RS34 Tuning Assistance Please

daveo wrote:

Taken minutes apart, after the bike was parked a couple days.

I suspect a cylinder #3 issue is the oil consumption culprit, but what steps may be necessary to remedy the situation?

Will a top-end tear down ultimately be required to get at the problem?

🧐


Meanwhile, she's running great!!!

I would suspect the most likely culprit would either a damaged valve stem seal or an "oil scraper ring" issue on #3 piston (this wouldn't show from a compression test which I know is excellent on this motor) Before you dive in too deep it's worth checking that your crankcase breather is not restricted

Will pull the breather cover and check this morning...

I wonder if that cylinder sleeve had an inherent weakness, after sitting in a warehouse on a pallet for thirty some-odd years.  Image below:



That concern was brought up with the engine shop before the cylinders had pistons fitted...was NOT considered an issue, and the work was performed.
 

What was it like after re-bore and was the ugly part below the oil rings at BDC ?

That's a pretty deep looking pitted ring there. Did they get all that out after 'BORING", you did bore them didn't you? That's the battle selecting "oversize" piston sets. While the others maybe didn't have as much damage? Trying to compensate for removal of that particular #3 i would of just sourced a better STD liner example.  

Wasn't a concern with Jay/MRE, who was hired to do the job and provide the Wiseco kit.

On receipt of the finished cylinder block I could not see any remnant corrosion, so I assembled without further thought.





   

Others below...

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They don’t look bad to be fair 

Great assessment Guy.  It pretty much rules out the cylinder wall as a potential cause...thank you!

Other than a bad valve seal, could aligned oil ring gaps create such an oil issue?
 

Yes, If the oil rings aren’t fitted correctly they will allow oil to get past - was it you that fitted a sponge filter in the breaker housing ?

Those liners look awfully thin. Does it say 1.890 on them? What size are they now? 

1.089 L.  72.5mm bored to 75mm

The Wiseco K1172 is the only piston kit specifically made for the ZX1100A model engine/crank with 18mm wrist pins...that doesn't require re-sleeving.

😎

There is no breather obstruction, and the air box is clean. 


 
The space beneath the breather cover is clean also, and has no filter element installed...
The original motor had a Ram filter media strip installed to minimize oil being blown into the air box.
To my surprise it actually worked!

🤓

A brief listen along follows...riding in the tool tray beneath the seat:

photos.app.goo.gl/SpxNzNaSZzY7rjTU8

Cyl. #3 an hour after that:


Fuel screw was turned in slightly...dry piston, and plug looks better...for now, go figure.



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