Knocking noise on 82 kz550 LTD C3

I saw that in the manual. Say i have the largest bearings currently installed.... Is there a chance i could machine down to the smallest size?

Otherwise, I'll actually get this engine apart and verify what i'm guessing right now. Anyone got a crank?

Much easier to look for a used motor. They used to come up often on craigslist. 10 years ago they were in the $50 range. Maybe more like $100 now. Rebuilding the bottom end will cost more than that, and then you'll still have to mess with the top end. At least I don't think you can pull the crank without taking apart the top end, but now I wonder.

where are you located?

No eBay APP ID and/or Cert ID defined in Kunena configuration
yikes. Rod and crank are done for.

On ebay they were around $500. But I found a motor for sale on eBay from a bike shop in ohio and they're willing to pull the engine apart and get send the crank/bearings for $200 shipped. I need to ask for the rod(s?) as well now and probably the secondary shaft chain as it has 20mm of play. The potential donor has 5k miles so it should be fairly healthy ( but i will confirm this with them).

I am in Rapid City, SD.

The timing chain is currently holding in the crank, so i will have to remove the cams to get enough slack to remove the pistons. I will end up pulling and verifying the pistons as there was a lot more than one bearing's worth of metal in the pan.

Questions:
-I tried to find the section on the bearings but its late and i'm struggling... I know you look at the numbers on the rod and crank and that's how you pick the bearing color. What is the reason for this variance? the crank journal size? rod end size? crank journals in the crankcase? What i'm trying to get at is: can i get all the bearings that came with that crank, put them in my block and rods and have proper tolerances? If it's the crank journals and not the block, it should work ok. All the rods are there in the donor so i could just swap my pistons to their rods

- is the listing I was looking at. Should be the same crank even though it's a shaft drive model.

so! the plan is to pull the crank, verify pistons, verify my transplant plan with you guys and then shoot a message back to the bike shop with what i need. thanks again for all the help!

No eBay APP ID and/or Cert ID defined in Kunena configurationNo eBay APP ID and/or Cert ID defined in Kunena configurationI really hate it that my presumption come true.
I am sorry that you have so much trouble with your engine..
For 200 Dollar and less you will get a complete engine here in Germany

This project just made an interesting turn... I found a kz650 motor from a 1979 kz650C C3 at a swap meet for $150 so i'm currently shoehorning that into my frame! It fits alright but the motor mounts are being reworked as the upper rear is about the only one that might work. Far as I can tell the sprocket is in the same location relative to the center of the motor so the goal is to get that motor in the center and verify the chain is lined up.

I had to transfer over a few things from the kz550 motor:
gear selector cover
ignition advancer
stator/flywheel (need to fab up an adapter plate)

The starter is missing as well but I got the kick start for now and the hope is to use the kz550 electronics/ignition. I'll probably start selling off the kz550 stuff once i get this running. I did put a quite a bit of time into cleaning up all of those parts so if anyone wants some clean kz550 engine parts... lemme know.

I like it!

Please take lots of photos and post them up here! We LOVE photos of other people's projects!

I would even go further and say why 650 and not 750 !?!?
I would go the 750 way.

Ahh yes will do Nessism. Would they be better in this thread or a new build log thread?

Yea i found that out when reasearch as well, it was said that 750 mounts are similar... maybe itll drop in to my 650 mounts? I was trying to keep it budget and I found a 650 not a 750 haha.