KZ750 noob engine disassembly - what work to do?

could i be soo cheeky and ask u to post a link to the one you purchased. lol.

im not sure which one to get size wise or grit? any idea?

here is the seller I got it from, mine was 220 or 240 grit I forget, but it was perfect for re-ringing which is what I did. My bore size is much larger than the one I linked, but you need to look at what your bore diameter is and get a 240 grit hone which has your bore size within it's honing range.

cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll...tn%3D2&category=6755

Yes, 9am53, your thread is a veritable gold mine. I recognized the picture of your thumb's up with your favorite tool in the background. My favorite tool, too.

I didn't get a hone because I figured the shop would charge me $30 for that particular piece of work, and it's not a tool I'll use often. I have serious space constraints.

Thanks so much for your help. Your thread is super helpful, and I'm sure it's funny (annoying) reading someone else going through basically the same stuff and not reading the relevant entries from previous threads but, for what it's worth, I assure you I've tried..

Here's the "after" picture. I put in a couple hours of scraping time. Cleaned up pretty well. Still some spots look discolored, but I think that if I kept working on them I'd start taking metal off.

that's perfect, mine must have been really caked on, or maybe it was that I was doing it in the middle of december in -20*C weather...who knows...

hello all i have measured my bores 1 through 4 and they are

cyl 1 51.87mm
cyl 2 51.86mm
cyl 3 51.87mm
cyl 4 51.83mm

this was from the top. i will have to have them honed at a special place and get the pistons made by them if i can. lol

If you really can't track down any rings, and Z1enterprises can't either, maybe it wouldn't be a bad idea to bore your block out to a 550... I think they have a bore of 52.4 mm...that way you can just get a set of decent 550 pistons and rings are available for them np.

9am53 wrote:

If you really can't track down any rings, and Z1enterprises can't either, maybe it wouldn't be a bad idea to bore your block out to a 550... I think they have a bore of 52.4 mm...that way you can just get a set of decent 550 pistons and rings are available for them np.

what about the hight deck of the KZ550 pistons?

as teh new pistons could change the stroke?

i thought the rods would be shorter on teh 400 thus the pistons are pretty much teh same in hight

i have just measured and had a bike shop measure my actual pistons, they are just over 52mm thats is the actually piston itself

Nah, 9am53, that stuff was HARD. I used floppy razor blades that I got at an art store. The vertical scraping method worked very well, and I bent them (within elastic limits!) into the letter U for scraping around the bolts.

In search of the piston ring shard, I took the engine out, flipped it over, spun the cranks a whole bunch, shook it at a few angles... nothing came out. I don't know where it went, but I'm pretty sure at this point that it's not in the engine.

Different questions now: the O rings on my oil cooler were these little blue things. I used the microfiche at mbsween's KZ750 site to identify them at 670b2012. Called a Kawi dealer and they want to sell me two of them for $6. Any reason I shouldn't bike down to the hardware store and get a couple 12mm O rings there instead?

What type of oil did you use? I know there's tons of discussion on this subject, but I gotta say, the conventional Shell Rotella sounds appealing. It's cheap and there are people who swear by it for old bikes. I did a run of synthetic, like an idiot (the leak that followed is why my bike is in pieces), but now that I've taken it all down, I'm gonna keep it conventional.