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muriatic acid then neutralized will eat aluminum off the journal then lightly sand it, but a hogged out bearing race is a different story. Wrap the journal with some cloth and tie it. Soak the cloth in muriatic acid and let it sit about 20 - 30 minutes, keep an eye on it and wear protective gloves. neutralize it in water with a little baking soda in it, then rinse it well. Immediately dry well and then coat with wd40. Polish with some 1500 grit or so of wet and dry using a piece wrapped around it with a piece of rope with several winds on it. Use a good machinist's / babbitt scraper to scrape the bearing journal and see if you can clean it up. If you use sand paper you may embed grit in the aluminum if you are not extra careful. Best guess is that if you take measurements using a micrometer, inside and outside, the engine will be a used engine still but it may run and service you for a few more years. It is 25 years old. Maybe a used engine from a mower bone yard may be a solution too.

Cfs said:

I am working on a John Deere JX75 a 21 inch self propelled mower approx 25 yrs old it has a Kawasaki FJ180V-AS11 engine. The connecting rod broke. When I opened up the engine I found the cylinder and piston and rings to be in great shape. The connecting rod journal on the crank looks good no damage there. There is however scoring on the crank at the upper bearing where it passes through the lid/top of the engine. The bearing is not replaceable it’s part of the aluminum lid. The complete lid is no longer available. What I can use help with is this: is there any way to dress/clean up the scoring on the crank and the scoring on the bearing surface. Anybody had any success stories to share? I was thinking that I could attempt to sand the crank with emery cloth and clean up the scoring on the crank. Not as sure what I could do with the lid
Any ideas welcome
Spit

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This poor thing has lived a long life. Sorry, it's time to let it go or find a better engine. There is no "polishing" that will save the crank journal and bearing surfaces. All that does it take metal away and increase the oil clearances. After that, the connecting rod will likely break and take everything inside apart with it.

Auto Doc's said:

This poor thing has lived a long life. Sorry, it's time to let it go or find a better engine. There is no "polishing" that will save the crank journal and bearing surfaces. All that does it take metal away and increase the oil clearances. After that, the connecting rod will likely break and take everything inside apart with it.

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It all depends the journal condition after the Muriatic Acid bath. And have everyone forget about installing sleeve bearings? Yes it take some research to find the right one.

Few important things about Muriatic Acid. Don't use it indoors. When using outdoor make sure to have good airflow as it will take your breathe away. Highly toxic at full strength. And after cleaning and neutralization the metal parts must oil immediately or they will flash rust. Also don't have anything in the area you don't want damaged as fumes is heavier than air most time and will settle in the area and cause steel to flash rust.

Cfs said:

I am working on a John Deere JX75 a 21 inch self propelled mower approx 25 yrs old it has a Kawasaki FJ180V-AS11 engine. The connecting rod broke. When I opened up the engine I found the cylinder and piston and rings to be in great shape. The connecting rod journal on the crank looks good no damage there. There is however scoring on the crank at the upper bearing where it passes through the lid/top of the engine. The bearing is not replaceable it’s part of the aluminum lid. The complete lid is no longer available. What I can use help with is this: is there any way to dress/clean up the scoring on the crank and the scoring on the bearing surface. Anybody had any success stories to share? I was thinking that I could attempt to sand the crank with emery cloth and clean up the scoring on the crank. Not as sure what I could do with the lid
Any ideas welcome
Spit

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The part number for the crankcase cover is 14041-7009, still available from Kawasaki. See your local Kawasaki Engine dealer. If it is not exclusive to Deere, they should be able to order. This engine was built in 2004.

Cool - from $30 good used on ebay to $86 from KW. I saw the price on a crank this morning about $50 so that is a bargain on a 20 year old engine. Be sure to measure the crank journals and rod big end (at least for wear) before ordering a crank to be sure it is STD and that the rod is not too worn.

Thanks to everyone for your input. This is one heck of a mower with a cast aluminum deck and is in great condition.

The concern that I have with the crankshaft is scoring not on the rod journal but at the top of the crank where it passes through the lid. Of course the lid bearing is just a machined surface in the aluminum lid and not a ball bearing.
I have seen this kind of damage in a Honda and a Briggs before. It is amazing to me, that the aluminum bearing surface is able to cause scoring on the steel crank but it does happen.
I have not pulled the crank out of the bucket and have not seen the comparable bearing surface or crankshaft condition at the lower bearing.
Anybody have a prediction on the condition of the lower bearing mating surfaces? I would assume that the lower would be less likely to be damaged since it is immersed in oil at the bottom of the crankcase, while the upper depends on oil being pumped up to lubricate the surfaces.

CFS

Pictures of your concerns would help us help you.

Auto Doc's said:

Pictures of your concerns would help us help you.

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I will do that later this afternoon. I put the engine back together so I would be able to remember how every thing went together. When I was posting the photos off the shattered connecting rod I was kicking myself for not taking photos of the lid and crankshaft

Cfs said:

I will do that later this afternoon. I put the engine back together so I would be able to remember how every thing went together. When I was posting the photos off the shattered connecting rod I was kicking myself for not taking photos of the lid and crankshaft

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Here are some photos of the upper bearing surface on the crankshaft and the damaged cast aluminum bearing surface in the lid. As I think I previously mentioned I have not disconnected the blade clutch and transmission pulley or removed the engine in order to remove the crankshaft from the crankcase. I think I am correct in thinking that the upper bearing depends on oil being pumped up to the top of the engine for lubrication, while the lower bearing is immersed in oil due to the oil laying on top of it in the bottom of the crankcase

Cfs said:

Here are some photos of the upper bearing surface on the crankshaft and the damaged cast aluminum bearing surface in the lid. As I think I previously mentioned I have not disconnected the blade clutch and transmission pulley or removed the engine in order to remove the crankshaft from the crankcase. I think I am correct in thinking that the upper bearing depends on oil being pumped up to the top of the engine for lubrication, while the lower bearing is immersed in oil due to the oil laying on top of it in the bottom of the crankcase

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Not to confuse things but here are a few photos of an old crankshaft that I think is fro a Honda with the same type of damage to the crankshaft

I was taught in machine work that the harder surface wears when combined with a softer surface when contamination is present. The expression was I think, "The softer material takes the charge and the harder material wears." People want to argue that all the time but think about it. Take a stick of butter out of the fridge, throw some glass shards, sand, woods splinters on it and press them into the butter. Rub it on something harder and see how much it scratches. The butter and contamination embedded in it don't wear much. The aluminum is soft enough that sand and debris is embedding in it. The contamination then wears the crankshaft.

That looks to be beyond saving, the seal groove and aluminum scoring tells me this thing was run low on oil. Here is a used long block engine I found on Ebay:

Who put sand in the oil sump? You have more issues than one crank bearing surface.

Look at all that grit inside on the parts.......... WOW!!! That is a filthy engine.

Thank ms to you all for your input. I was hoping that given the good condition of the piston & rings and the cylinder, I would be able to replace the broken rod and be back in business. Then I noticed the scoring on the crankshaft from and lid. I knew I should get input and advice looks like it’s destined to go to the recycling center

If it was me I would stick a fork in it and call it done. New to the equipment engine is needed.

Image 6678 says Nope. The only way to save that would be clean it up, oxy/acetylene metal spray process to build it up and turn it in a lathe back to specified diameter. Not cheap.

Cfs,
Wondering about where you're located and if you still have this engine? I just picked up an identical jx75 built in 2004 that I'm working on with my son. Still troubleshooting, but it sure looks like the piston rings are shot. Hoping to borrow a borescope from my neighbor later today or tomorrow to check out the piston and cylinder. I see that rings aren't too expensive so may go that route if everything else looks good.
If you're open to it I'd consider buying your good piston and rings (plus maybe a few other things) or if we live close I'd entertain selling the mower we have. Maybe one of us can make 2 broken engines into one!
Thanks!

If you know a good machinist, he may be able to turn the crank and put a bushing in the top main bearing as long as the area where the seal rides on the crank is smaller than the bearing area.

Hello hlw49,

The first challenge is finding an old school machinist that even knows what they are asking to be done. Second would be one who can actually do this. Third would be the cost of having such work done.

The old machine shops of "we can repair anything" have faded off terribly in recent years.

I came from the "shim the bearing inserts days" when shim stock was still being sold to many shops. That stuff is just not available these days.

Even dressing the bore a connecting rod by the machine shop has been next to impossible in my area.

Not too long ago, they used to actually surface weld and turn crank journals to stock specifications, but the practice has become way too expensive.