Oil Analysis....Aluminum Shavings

[Wez_]

Hello forum. So my 82 Nighthawk has sat for many years in a barn. Finally I got my hands on it and rebuilt the top end and carbs. I verified everything as best as I could with the anxiousness of hearing this baby run looming over me. With that being said, after hearing her roar, I drained the oil only to find aluminum throughout the last few millileters of oil. The heads were blasted and valves ground. The oil pump screen was horrible with debris when I had the pan off and this debris "COULD" be from a prior condition now rectified after my head work (unlikely but possible).

At any rate, the engine is now removed from the frame again and I am curious where I should be looking for mistakes.

First thing that comes to mind is chain slack. Just read in another forum, someone blowing a hole in the block due to the chain rubbing. This could be my issue as well as the chain tension procedure on a motorcycle is new to me. Can someone please give me a fool proof chain tension procedure?



I hope this project is still salvageable.

 

[Davidson750]

Let me understand... you had head work done.. then you ran the motor, when did you notice the screen intake being clogged?..after or before?... the pan and pump should have came off at the same time and have should have been cleaned..fine metal shavings are not uncommon in a bike of that age depending on the service record remember it is metal against metal and there will be wear

 

[SenseAmidMadness]

That's a lot of aluminum.

When you did that top-end rebuild, did you by any chance check the condition of the oil galley where the primary cam chain runs from the crank to the exhaust camshaft?

On my 1980, before I did a top-end, the chain had gotten so slack and the tensioner was working so poorly that the chain ate a groove into the head. That aluminum ended up all over inside the oil pan and the first drain looked almost exactly like yours.

I'd run a magnet through that. If there's a lot of magnetic stuff there, something worse than cam chain rub is going on.

 

[Davidson750]

Looks like ring material...what did the oil filter itself look like? It's an overhead cam motor so if any metal that started at the top would have to make its way all the way to the bottom(past the pistons).. so it's either going to go out the exhaust or back up into the head, did you pull your valve cover off and see if there's any metal up top, and pull your line that delivers the oil to the top of the head and see what that looks like

 

[Davidson750]

That's the pickup I did on a rebuild a few years ago cb750f..and still managed to circulate oil...