Rear Cylinder Base Gasket Leak

[2rooper]

Okay, lets get this part out of the way, I am new to owning a shovelhead, I have heard that they leak all the time.  I have a small oil leak (like a silver dollar size stain on the pan after a ride) at the rear cylinder base gasket.  Bike is running very well.  I know a few of the mods on the bike but I do not have details on all.  It is electronic ignition, it has had some head work but they are still single plug.  Should I be concerned or is this par for the course?  I personally am not big fan of my bike marking it's territory but if this is normal I can deal.  Also, is there such a thing as a leak free Shovel, if so what does one have to do to get there?  Again I would rather ride it more than wrench on it if possible.  Thanks for the input.

[easyricer]

There are some leak free Shovels out there, but if you ask me, I kinda liked my Shovel dripping in peoples parking lots. I really loved pulling up to a Harley shop just to drip and browse the pretty shiny things in the store. 
Even my ol Betsie was drip free for a little while, but then my tranny decided to let some oil go. I'd much rather ride than worry about leaks.
If the base gaskets are leaking it can get pretty ugly between washes. As long as she's running good let it be until some down time, like snow on the ground or too hot to want to ride. My ol Gal gets washed once a year, whether she needs it or not. For right now, she's being rebuilt, so she might not leak for a few days anyhow.
EASY

[Mule]

If it isn't leaking bad leave it alone until It needs top end work. Chasing oil leaks on a shovel unless REAL BAD is not a good idea, it will just find another spot to drip...If it works don't fix it there will be plenty of time down the road...

[96flhpi]

I've had some luck fixing a weep at the rear cylinder base by cleaning the area and smearing some high temp rtv at the joint, like you're caulking a bathtub.  Like I said it was a weep so may not work in your case.

My '82 is currently pretty much free of full on leaks, but sure weeps from a lot of places, occasionally get a drop or two on the ground.  Before I rebuilt it, my tranny leaked at the sprocket so much I had to refill it before every other ride.

Welcome to the site and the wonderful world of Shovels.

[76shuvlinoff]

make sure the case vent is open to atmosphere

[motorplex88]

I would be hard pressed to tear into a good running shovel over a small leak.  A few weeps and seeps never really bothered me but a full blown Exxon Valdez situation deserves attention.

[bob_e95482]

It's taken me 20 years, and a lot of money, but I have a leak-free Shovelhead. It weeps a bit from the base gaskets, BUT NOT ONE DRIP. I also have a belt drive primary and a Rev Tech 5in4.

[vern]

On a ride to Holister years ago my Shovel blew a base gasket, I used crazy glue to hold it in place and never looked at it again, in fact it held for a few years.

[2rooper]

Thanks for all the responses, based on what you are all saying, I should just ride until I actually need to tear into it!!!  Where is the crankcase vent that I should be checking to make sure it is open to the atmosphere?  Sorry for the rookie engine questions, if we were talking about a small block chevy I would be all over it

[motorplex88]

Crankcase vent is just to the bottom left of the oil pump looking at from the rear in the case itself. Folks put various kinds of filters on the end of the hose that can get clogged up.

[76shuvlinoff]

Typically the crank case vent runs over to the drive chain to provide a bit of lube to the chain. Then it slings it over.  Most guys reroute them and some put catch cans or filters on em. Sometimes they get run into the back plate on the carb air cleaner. I vote no on that one.

[v10ole]

Hello all, haven't been on here for quite a while but cant help but say that my shovel don't leak and if it does  I fix it that how it is.... The great part of that is its not rocket science its a shovel. now the bad part these old girls like a lot of attention like a woman don't give them what they need the next thing you know they bite you in the ass, that being said if you don't have a tool box buy one. The investment can leave you with a bike you know like the back of your hand every noise for me the best part of owning one.... Yep ask anyone here they like attention but give many miles and smiles..  

[76shuvlinoff]

I've had some luck fixing a weep at the rear cylinder base by cleaning the area and smearing some high temp rtv at the joint, like you're caulking a bathtub.  Like I said it was a weep so may not work in your case.

I used Automotive Goop like caulk on a rocker box weep once. It held till I got some good gaskets the next winter.

[Ultrashovel]

If your Shovelhead isn't leaking, it's probably out of oil. LOL.

More seriously, I don't recall seeing too many shovelheads (panheads, flatheads, knuckleheads) that didn't have a leak here and there. In the early days, the castings were not all that precsion and tolerances were looser since the engines, transmissions, and other castings on the bikes were built using manual milling machines, drills and lathes. I don't know if they still do it, but the early bikes had orange shellac painted inside of the crankcase halves to keep oil from seeping through the porous alumimum cases.

In fact, I've stopped a few leaks in the aluminum cases by bopping them with a ball peen hammer. It actually works. LOL.

I had a 1982 FXS for close to 15 years and it had a persistent transmission leak through the countershaft sleeve. On the good side, it only leaked enough to keep the rear chain wet so I removed the rear chain oiler and forgot about it. I had a nice oily chain, too.

Just check your oil and keep on riding it. You'll see the inside of the engine soon enough, 

Happy Trails.