Lower rockerbox gaskets keep failing!

[rvpilot]

Hi i need some some suggestions on my problem Please.
2018 cvo ultra I installed a S&S 128 sidewinder kit with cams and S&S oil pump. The problem is I keep blowing rocker box gaskets front and rear and the oil runs down from the spark plug weep hole out and down the cyc fins. I have replaced them 2 times. I thought I pinched them the first time so I was really careful the second time I did use the Jims gaskets both times. So any ideas on what I did wrong on the build before I pull the heads and check the head gasket install I am stumped on where to go from here. hopefully the pictures attach
Thanks Roger

[To The Max]

I would try OEM gaskets before i went any further .Max

[FXDBI]

I would try OEM gaskets before i went any further .Max

[rvpilot]

To me it almost seems like excessive pressure to find the weakest link to tear a gasket like that within 30 miles but where and why? I checked the breathers and the passages to the Air cleaner and a breather bolts and they're both goodI picked up some new gaskets from Harley this morning and I'll try them but they're not as stout as the Jim's gaskets

[To The Max]

The more i look at that picture the more it looks like the gasket was dislodged when fitted and was cut. can't see anything else doing that . good luck. Max

[cheech]

The more i look at that picture the more it looks like the gasket was dislodged when fitted and was cut. can't see anything else doing that . good luck. Max

It's a o-ring so to speak. No real pressure in the rocker boxes to blow it out as such.
So maybe wasn't in the groove correctly both times.

[rvpilot]

the first time i would agree that it was possible that it was not in the groove but the second time I carefully lifted both off just enough to see the bottom and looked with a flashlight to make sure they were seated before I bolted them down.
just to be clear this happened to both the front and the rear in the same spot 2 times. I put the stock harley gaskets in and I will run it later today.

[Sycho01]

Do the Jim's o rings fit in the channel correctly? How do they match up in diameter as compared to a set of stock gaskets? Obviously if the o ring is loose in the channel it will not compress and leak. Just a thought.

[SP33DY]

You might try a little trick I use for the rubber rocker box gaskets on Evo's.
Lay them upside down on a sheet of waxed paper and spray them with 3M Supper 77. Then carefully stick them onto their respective places on the rocker box.

[rvpilot]

Ok  third set of lower gaskets this one is stock gaskets and installed fueling dipstick breather and still have some leakage all tho not as bad. just did a leak down and its at 10% (now at 75 miles on upgrade) and I am getting air out the intake and breather on both exhaust is tight. these are fresh Ward performance ported. Any thoughts?.

[Sycho01]

Intake valves adjusted to tight? Not completely closing.

[rvpilot]

that was a possibility but I loosened up the push rods

[Jmd897]

Mine just went to today in rear lower rocker box.  Rubber "Potty mouth" sucks.

[Nastytls]

Have you put a straight edge on things to confirm there is nothing warped?

[clifford2004]

Friend had same issue went back to dealer many times cracked head.New head, fixed JS.

[FLSTFIDave]

We built my engine the end of March.  I put 15,000 miles on it since the build.  The rear lower rocker box started leaking oil.

We took it apart yesterday, and the lower rear rocker box gasket was pretty hard from the heat.  It had no visible bad spots, but you could see where it was leaking by.  The new gasket is a new Harley part number.  This one is green, black is what was in the bike.  This one seams slightly taller, not sure if the old one shrunk from the heat, or that may be part of the change.

Hope this one lasts more than 15,000 miles or 6 months.