rebuilding new nikasil motor

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Hi
I bought a motorbike brand new. It has a 4 stroke engine with nikasil lining. The first ride out of 220miles it used almost half a litre of oil, second ride was the similar. Oil consumption dropped to a rate between 500ml per 1000miles and 900ml per thousand miles, till about 1500miles. Up t this time I was running iin by the book, keeping rpm less than 7000rpm.

Once "run in" the bike went back to almost 2litres per 1000miles.

From the first time out I continually complained to the manufacturer, and at 1932miles they agree to inpsect it.

They found, carbonised pistons and damage to the crank.

These parts were replaced along with new piston rings.

My questions are,

1) how likely is it that the new rings will seal with Nikasil bores which have covered 2000miles?
2) Will it be as good as new?
3) Is there much chance engine power or longevity being compromised?

thanks in advance
 
As long as there is no damage to the cylinder, the new piston and rings should seat just fine. As far as your remaining questions, it truly depends on the quality of the work -
 
Nikasil is tough.
A fresh set of rings will seat just fine.

Any response from the manufacturer on what happened and why ? What sort of crank damage ?

With minimal miles on the engine did you find a hill and hit it in a high gear at low revs, WOT to get the rings to seat ?
Theory is that this gets high levels of combustion gasses into the ring grooves at low speed forcing the rings against the cylinder wall. Then you go back to running normally as per the manufacturers recommendation.
 
Right.
That crank damage is a whole new story.
Maybe you were just unlucky with a bad engine.
This is something that was not common even in the 1930s.
 
It will seat the rings just fine. I would ignore the OEM break in procedure. As you can see it did you no good! The go ahead and ride it like normal. I would recomend plenty of down shifting to get the engine breaking to lift the rings and keep them from sticking. I use Motuneusa's break in procedure on everything I own and have had nothing but great results doing it his way!
 
There is no need for a fast break in.
You'll get there either way.
Do you think there is a timer or something that only allows a narrow window of time for break in? A chemical change in the metals? Mythical 'glazing' [whatever that means]?
Normal driving puts plenty of pressure on the rings/bores.
It won't hurt to give full throttle here and there right away, but no need to beat the wee out of it immediately.
 
thanks for the response guys.

I am not sure I am getting the whole story either.

I found out today the cause of the oil usage was glazing to the bores not a valve stem oil seal I was as previously told.

I was told the marks on the crank were coincidental.

So back to the Nikasil bores. The manufacturers tech told me he busted the glaze with a fine grit paper and lubricating oil.

So back to the same old question. How likely is this to be as good as new, or should I just cut my losses and sell it on. Other option is to reject the bike, take them to court to get my money back.
 
They might have it "good as new" but it doesn't sound like "new" was all that "good".

There is nothing inherent that keeps new rings from sealing on a "used" nikasil bore, it's very common on motorcycles that last 20x longer than yours did. I'd be curious if the bore is the correct size for the piston and rings.
 
also, is it possible for bores to glaze up from brand new to 220 miles over one days use?
 
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