I have a 620 and have some problems, maybe the pulley side main is out .
I bought this "as is", at an auction.
I changed the oil and dug out the crankcase before adding new oil. In the bottom were these little steel bits. I know bits and what broken out pieces look like. They do not have the look of broken out appearance. That look i am familiar with, has a mating type surface of a fractured look. These are smooth. They are not concave as a piston ring would look, not fractured like a gear tooth would appear. They are like 1/8" diameter by 3/8" long.
Being new to posting here, I do not see where to add pictures..I have 3 videos of the damage.
The next debacle is that there was an amount of brass chips all around the top part of the main bearing housing, above the crankshaft. The entire concave channel had this. These are little chips like. Also there was a strip almost like shim stock, a very thin piece of brass. Half an inch by 3 inches.
Next I measured the crank play-lift. I also need to set the endplay, advise?
To check crank movement, I put a block under the side of the pulley with a pry bar lifted the pulley. And with an indicator on the crank shaft nearest the bearing housing. The crank rose up .004.
The pulley near the frame side would rise .017. Subtract the crank rise, means it moved about .013.
I know someone will say you can't check the crank with the pulley on, but the measurement on the crank side of the bearing should be accurate, as the pulley rdes on the crankshaft. It would surely be a little different on the out side of the housing and I am working on pulling the pulley.
I was just hoping someone might comment on a measurement of vertical movement on a crankshaft. I read and under stand there is a clearance in the bushing type bearings. That should result in small movement of the crankshaft. How much movement is tolerable is the question.
I understand the only way to know is to tear it all down. Just looking for a reference. The people I know who had a 620 with loose bearings said they could pick up the pulley and it would be very loose and still was running. I know what main bearing rumble sounds like, but have not fired this one up yet.
I am into it right, so can afford to repair it and do all of my own work. .
Thanks for any insights. Matt
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I bought this "as is", at an auction.
I changed the oil and dug out the crankcase before adding new oil. In the bottom were these little steel bits. I know bits and what broken out pieces look like. They do not have the look of broken out appearance. That look i am familiar with, has a mating type surface of a fractured look. These are smooth. They are not concave as a piston ring would look, not fractured like a gear tooth would appear. They are like 1/8" diameter by 3/8" long.
Being new to posting here, I do not see where to add pictures..I have 3 videos of the damage.
The next debacle is that there was an amount of brass chips all around the top part of the main bearing housing, above the crankshaft. The entire concave channel had this. These are little chips like. Also there was a strip almost like shim stock, a very thin piece of brass. Half an inch by 3 inches.
Next I measured the crank play-lift. I also need to set the endplay, advise?
To check crank movement, I put a block under the side of the pulley with a pry bar lifted the pulley. And with an indicator on the crank shaft nearest the bearing housing. The crank rose up .004.
The pulley near the frame side would rise .017. Subtract the crank rise, means it moved about .013.
I know someone will say you can't check the crank with the pulley on, but the measurement on the crank side of the bearing should be accurate, as the pulley rdes on the crankshaft. It would surely be a little different on the out side of the housing and I am working on pulling the pulley.
I was just hoping someone might comment on a measurement of vertical movement on a crankshaft. I read and under stand there is a clearance in the bushing type bearings. That should result in small movement of the crankshaft. How much movement is tolerable is the question.
I understand the only way to know is to tear it all down. Just looking for a reference. The people I know who had a 620 with loose bearings said they could pick up the pulley and it would be very loose and still was running. I know what main bearing rumble sounds like, but have not fired this one up yet.
I am into it right, so can afford to repair it and do all of my own work. .
Thanks for any insights. Matt
[/img:1829ad0e50][/b]
