Spare engine questions

I’ve seen an engine pop up about an hour and a half away from my location that claims to be from a 1980 KZ750 4 cylinder, however it bears little resemblance to my original 1981 KZ750 engine. i would be interested in picking this engine up as a spare as I currently have no idea how many miles are on my engine and wouldn’t mind to have a spare sitting idle by ready to go in the event this one grenades. My issue in picking it up is $350 is a solid chunk of change for a motor/transmission that claims to only have 5k miles on it but it also claims to be a 1980 but appears more like a ZR7 engine. I’ll attach the eBay link and item number and I would love to have some more experienced eyes look at it and see if it would be a direct drop in or not. 
Ebay
115492741889

Serial number is kz750N. It’s from a Spectre. 82-83 maybe. That’s about all I can tell you

It's not a ZR7 engine - they don't have the mounts at the bottom of the engine like this one does. The side cover matches a KZ750 spectre cover. There's also what looks like a kz in the background of the photos, likely the bike it came from

They could have got an old corroded kz750 spectre, given the engine a quick rattle-can job, and are selling it. How they know it 'only has 5000 miles on it' is questionable. My kz750 has only 14k on the odometer, but the engine has done 114k. A quick paint can be used to hide the fact that it's been sitting outside for a long time.

It might also have been a perfectly servicable engine which they thought needed a clean-up with a splash of paint. Personally I'd want to check under the covers and a compression test before handing over the money. Ask a few questions - it may have been painted and used for 5000 miles and now they're putting in a bigger engine or something - wouldn't hurt to ask and see if there's a reasonable story behind it.

Edit: just checked the pictures again. The spark plugs are painted and ports are blocked with cloth, it's just been painted. Like I said, paint can cover a multitude of sins, and the only reason you paint something before you sell it is to make it look better, implying it looked pretty bad to start with. A quickly painted engine is not going to stay looking good for long. But the engine itself may well be mechanically fine, it's hard to say.

I agree with you Irish, I also noticed the paint was covering literally everything, spark plugs included. It doesn’t give me lots of hope. I doubt the owners would allow me to come compression test it prior to an eBay bidding. Possibly get my money back with the eBay guarantee but with local pickup it could get questionable. 

Also Mikaw, thank you for the serial number decode, which could mean the engine was swapped into a 1980 KZ, and could be getting swapped out now that something has gone wrong with it. 

Just wanna chime in that it's almost definitely not a Spectre engine. No bevel gearbox for the driveshaft, wrong alternator/pickup covers, chain drive left side cover.

According to the information I have, that engine number makes that a 1983 KZ750 F1, shaft drive LTD engine. Evidently converted to chain drive. The KZ750NE series engines were used in both the LTD and Spectre models.

The chain drive cover is not even bolted on, so there is no telling what might be under it. Sketchy indeed. 

wrote:

According to the information I have, that engine number makes that a 1983 KZ750 F1, shaft drive LTD engine. Evidently converted to chain drive. The KZ750NE series engines were used in both the LTD and Spectre models.

The chain drive cover is not even bolted on, so there is no telling what might be under it. Sketchy indeed. 

Definitely a case of "walk away" 

I’m thinking the same thing here Wookie, there’s better stuff to waste $350 on. Thanks to everyone for your input here!