I have a 98 dyna with a 96 ci S&S motor this all started when I replaced the rocker box seals on my rear jug. I rode the bike around for three days before this started. I took off on a trip out of town and made it about 20 miles before the engine started smoking from the exhaust and was covered all over the right hand side. I shut it down and checked the oil a whole quart was gone maybe more. got it trailered home cleaned it up and it was blowing oil out the rear head breather into the carb . I tore it all apart again cleaned all ports replaced the gaskets and umbrella seal and all the pushrod tube seals as well fired it up and now its blowing oil out of the front head into the carb. I never touched the front jug but none the less I pulled the covers off and replaced the umbrella seal still doing it am suspecting oil pump at this point or am I off base? By the way compression check show 165 on both cylinders and it runs just as it always has only the more rpms the more oil blows out

 

I dont think its the oil pump- unless the scavenging gear(s) are toast. Make sure that oil is returning to the tank. If it isnt- check for kinks or blockage in hose.
If your rings and cyl are worn- or you have a broken ring- or your rings were installed incorrectly- you could have excessive blow-by the rings and you would be pressurizing the crankcase (which would start to blow oil out). A compression test should determine that.
Im sure others would have some ideas too.

 

Quit putting oil into it!!!!
Search Sumping..... You may be causing yer own problems...

 

Thats what i forgot to add- dont put too much oil in!!

 

compression tests show all good 165 both cylinders had this bike three years changed rocker box gaskets twice and re did head gaskets when I first got it its never been a problem til now so I think it may be in the oil system or the breather gear

 

Cool... ya got it covered then?

 

Since youve had the bike for 3 years already- im sure you know how much oil to put in before it'll puke.
I'd check your hoses to the tank-make sure nothing is blocked and oil is going back to the tank-or check that breather gear like you said. Do whatever you think is easiest first. Good luck!

 

A leak down test would determine more than a compression test at this point...

 

 

I agree. My rear cylinder showed 160 psi with one broken compression ring. Combustion pressure is about 4 times higher than cold compression.