Wow jackass is an understatement for that guy. I won't try to argue anything I don't understand to avoid making an *** outta myslef like he did. I didn't think they had an umbrella valve until the breather assembly was taken out and shown to me by the tech.

They tried to modify it by putting a washer on the tit of the umbrella valve to see if it would help tighten up the valve a bit but it didn't do anything to remedy the oil puking from the rear breather. I just hope that Zipper's is willing to stand behind their products and make it right somehow if they can't solve the problem.

 

FWIW, it wouldn't be called a "umbrella valve", but there is such a thing as Umbrella Valve Seals...They don't open, they shield the valve guides from oil like an umbrella would

 

Ya learn something every day. Thanks.

 

This is what a Sportster "breather" looks like unlike the umbrella valve on a big twin.

 

This is an "umbrella" valve from a big twin.

 

That is the breather they showed me but they took that piece of foam out and it had a similar looking umbrella valve to the one in the second picture you posted. They put a washer on that tit that the pencil is pointing to.

 

Ahhh, so we do have an umbrella valve but it's inside the breather assembly, good to know.

 

This is all true for "04" and up sporty's. Before that, they had two umbrella valves and no breather assy. Just to keep the thread straight for us older sporty owners that may revive this thread in 15 years from now.

Here's mine. Just changed them. One in each rocker box cover spacer plate... Yea. Rocker box cover spacer plate. Something else the newer sporty's don't have.

 

 

Just thought I would give an update on the situation. Going on 4 months now of not having my bike.... but there is some light at the end of the tunnel. Zipper's has run a multitude of tests and measurements amongst other varius checks and measurements. They found that the rear breather valve is not sealing at all even though it's brand new. The vent holes in the breather bolts are also too small for the bigger bore engine kit to function properly. This is causing a pressure imbalance which is making the oil puke out. Also there was a valve guide seal that was leaking a bit. Just thought I would show this pic of the breather valve showing the umbrella valve inside.



Zipper's also found that the rear piston was damaged either during disassembly or shipping. It was evident that the piston had not been run like this and the damage was fresh.




Everything else checked out fine. All gaskets were sealed perfectly, piston rings were sealing correctly, cylinders have no issues at all as well as with the heads.

Zipper's has deemed the rear piston unuseable and will replace it with a new one and rings. They are gonna brush hone the front cylinder and provide new rings for this piston. They are gonna clean everything, touch up the valves and seat surfaces, replace all valve seals and supply new gaskets for the heads and cylinders. They are also gonna bore out the breather bolt holes from .062" to .150" for proper crank case pressure and oil circulation.


On top of all of this, since I live at 7200 ft elevation and ride at higher elevations regularly, they also offered to replace both pistons with pistons that have a higher dome volume to increase the compression and in their words "dramatically improve the engine performance at high altitude operation." They said that on a hot day the corrected altitude here can be around 10,000 ft or more due to the heat. This ultimately affects the engine performance as if I were riding up at 10,000ft elevation which equals less power and torque than it should put out. This might explain my relatively low dyno numbers for this kit.

All of this is being done at no cost, again in their words "to help me get this engine on the right track." This is amazing to me. I was totally expecting to pay a whole bunch for this. I have heard some bad things about Zipper's and bad customer service but it really seems they are making this right for me. Maybe they are in the process of repairing their damaged reputation or whatever but they are most definitely standing behind their products and not only making this right but going above and beyond by supplying the pistons to make it even better. It seems they are really trying hard to make me a satisfied customer and are doing a pretty good job at accomplishing this.

Thank you Zipper's Performance. Now to just hurry up and wait for everything to be shipped back and hope the HD shop doesn't damage anything else during reassembly.