Onan CCKM-MS/2050G Engine Repair

thank you gentlemen , and to you @mattthemuppet2 for the suggestion of lye
i'll expose the offending aluminum on the journal before i condemn the crankshaft

now to get some drano....
 
fingers'n'toes crossed. Careful with the lye, it heats up alot and causes nasty azz fumes. It also works really fast if you heat it up a bit, plus the rest of the engine will be squeaky clean too afterwards. Just make sure nothing else aluminium goes in there!
 
Jeez did the PO run it completely out of oil? Sounds like my brother.
Regarding aluminum as a bearing- Alfa Romeo runs the cams directly in the alloy head and it works fine-
as long as there's oil in the engine! :)
-M
 
markba633csi said:
Jeez did the PO run it completely out of oil? Sounds like my brother.
Regarding aluminum as a bearing- Alfa Romeo runs the cams directly in the alloy head and it works fine-
as long as there's oil in the engine! :)
-M
Click to expand...
yes sir,
there was only about 2 cups of molasses-like substance that may have been oil at one time

it is common practice in many small engines to run aluminum against steel
i have seen it in camshaft support, connecting rods, and crankshaft support
as long as oil is supplied, and the reciprocal clearances can be maintained, the assemblies can last a long time
but we have to supply adequate pressurized oil to keep the con rods lubed, or we get what we got here! :eagerness:
 
Ah yes the molasses-like substance often found in Harbor Freight bandsaw gearboxes LOL
Are the cylinders and block all one piece on that engine? Or do the cylinders detach?
 
Last edited:
markba633csi said:
Ah yes the molasses-like substance often found in Harbor Freight bandsaw gearboxes LOL
Are the cylinders and block all one piece on that engine? Or do the cylinders detach?
Click to expand...
the cylinders are integral to the block
it would be sweet if the cylinders came off though!
 
I should have known this. Back in the 70s I had a Westcoaster Mailmaster 3 wheeled vehicle that had an Onan in it like that
I used to haul my girlfriend in it in the back like a sack of mail LOL
Never had to rebuild it tho, it actually ran good for several years
-M
 
Update...
i took a couple pictures of the progress in dissolving the aluminum smear.
i'm dissolving 1T of 100% sodium hydroxide in about 1 ounce of water, to make a thin syrup like consistency
the process is taking a long time because i'm doing the job in situ, brushing it on with a solder paste brush
i packed the engine block with paper towels to prevent lye leakage into the engine


here is the original smear of aluminum
IMG_4698.jpg

i have a tough deposit that is thick and stuck!
it is slowly being dissolved
IMG_4715.jpg

the smear on the other side of the oil port is completely dissolved
IMG_4716.jpg


there may be hope for the old crankshaft! :grin:

more to come!!!!
 
Update 5/15/21

everyday, for 17days, i have applied a water/lye solution to the smear
it has all but disappeared.
i figure in a couple days the smear should be completely removed

Before

IMG_4698.jpg


Currently
IMG_4728.jpg


the process is proving to be valuable!!!
 
nice! If you ever want to speed things up, warm up the lye to just below boiling. Be careful when you put the part in (violent bubbling) and do it outside or somewhere well ventilated as the fumes are NASTY. I use it to remove anodising or for giving a dull etched finished to aluminium and it's one of those times I take full precautions (no flip flops!).
 
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