Motor Life Expectancy

Hi,

I reckon the cam chains last about 30 - 40,000k's...you can be lucky...or unlucky with the valve stem seals...it will eventually start to use a bit of oil...put up with it using oil for as long as you want to before doing something.

At 17,000 miles (about 27,400k's or so)...you'd be looking at changing the cam chain in a while. Wait until you're close to running out of cam chain adjustment...I wouldn't really look at anything else unless it is using oil, then do the top end. That is rings (...have the bore measured first) re-seat the valves unless you need to replace one or so, valve stem seals etc...while it is down look at the cam and followers for excess wear..shouldn't be a problem if you change the oil regularly...

The bottom end is almost bullet proof and will last well beyond 60,000 miles easily. I pulled one of mine to bits at about 100,000 k's and the con-rod was still fine and so were all of the bearings.

When you do eventually do the crank make sure to clean out the sludge trap! You need to remove an allen grub screw from one of the crank flywheels first. It gets full of centrifugally compacted dirt and stuff.

SR

In the ten years I abused my 79 SR500 with lots of full throttle accelerations and shifts near red-line, I found that every 15,000 miles or so it started using oil. I just did a top end job and it was good for another 15 k miles. Never had to work on the bottom end. I found the bike easy and cheap to rebuild. 43k miles on the bike before I sold to another SR rider who wanted a spare.