Motor Core Inspection for Rebuild

[Wilsonsk]

I got a parts motor from a friend of mine. Here is what I know:

1981 motor
Head and valve cover were both loose
1 piston was out of the motor
I found bits of the other piston when I removed the oil sump
The motor had been apart before that, lots of orange permatex remnants

I’m considering buying a 750 kit to rebuild it with. Given the nature of the piston failure, what is the process for inspecting everything? Obviously I’ll split the case, what do I check on the crank?

Thanks,

Steve

 

[gggGary]

Two cents; find a better core.
Too many gotchas lurking in what you have, should be able to find a GOOD core in MN for less than 200 and be WAY ahead of what you have now.

 

[Wilsonsk]

Thanks for the advice, any likelihood the crank would be a core for 277 phasing?

 

[Jim]

Thanks for the advice, any likelihood the crank would be a core for 277 phasing?

If you're gonna send the crank out to have the work done, replacing the bearings and connecting rods is usually part of the package. So long as it's not rusted or beat to hell it should work for a rephase.

 

[Wilsonsk]

gggGary, I went right past you to pick up my 76 xs650, it was in Hartford. Parked since 1997.

 

[gggGary]

gggGary, I went right past you to pick up my 76 xs650, it was in Hartford. Parked since 1997.

So YOU were the dog that got that 76 I was aging for the charity buy.
Ha ha ha.

 

[Wilsonsk]

If you're gonna send the crank out to have the work done, replacing the bearings and connecting rods is usually part of the package. So long as it's not rusted or beat to hell it should work for a rephase.

No rust, as far as I can see. I’m not dead set on the 277 rephase, but if I have a core crank that minimizes down time of my bike, I could send it off in a moment of weakness, I can use the cases and TCI on my engine, it’s running well on the points but I could still convert. The core motor was free.

 

[Wilsonsk]

So YOU were the dog that got that 76 I was aging for the charity buy.
Ha ha ha.

That’s the picture from the add. And one from today.

 

[atom4488]

That’s the picture from the add. And one from today.View attachment 247708View attachment 247709

Cleaned up pretty nice! Like the short front fender, pipes and gaiters.

 

[Wilsonsk]

Cleaned up pretty nice! Like the short front fender, pipes and gaiters.

I was surprised it cleaned up that well, there is a fair amount of rust from condensation all over it but I haven’t thoroughly cleaned it yet, just knocked the big chunks off. I’m going to replace the spokes with stainless over the winter, they are pretty rusty, seem to be structurally sound but look awful. I’ve been focused on getting it safe and reliable. I’m very pleased with how well it’s coming back to life

 

[Wilsonsk]

To kind of button this up, sounds like I should part this 1981 core motor out, should have good alternator and and TCI pick-up and I can clean and polish all of the engine covers and then swap them onto my motor. I may have a good crank core for phasing (not convinced I'm going to do that, rather do the 750 kit if I spend a little money, both if I spend a lot....).

I guess if my main objective is the 750 kit, if I have the other cases cleaned and polished, its maybe an addition day with the motor out of the bike?

Thoughts?

 

[nj1639]

Thoughts?
Save your TCI parts and pieces for yesself.

 

[Wilsonsk]

Thoughts?

Save your TCI parts and pieces for yesself.

That’s my plan, less down time if I can prep On spare parts. The case covers are all in better shape than mine anyway.