Piston Ring Service Life

What is the average (miles-travelled) service life for a set of new rings when properly installed in a Kawasaki 1000-1100 J-motor?

I guess it's like the old "how long is a piece of string" question. It's infinitely variable based on oil quality, the ways it's ridden, quality of air filter and how regularly it's changed, environment it's operated in etc etc etc 

My MTC G1135 Pistons and rings have traveled 25k miles.
The engine currently consumes 1qt. per 350 miles on average.
I use Rotella T4 15w40 exclusively, and change oil/filter every 3k miles.
I typically run the engine 5-7k rpms, and frequently tap the red zone when upshifting.

Cylinder compression is 160 psi x 4.  The piston crowns and spark plugs are dry.

Considering the miles and compression, might a cylinder hone and/or new oil rings help reduce the oil consumption?

daveo wrote:

My MTC G1135 Pistons and rings have traveled 25k miles.
The engine currently consumes 1qt. per 350 miles on average.
I use Rotella T4 15w40 exclusively, and change oil/filter every 3k miles.
I typically run the engine 5-7k rpms, and frequently tap the red zone when upshifting.

Cylinder compression is 160 psi x 4.  The piston crowns and spark plugs are dry.

Considering the miles and compression, might a cylinder hone and/or new oil rings help reduce the oil consumption?

Only my opinion but that does seem a little excessive (I will leave the guys who rack up miles on these bikes to share their consumption rates) compression looks good

• How much oil did it use when it had done 5000mls
• Is there adequate crankcase ventilation?

PS: don't forget with new rings the oil consumption will increase for a few thousand miles until they have bedded in. With clean plugs and pistons I'm not sure it warrants the time and expense to hone and re-ring (as I say just my opinion)

Excess consumption.  20W-50 may slow consumption, but I doubt it will solve the problem.  

I would expect the cylinders to be fine at 25k miles, and your compression seems to back that up.  The oil ring is the lowest one of the three, while the upper ones are for compression, so you may still have a problem.  It might be plugged drain holes in the piston groove for the oil rings.  Or it might be valve seals allowing oil into the cylinders when you are parked.  You didn't mention if you have a smoker.  How is the exhaust?

Did you use the Rotella T4 to break in the rings to the cylinder?
Did you hone the cylinders when you installed the new rings?

You could also send your oil in for analysis and look at the oxidation value.

Rotella T4 since initial fire-up in 2019 when the MTC kit and cylinders were professionally prepped by Pit Stop Performance.

The cylinder head got a valve job and mild porting in 2021, and new Viton seals, just under 14k. miles ago...still beauteous.

Oil consumption has been a noticeable steady progression, same for the previous top end done in 2015.

Always wound up and rode like she was stolen...
 



...til yesterday.

The pistons are considered racing pistons. With that I would expect it to use oil. RIDING THE PISS OUT OF IT   would make it use more. If it were stock with 8-9/1it would be easier on oil and not run so hot. Are there service bulletins on this issue? Back in the day the 1000's were burning a lot of oil new and KHI said it was normal until they were made to fix it. Turns out it was steel valve guides so they went back to the bronze ones and they went back to normal. That was in stock form. I would like to know what the average would be on the higher compression builds. As it is my 1075 uses very little oil though I can see traces of it on the plugs. 
Steve