Welcome from Ohio

 

 

 

 

 

Don't think your making enough power to flex that shaft. I would first take a look at the vent and make sure it's not plugged.... Also depending on mileage could just be a worn seal.... Are you sure it's not the IPB seal?

 

I'm not sure of the strength of the main shaft, but it was right after the upgrade. Someone on you tube did the exact upgrades I did, with the same issue. He upgraded his mainshaft to an Andrew's performance shafts built for performance bikes to solve his problem. Seems like 100 hp is not enough power to bend or wear anything out. All seals except the one leaking. The seal behind the pulley has been replaced twice with only a couple hundred miles on it, then back primary seal went out, replaced it, now the seal in the main shaft behind the pulley is out. I don't know the milage on the trans, so, I'm thinking just rebuild it.

 

Reaper, my 2005 Night Train, has similar engine upgrades (98ci, gear drive cams, high comp, etc... ~100 hp / ~116 ft-lbs), with about 140,000 miles, since the build, and over 151,000 miles total on the bone stock transmission. The only time I had a trans leak (aside from the typical shift shaft seal leak) was when the inner primary bearing inner race, pressed onto the trans output shaft, walked inward and took out the seal. That happened about 4 years ago. I replaced the stock 2 piece bearing with a Baker one piece unit, and haven't had a drop spill out since.

Cheers!

 

If you are changing the main seal I would change the quad seal and the pulley spacer at the same time.