Tear motor down or try a new headgasket?

racerone

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I have a number of these motors for parts.---Memory tell me there are more than 3 screws on the lower cowling.---Possibly 4 and some pins , these covers come off quite easily.
 

sutor623

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I have a number of these motors for parts.---Memory tell me there are more than 3 screws on the lower cowling.---Possibly 4 and some pins , these covers come off quite easily.


Thanks Race you are right. There were 4 screws and it came right out. It looks like the hinge is on the exhaust housing, yet the bolts go all the way through to the powerhead.

EMD, thanks as well. I actually took the lower unit off to prevent me from bending the shift shaft. Why not?? Plus I just changed the waterpump a few months ago but Ill be darned if I dont inspect it before putting a newly rebuilt powerhead on there!!
 

sutor623

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Hinge ?---Cover bolts go right to the powerhead ??

Sorry I meant the hinge for the midsection. Got all the nuts/bolts out and sprayed the seat with PB blaster. Don't have a hoist so have to try and get it loose. She's really on there!!!' The cold sure don't help.
 

sutor623

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Guys I can NOT get this powehead to split off the exhaust housing. Even tried roping it up and putting the tractor bucket under it but I about pulled the boat off the trailer!!!
 

racerone

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List the fasteners that you have removed that hold the powerhead to the exhaust housing.
 

sutor623

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Got it loose, the gasket was just really hanging on!! How do I get the taper pin out to split the casings. Got all the bolts loose but not sure if I can just hammer the taper pin out? Is it actually tapered? I can hammer done one way but the cylinder prevents me from hammering the other direction.
 

racerone

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The taper pin is in fact tapered !-------It is inserted from the carburetor side.-----So it must be driven out towards where the carburetors were.----This job is done that way all the time.
 

sutor623

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Ok thanks I'll get some pics up tonight or tomorrow morning, should have this thing split
 

sutor623

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Any tips to getting this pin out? It is really in there and I cannot get enough force behind it to get it out. Very awkward angle. Pry bar slips off and any punch I try to out in it seems futile.....
 

racerone

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If you understand the concept of " thermal expansion " then this might be easy.-----Use heat to get this pin out.------Heat will open the hole in the block and the pin may fall out !!!
 

sutor623

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If you understand the concept of " thermal expansion " then this might be easy.-----Use heat to get this pin out.------Heat will open the hole in the block and the pin may fall out !!!


Oh yea I love the blue wrench. Just a little intimidated to use it on something soaked in fuel and oil!!!

I ended up getting the pin out. Had to make a long metal punch but got her out!! My next question is do I pry the bearing and head assemblies out or try to split the crankcase now? (Really wish my factory manual wasnt 35 miles away right now!!!!!!!!!!!!!!!!!!!) It really feels to me that I will need to apply heat to the crankcase to get it to split open. There really are no good pry spots. Been slapping at it with the rubber mallot with no resolve.....
 

sutor623

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I have heard to tap upward (with a rubber mallot) on the exposed portion of the crankshaft. Is this a good practice? Basically smack the part that the flywheel sets on??
 

racerone

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???----Again , these things fall apart when all the bolts are out.------How many fasteners are on your work bench?? --------------No heat required for this task !!
 

sutor623

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Okay. I have 4 small bolts from each side, and two large ones on each side (one is the allen head). I also have all of the fasteners off from both the top and bottom bearing plates, and the one taper pin.
 

racerone

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????----There are 6 large bolts in total !!!!!--------------Do you have the carburetors and reed valves off this motor ??
 

sutor623

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Oh okay that's is where the hang up is. I do have the reed boxes all off I remember seeing the two other bolts in there. You're the man!!

After the uva tech game I'll be on it!!
 

sutor623

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Ok so that was the hang up. Missed hose two bolts. Should I mark all of the rod caps with a sharp pencil so I get the alignment right or do I need a rod cap tool when I reinstall? I think all of the crank seals
And journals look good so i am going to continue to dig deeper.
 

sutor623

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Ok, got some pictures of the internals. The crank journals all look good. Cylinders 2-4 will be in great shape after a good hone. I believe that cylinder 1 will be good after a hone as well. Pistons all look good, aside from cylinder 1 which is damaged beyond repair. Needle bearings all look good with no signs of running too hot. Crankshaft sealing rings are all in tact, and it does not look like I spun a ring.

Still cant figure out where this debris in the intake port is coming from. Maybe its just part of the damaged piston.



But I believe it may have come from this bad casting here. This is cyl 1 crankcase and intake. Need to break that little piece off as it is a disaster waiting to happen.



Piston 1, clearly damaged down the skirt and just off the ring groove. There appears to be a depression in the upper ring on the exhaust side. It is very strange. Almost like the edges of the ring have been flattened some:



Can you see the depression in the ring? Maybe this is from the overheat that this motor endured at some point in its life?



Crankshaft:





Block:










 

sutor623

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You guys think I should hone out cylinder 1 and see if it gets the light scoring out? Or should I send the block out for boring? Don't have any machine shops nearby....
 
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