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[grc]

Any chance one umbrella assembly is installed upside down?  It's easy to do with the latest version of umbrella breather assemblies...

 

Jerry

[Chains]

Same thought process here something upside down. Seen it happen before.

[grc]

Well I would check piston to bore clearance first off. Good piston or bad if this spec is off you will have issue. I would think that there is more going on then that brand of piston.  If that oil rail was bent I would think that there is cylinder damage and the rail once bent cannot be re used.

One thing I do see is that the oil ring support rail is not in the picture. If you did not install the rail it will cause ring flutter and the oil rail will pop out. Here is the instructions I pulled of KB site. 

https://www.uempistons.com/installation_instructions/motorcycle_installation.pdf

Good luck

I also don't see the spacer (support rail) that should be present when the piston pin bore extends into the oil ring groove.  Without the spacer the lower rail of the oil ring can do the same thing again.  Or am I just not seeing something correctly?

Jerry

[johnsachs]

Jerry nailed it. (Ring walk). No support rail (or oil ring rail). Same deal happens to women with no bra. Stuff hangs.
John

[Fired00d]

Jerry nailed it. (Ring walk). No support rail (or oil ring rail). Same deal happens to women with no bra. Stuff hangs.
John

 
Ride Safe,
Fired00d
 

[GMR-PERFORMANCE]

Thats what I posted up first go round .. nothing back from the OP?? I have to wonder if maybe they never came in the kit ??

[TorqueInc]

what sorta nutter would design a piston with that tall of a compression height....with a damn support ring...

[Rooster]

Me thinks dood had a vision

[bbsiding]

All problems solved  oil support ring not installed   Never had them  rear breather umbrella was upside down   New pistons   Tossed the KBs  flipped the breather over    Runs like a top   Gonna need a Clutch   Thanks to all

[deldago]

All problems solved  oil support ring not installed   Never had them  rear breather umbrella was upside down   New pistons   Tossed the KBs  flipped the breather over    Runs like a top   Gonna need a Clutch   Thanks to all

Glad to hear you got it running!

[Snakebyte]

Glad to hear also.
 

[GMR-PERFORMANCE]

Glad you got it taken care of. sorry that you swapped pistons nothing wrong with the ones you had. They do work ..

[johnsachs]

Glad you got it taken care of. sorry that you swapped pistons nothing wrong with the ones you had. They do work ..

I agree with Steve above.
Actually, the latest design KB hyper pistons don't use a support rail, as the wrist pin doesn't get involved with the oil ring groove.  I discovered this today as I was setting up to turn a '96" into a 103". ( the pictured ones needed the rail).
If the bore/hone work is done correctly, and the rings are squared in the bore, and then gapped to the recommended gap, you should have NO problems.    Problems arise when the bore and/or hone work along with ring gap is not right. 
John
Oh, Spirolox wrist pin locks........ BEST thing since sliced bread. Extremely safe, and foolproof. 

[bbsiding]

Thanks for all the help   Anyone want a set of KBs 95" std no rings  oil rings bent and broke a comp ring on disassembly  also wadded the spiral keepers  Hate em  Who thought that up   Any takers?

[Tn.Heritage]

Thanks for all the help   Anyone want a set of KBs 95" std no rings  oil rings bent and broke a comp ring on disassembly  also wadded the spiral keepers  Hate em  Who thought that up   Any takers?

  I've got some that I'll give them also, they had 3000 miles on them. Got tired of the thing sounding like a diesel truck. Actually went through 2 sets of KB's, 1st set collapsed below the wrist pins and the 2nd set just sucked. I fixed by boring 10 over with SE pistons, perfect.