Rebuild or Part Out GS1000 Engine

[JTGS850GL]

I've started the disassembly of the Frankenstein bike for part out and decided to pull the top end to see what's there. Found some very disturbing things that seem to relate to a loss of oil pressure. I tried to run the engine after the basic maintenance (Oil change, Carbs rebuilt and valves adjusted). Once started I heard a very pronounced ringing/clanking sound coming from the top end. I pulled the top end and found this:

Cam saddle and seats on A and C were badly scored:

Saddles B and D were much better:

Rod #3 was obviously over heated:

The other rods looked like this:

Here's the #3 piston pin:

Cylinder #3 has some slight aluminum scoring but not so much that a honing wouldn't take out.

Now I'm at a decision point.... Should I rebuild or just part out this engine and pick up a new spare? Any input would be greatly appreciated.

 

[posplayr]

I would say it is a gamble, so unless you value your time and energy low get another.

I had a moped I bought last year. It had lost compression (I picked it up for $150) and as turned out had a rod end that had gotten very hot as shown. I finally got a new piston/cylinder/pin (moped stuff is very cheap) to fit very nicely and the moped started right up. I ran it for about 4 months and it ran great. Then suddenly died.

 

[JTGS850GL]

Ya, I'm leaning toward parting out the engine. I tried to fit a piston pin from one of the other pistons into the rod that's darkened and it wont go in. It goes into the other three easily but not on the one that's darkened. My guess is the rod small end would need to be reworked on that rod at the very least.

Too bad... Anyone need some GS1000 engine parts?

 

[rapidray]

Sorry but that rod is JUNK! When they get that much heat in them, they are a throw away.
Ray.

 

[posplayr]

Ya, I'm leaning toward parting out the engine. I tried to fit a piston pin from one of the other pistons into the rod that's darkened and it wont go in. It goes into the other three easily but not on the one that's darkened. My guess is the rod small end would need to be reworked on that rod at the very least.

Too bad... Anyone need some GS1000 engine parts?

This is a picture of the rod end I reconditioned "insitu", I used a socket that was just smallerr than the pin and 800 grit sand paper. Kept working it till the pin would slide in easily.

I polished he old pin and use it at first still it would fit, then I moved to the new pin to avoid scouring it up.

lasted for a while (150 cc)