, or possibly even turn it with a screwdriver. Any ideas?

Any advice, warnings, etc before starting this project would be appreciated. I don't intend to sink a lot of money into it, but I don't mind the labor. My shop is reasonably equipped with standard tools. Let me know if there are any specialty tools I must have.. I'm sure I'll be posting several requests for assistance in the near future.

Thanks!
-Steve

You can use just about any riding tractor key for the ignition switch. Parts are cheap on ebay. You can watch utube videos on carb rebuilding and replacement, adjustments. I would change the oil and filter. Do not overfill the engine oil. Make sure the battery cables are good and clean so you get good contact. Take the spark plug out and turn the key so the starter turns the engine over a few times and that will move the oil around inside the engine, don't hold the key no longer then 10 to 15 seconds, then let the starter cool for a few minutes, then do it again (2 or 3 times and the engine should be good and free spinning.) Make sure the plug is gaped to specs (you should do able to download a engine manual for your engine with the model number off the engine) That should give you a good start on you project. Keep us posted and have fun.

 

[blues124]

Thanks for all the great advice! I did take out the spark plug and could easily turn the engine, and now I've taken off the piston head and it is in great shape. The oil coming our was very clean, but I am changing it anyway, and a new filter of course. I also found a replacement key at Sears! Now I'll need to hunt down a replacement carb. The old one is really shot.
Thanks again.

 

[gfp55]

Thanks for all the great advice! I did take out the spark plug and could easily turn the engine, and now I've taken off the piston head and it is in great shape. The oil coming our was very clean, but I am changing it anyway, and a new filter of course. I also found a replacement key at Sears! Now I'll need to hunt down a replacement carb. The old one is really shot.
Thanks again.

When you say "piston head" I think you mean to say cylinder head. The part that the spark plug screw into, right? If the answer is yes then you will need a new head gasket and when you tighten down the head bolts you will need to torque them to spec in the right sequence or the correct order. Keep us updated.

 

[blues124]

Yes, exactly, the cylinder head. Thanks again, I knew the torque was important, but not the specific order. I do know to use a star pattern in general. I was also going to reuse the gasket (it's not damaged). Is that not acceptable?
Finally, the carb is shot. Online I'm finding them to be about $100. I've seen non-OEM manufactured carbs for a lot less, but not the one I need, which is Tecumseh part number 640000. Any ideas? FYI, when I say the old one is shot, it is completely corroded and the bowl has a hole in it, so it's not a simple rebuild.
Thanks again for all the advice!

 

[gfp55]

Yes, exactly, the cylinder head. Thanks again, I knew the torque was important, but not the specific order. I do know to use a star pattern in general. I was also going to reuse the gasket (it's not damaged). Is that not acceptable?
Finally, the carb is shot. Online I'm finding them to be about $100. I've seen non-OEM manufactured carbs for a lot less, but not the one I need, which is Tecumseh part number 640000. Any ideas? FYI, when I say the old one is shot, it is completely corroded and the bowl has a hole in it, so it's not a simple rebuild.
Thanks again for all the advice!

Its always best to replace a head gasket once it been used.

 

[blues124]

Its always best to replace a head gasket once it been used.

Sure, it's easy and cheap enough. Anyone have ideas on the carburetor?
Also, any advice on how to get varnish out of the bottom of the gas tank?

 

[gfp55]

Sure, it's easy and cheap enough. Anyone have ideas on the carburetor?
Also, any advice on how to get varnish out of the bottom of the gas tank?

Have you taken the carb off yet? If its not off maybe you should take pictures so you know where the springs and other things go when you put it back together. To see if you can save the carb, maybe you could take some pictures of the carb, the parts that you say bad, you may be able to rebuild it, a rebuild isn't that hard. the parts are cheap also. Is the gas tank metal or plastic? I have removed rust by removing the tank and putting about a half cup of pea gravel in the tank and shaking it for some time and the gravel will knock the rust or varnish off the bottom of the tank. After you shake it for awhile and check to see if the rust/varnish is broken loose, you dump out the gravel and rinse the inside of the tank with water and let it dry in the sun upside down. Keep us posted OK.

 

[blues124]

I have removed the carb, and did remember to take some pictures before doing it.
When I opened the bowl, I found it full of something that looked like sand. I assume something disintegrated, but I dont know what it was. The bowl has a hole, and the bottom bolt it frozen on with rust. The main jet looks pretty nasty and the throttles didnt want to move, but I've used some carb cleaner on them and now it's looking better. The float looks OK but I would replace anyway. The needle valve is shot. All the main body seems OK, so maybe I could rebuild. What so you think?
Also, the battery is totally dead and the part number is obsolete. This is a 12VDC system, right? Can I just buy a replacement at Sears/WalMart or wherever?


Thanks again for all your help. Good advice on the gas tank too - it's plastic. I've sprayed it with a bit of degreaser to get it started and then will try gravel. Hot water might help break it up too.

 

[gfp55]

I have removed the carb, and did remember to take some pictures before doing it.
When I opened the bowl, I found it full of something that looked like sand. I assume something disintegrated, but I dont know what it was. The bowl has a hole, and the bottom bolt it frozen on with rust. The main jet looks pretty nasty and the throttles didnt want to move, but I've used some carb cleaner on them and now it's looking better. The float looks OK but I would replace anyway. The needle valve is shot. All the main body seems OK, so maybe I could rebuild. What so you think?
Also, the battery is totally dead and the part number is obsolete. This is a 12VDC system, right? Can I just buy a replacement at Sears/WalMart or wherever?
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Thanks again for all your help. Good advice on the gas tank too - it's plastic. I've sprayed it with a bit of degreaser to get it started and then will try gravel. Hot water might help break it up too.

Your right about the carb, its pretty bad. You could try putting the whole carb in a bowl of automatic transmission fluid and letting it soak for about a day or two and then clean it up with carb cleaner and see how it comes out. If it comes out OK, you can get a rebuild kit that will have all the parts you will need to rebuild it plus you will need a bowl. You will need to clean the three tiny holes in the venturi, I use cutting torch head cleaning wires. The holes are small, so small that a pin is too big to fit in the holes. If you have a wire brush, you can pull one of the wires out of it and use needle nose pliers to put the wire in the holes. Lets see how it cleans up before you go any farther with the carb. Yes it is a 12 volt system and you can get a battery at Walmart, Just make sure the positive and the negative posts are on the correct sides. Take you old battery with you so you get the right one and you won't have to pay the core deposit. Keep us posted OK