How many miles is too many for a used bike?

I'm excited to be getting into riding, and I've narrowed my search down to a couple KZ's. There's a 1977 KZ400 with 16k miles for $1200, and a 1978 KZ750 with almost 40k miles for $800. Both are clean and generally well maintained.

I'd prefer the 750, but the miles are kind of scaring me. Should I be worried or can these go 100k miles with the proper maintenance?

Sorry, I realize it's impossible to say without seeing the bike, but if anybody has any experience with these living forever or dying early I'd love to hear about it. I guess I'm just trying to get a feel for the reputation these bikes have.

Thanks!!!

How long is a piece of string? You are looking at two old bikes they could both be gems or complete piles of crap. Do you know much about motorcycling ? If not take someone along who does to guage condition of each bike.

The 750 will have the better performance but will be more costly if it needs repairs/ spares due to the extra cylinders and disc brakes .

40k is no excessive for the age of the bike but that could be about to become a costly bike if you need to get new brake discs or get carbs rebuilt or a new exhaust.

Keep us informed of your decision

How well the bike has been maintained, whether or not the bike is stock, and whether or not the bike has been ridden on a regular basis will have a greater impact on it than 16K or 40k miles. A bike could have less than 1,000 miles on it, but if it hasn't been run in 30+ years and has been sitting behind the barn it may need more than a bike with 80,000 miles that has been well maintained and ridden on a regular basis. In addition, a bike that has had previous owners over-rev the engine or modify stuff may be junk compared to a bike that has not been abused or a stock bike that has all its parts. As an example, if someone has removed the air filtration from the carbs thinking (erroneously) that this would improve performance and ridden the bike so that dust and grit have been sucked into the cylinders the rings & cylinder walls are probably shot. Likewise, if someone has cut the exhaust system and/or removed the stock air box they may have run the bike very lean and caused internal problems due to overheating.

The bottom line is that the mileage on either of those bikes is not excessive, so what really needs to be determined is the history and condition of the bikes. How many owners, and how did the owners treat the bikes means more than the mileage. It would help if you could post several pictures of each bike so folks here can make observations as to their general condition. Ed

Thanks so much for your words of wisdom! I've been reading a ton, but it's better to hear it from actual people.

I'm going with a 1978 KZ750. The suspension is smooth, the tank is clean, the tires will get through this season at least, and the brakes stopped it. There's a very slow oil leak, the seller thinks a set of gaskets would take care of that. I have no reason to disagree, and for $800 I figure I'll be getting my hands dirty on a few things. That's why I'm getting it after all!

I'll be stalking the forums for info from now on

That's a great looking bike.

Welcome to the forums.

This was too many miles! :whistle: Actually the bike was taken care of until the balance shaft drive sprocket wore out and the chain skipped a few teeth. Yamaha didn't think anyone would put that many miles on a bike made in 1973!

Everyone else said what needed to be said. It all depends on how it was taken care of. I don't look at mileage when I am buying something because it's not what kills the bike/car.
I bought (whopping $1) another 1974 Yamaha TX500 with 58,000 miles. It needed valve stem seals, points, one carburetor, and a seat. Bike is perfect and I would trust it on any trip.

Looks like you got a great bike I picked my '78 650 up for $800 with 40 thousand KM on it. Had low compression, so I thought a set of rings and that should be good. Upon further inspection, I found that the previous owner hadn't maintained it as well as they should have, and the valve seats were worn badly. After a rebore and complete valve job, runs like a top.

All in all, looks like you got a good bike for the cost

Regarding the slow oil leak - if it appears to be coming from the area where the tachometer cable connects to the cylinder head it is a common minor problem and VERY easy to fix. Ed

if it was kz750 four with 40K i'd say no issues but not so for the 750B twin. were never were as reliable as fours, vibrate quite a bit, tall and not that great handling, at least not compared to the fours

I might piss some 750b owners, so remember it's just IMHO,

try find a kz650-700-750

The bike previous to what I own now was a 76 KZ400 twin, not the fastest thing on the block by far, but changing out the front sprocket from a 15 to 16 tooth, netted me a solid 78 mpg under most all highway conditions, whether riding alone or with the wife on the back. Although most articles I read said it was designed as a throwaway bike at around 20 k miles, I sold mine still running at 40k miles. There were no cam bearings for the single overhead cam on the engine and that cam rode on the cast aluminum of the head, eventually wearing excessive clearance top to bottom in that cast, and I had modify the cam chain tensioner to take up the excessive slack created by the wear. I doubt my inline 4 will ever get the kind of gas mileage that twin got.