Time for a ring change

[gadgetman]

What are the first signs that the piston rings are getting tired?

[sean brady scooters]

usually a few more kicks to start................and harder ones............

[soullad]

Starting from cold you probably won't notice it at first but l;ike Sean says a warm restart will take more kicks than normal.
You might notice more spitback thru the carb, with a slight drop in mpg.
On the road you will probably feel that that it has lost its "sparkle" and is sluggish to respond to the throttle. Any kind of load exerted on the engine, such as hard accelerating will highlight it the most and in extreme cases it will struggle to reach top rpms.
Good opportunity to give the top end a check and make sure it was only high mileage that led to the ring wear!

[gadgetman]

Starts first time everytime and revs out in 4th at 8,000rpm ( rev counter fitted ), as for a drop in performance I can't say weather it has dropped or not but then it would have been at a steady slow rate
What got me thinking is that it does rev higher than it has previously but chokes up a little more than it used to do when left idling for example at traffic lights . Plus compared to all the other scoots I've tried it kicks over with seemingly a lot less compression and it's done quite a few miles at quite high rpm
Mugello 186
Lowered gearing 16 x 47 early Li 125 box
ScootRs exhaust
DellOrto Ph 30mm carb
Ram air filter
approx 8,000 miles on full synthetic Castrol
Could it be that the engine has just freed up hence the higher revs OR is it coming to it's end ??

[soullad]

Starts first time everytime and revs out in 4th at 8,000rpm ( rev counter fitted ), as for a drop in performance I can't say weather it has dropped or not but then it would have been at a steady slow rate
What got me thinking is that it does rev higher than it has previously but chokes up a little more than it used to do when left idling for example at traffic lights . Plus compared to all the other scoots I've tried it kicks over with seemingly a lot less compression and it's done quite a few miles at quite high rpm
Mugello 186
Lowered gearing 16 x 47 early Li 125 box
ScootRs exhaust
DellOrto Ph 30mm carb
Ram air filter
approx 8,000 miles on full synthetic Castrol
Could it be that the engine has just freed up hence the higher revs OR is it coming to it's end ??

Aside form the slight idle issue which could just be jet size / airscrew or even plug choice it sounds fine.........if it still niggles away at you why not take a look thou and set your mind at rest?
The performance drop issue is an interesting one. I often hear folk say that their engine was never as quick as when it was first built etc but thats probably because they have since got used to it!

[156 D]

Starts first time everytime and revs out in 4th at 8,000rpm ( rev counter fitted ), as for a drop in performance I can't say weather it has dropped or not but then it would have been at a steady slow rate
What got me thinking is that it does rev higher than it has previously but chokes up a little more than it used to do when left idling for example at traffic lights . Plus compared to all the other scoots I've tried it kicks over with seemingly a lot less compression and it's done quite a few miles at quite high rpm
Mugello 186
Lowered gearing 16 x 47 early Li 125 box
ScootRs exhaust
DellOrto Ph 30mm carb
Ram air filter
approx 8,000 miles on full synthetic Castrol
Could it be that the engine has just freed up hence the higher revs OR is it coming to it's end ??

...........i would of thought the way you would first notice tired rings as you put it, would be lower resistance to the kickstart (compression is less) and when climbing hills (probably in a lower gear) the starting and performance i would think just the same although i do believe they go better because of less friction, as they suck in just as much fuel as when new........i have owned some quick performing engines in cars and bikes in my time and have had my share of blow ups .......usually with a worn engine, when on song and the performance going exceptionally well to what it ever has done, the engine will just suddenly let go and bang...