I posted a while back trouble shooting no oil pressure and finally got around to opening the cam chest on my '96 fatboy. I attached a few pictures of what I found in there which looks like a shredded oil pump pinion shaft gear and a breather that was chewed as well. Looking for opinions on potential causes and what I should be looking at to find a proper solution moving forward. It's hard for me to believe how good it sounds running when it looks like this inside. I removed the oil pump first and everything looked pretty good in there to me except a piece of the sheared gear fell out of the inlet passage but the housing and gears appear to be in good shape. I think it is also worth noting that the inner (sump side)oil pump driving gear is firmly in place and I am still having difficulty removing it from the shaft but neither key appears to have sheared.https://youtube.com/shorts/klJLNC17BXU?feature=share

 

Sorry about your engine problem. Did any of the lifters fail? It could just be that your gear drive had metal failure? What took out your drive gear got between your cam gear and breather gear. Someone will give you a better diagnosis. I would really inspect your oil pump carefully and see that there are no scarring on the gear cavity (like lines gouges). I really doubt that your oil pump survived. You will have to also inspect your breather gear cavity for scarring.

Cut your filter and inspect the element. If there is any metal debris, etc....do not just fix what's in the cam chest, replace oil pump, flush lines, etc.....IT'S NOT ENOUGH! Split your case and flush it out. I learned the hard way, and wouldn't want others to make the same mistake.

 

How's the inner cam bearing look?

 

This is what the oil pump looks like right now. I'll be pulling the bearing tomorrow

 

Pump looks good to me. I think something got loose in the timing chest, found the gears and poof. Piece of lifter, cam bearing, etc.

 

Judging by the amount of debris in the scavenge side of the pump and the fact you cannot remove the one scavenger gear, tells me the scavenge side locked up taking out the pinion shaft gear and most likely the Breather gear as well.... As noted you will need to disassemble the motor to find what gave way first to lock up the scavenger pump...

 

Aloha,
from my point of view it looks like the oil pump was blocked and the driven gear shredded the pinion shaft gear.
What looks interesting are the missing teeth from the breather valve.
Was it easy to remove?
Probably something blocked the breather valve a tooth get broken and moved between the pinion and drive gears and blocked the pinion shaft.
Or there is just a simple material fault.
Is there any huge clearance at the oil pump single parts that's not normal?
Or small scratches or notches in the surface?

 

I just watched your video. That's a cool way to check oil pressure. Not knowing if you had any previous engine work, I'm going to assume that your engine is stock except for the air filter and exhaust, which is loud and does mask sounds. Based on the look of your timing cover, plastic breather gear, stock lifters, and OEM gaskets, I'm going to assume you have a stock engine. If so, how many miles is on your bike? The two most common failures are lifters and cam bearing (you have the INA cam bearing in '96). Based on the sound in the video, it doesn't seem like a lifter noise, so your cam bearing is the suspect. I'm sure you will know today when you pull it. Re-inspect your lifters and lifter blocks carefully also.

As to your oil pump, in the real world, I guess you can run it, and it would work. Personally, I would not run it if the surface wasn't smooth. There are plenty of good take off pumps from 92-99 that you can pick up, because lots of guys change out to S&S pump, or whatever. I have two bad 91 and earlier pumps that I will not run because they do not have perfectly smooth cavity. It sucks, but you have time to hunt down a good clean pump. Best of luck on your investigation.


Just an example, Pinwall is where you can find good OEM take-offs. With some research, you can get deals. https://www.ebay.com/itm/1993-1999-H...IAAOSwBkBgIZ~R

 

There is no way of knowing what is inside the crankcases, or has contaminated the oil passages and bearings.

If it were my bike I would not spend a penny on that engine until it was completely disassembled and inspected.

 

Those marks in the oil pump that Daven9113 posted seriously look like a cam needle bearing mark in the housing AND...

Dan89FLSTC is absolutely correct....