TOPIC:

after a good cleaning i saw this color mark on the bearings for the crank. to mee is like BLUE, but manual talk about black yellow or green..
it is supposed to be green?
some pic after clen

to me they looks good, i havent measured yet.

this is the one of the rod broken on the crank, this is bad

the crank look in this condition in all bearings seats

i found on ebay a good used crank with rod and bearings too. i think to buy it, look the color of the shells i will receive..if it's the same color , can i use mine shells with the ''new'' crank?
thank you.

Your cylinder damage looks like it's limited to the sleeve. They press in/out and can be replaced. I know they are readily available for the bigger KZ's from aftermarket suppliers. Check LASleeve or Wiseco for the 550. I'd do a through inspection of the cylinder block and then compare the cost between a replacement sleeve vs. a used cylinder block. There will be additional cost for the machine work required to bore and deck the sleeve. Then again, the used cylinder may require some machine work as well.

Yes, you can replace sleeves. The cost is about 3X the amount of purchasing a clean used cylinder though.

Hopefully there is time to search and find a good low mileage crank and cylinder. Before purchasing parts like these it's best to contact the seller and get their confirmation as to the bikes mileage and the condition of the parts. A lot of crap sellers misrepresent stuff but if you get a confirmation about the condition that will help hold them accountable. Scuffs and rust in the cylinders for example.

I've rebuilt three different engines such as this one by purchasing replacement parts on ebay. Had a couple of rows with the sellers on part condition but ebay will protect you if it comes to that. In each case I was able to find cylinder/piston sets from engines with about 15k miles so wear wasn't a big concern.

I got the "new" cylinders and crank from eBay. I had the cylinders honed in a machine shop , i got the crank bearing inserti Also and they are merked as mine. I replaced them with the new ones. They was in greater shape than mine. No scratch. All seems good.
I Aldo ordered new OEM head basket. I letto you know what happen after the first cold compression test.
My only question is HOW TO re-torque the head down after first running.
When engine is cold again i have to loose ALL THE BOLTS? or i should do it one by one?

shamal wrote: I got the "new" cylinders and crank from eBay. I had the cylinders honed in a machine shop , i got the crank bearing inserti Also and they are merked as mine. I replaced them with the new ones. They was in greater shape than mine. No scratch. All seems good.
I Aldo ordered new OEM head basket. I letto you know what happen after the first cold compression test.
My only question is HOW TO re-torque the head down after first running.
When engine is cold again i have to loose ALL THE BOLTS? or i should do it one by one?

Be sure to replace the valve stem seals while the head is off. And lap the valves (at minimum).

After a few hundred miles you need to retorque the head (cold). Back off each nut just enough to assure it's not binding (about 1/4 turn) and then tighten the nut from there. Do one at a time starting from #1 till the last (can't remember the number).

Nessism wrote:

shamal wrote: I got the "new" cylinders and crank from eBay. I had the cylinders honed in a machine shop , i got the crank bearing inserti Also and they are merked as mine. I replaced them with the new ones. They was in greater shape than mine. No scratch. All seems good.
I Aldo ordered new OEM head basket. I letto you know what happen after the first cold compression test.
My only question is HOW TO re-torque the head down after first running.
When engine is cold again i have to loose ALL THE BOLTS? or i should do it one by one?

Be sure to replace the valve stem seals while the head is off. And lap the valves (at minimum).

After a few hundred miles you need to retorque the head (cold). Back off each nut just enough to assure it's not binding (about 1/4 turn) and then tighten the nut from there. Do one at a time starting from #1 till the last (can't remember the number).

OK today i was able to restart the engine. The spare crank works very well. The engine is quiet and responsive. No overheat no oil leaks.
Thanks to all for the help and the support!
Then only one thing to understand: how this happened?
I can say it was Not fault of oil pressure issue. The rod was at all oiled and i saw no signs of seizure/overheat.
How a rod cap can be loose if no one touch it?
I wonder if someone had a similar experience...

Did you torque them to spec?
Steve

If you talk about the old crank , no. I didnt touch the rod.
I did new pistons rings, machined cylinders, valve job, new gaskets (all) new valves stem seals, new primary bearings. Carb rebuild, new coils.
Then disaster.
Now seems really fine.
I want just to understand what happened..

The PO may have been in there.
Steve

shamal wrote: Then only one thing to understand: how this happened?
I can say it was Not fault of oil pressure issue. The rod was at all oiled and i saw no signs of seizure/overheat.
How a rod cap can be loose if no one touch it?
I wonder if someone had a similar experience...

Good job getting the engine running well again.

I'm not sure why the 550's tend to spin rod bearings, I only know it's not overly unsual. I found this out while researching a purchase a while back. It's strange because the oil pump is common to some larger bikes so you would think there is enough capacity.

What about oil adiator air bleeding? I had the engine totally dry for the rebuild, so the oil line from the radiator was empty too.
Yesterday when i got the bike running again i loose with engine running one of the radiator bolts .
I saw a bit of oil coming, so i re thightened it..
There is something i dont know?

I prime my cooler but it would fill up on it's own. I'd test the pressure before I rode it for long.
Steve