I fired up my 1989 FXRS -SP , this last week. It did the same thing. I changed the oil ( as I do every spring) ran the **** out of It. And it quit leaking. I can not tell you how important it is to let these bikes warm up before you hit the throttle...

 

I think after mine is hot it stops bubbling.

If it's your Main Bike, Fix It.

 

I have done base gaskets on an evo before. It's a pretty easy job. The most aggravating part is scraping the old gasket off without doing damage to the metal. I never found a chemical gasket remover worth a flip. If you have a couple of days, a good collection of tools, a torque wrench and all the parts you need it's not a hard job. I used Genuine James base gaskets and HD everything else. I bought a top end gasket kit and the base gaskets separate. If mine were bubbling or leaking I'd just replace them. The more miles that are on your engine the higher the chance that more work may be needed even if it's just rings and honing the cylinders and/or some head work.

 

My bubbling evo has 45,500 miles on her for the record. I did let her idle for 10-15 minutes before the first ride of the season. I rode for about 20 minutes and put her away for another few days (another couple inches of snow). At the end of the ride it was still bubbling but not quite as much.

I will keep an eye on the situation for now but may take it down to the local indy for some piece of mind. This along with some oil dripping form the air cleaner makes me wonder if I may have a PVC issue as well. Crank case pressures may be part of the problem.

 

Well the "air in the system" is probably right in a way.
Bike possibly wet sumped over the winter and filled the crankcases with oil.
So when you started it up, it had a guts full of oil and developed high crankcase pressure for a while until the breather and oil pump could clear the excess oil and air pressure out of the cases.
The higher than normal crankcase pressure combined with the higher than normal oil level in the cases could have caused your bubbles.

Ride it a few times and see if the bubbling goes away before you tear into the engin.

 

It's not serious. Mine leaked/weeped/bubbled for 12 years before I had the Hayden 'The Oil Fix' installed. Actually, mine liked to bubble after I'd washed the bike. Probably a bit of Simple Green or other cleaner still left after rinsing.

The MoCo design leaves a bit to be desired when it comes to the oil return from the heads. Basically you have a hole in the head, that matches up with a hole in the jug, that matches up with a hole in the case. Only thing preventing the oil from leaking at those points is a gasket. Rather than install a hollow dowel pin in the jug that mates up with the hole in the case, which would prevent the oil from pooling inside the gasket, The MoCo put their money on the base gasket material. It was a good bet for HD, as most new bikes didn't leak until after the 12 month warranty expired. Not so good a bet for the owners, who had to deal with the issues.

IIRC, the stealerships get around 6 hours labor to swap out base gaskets. Plus parts. An average home wrench, can probably get it done in a day or a weekend, depending on what other issues 'come up'. Last time I bought a rocker box gasket set it was around $50 from their parts department. I have no idea what the rest of them would cost.

Personally, I wouldn't get it fixed until some other problems surfaces, or you were looking to tweak performance.

 

If you replace the base gasket, use Cometic base and head gaskets. The MoCo base gasket will just start leaking again.

 

1+ that's all I use tried James once had to go back & change them all

 

+2 on that, but, I will tell you, I've only replaced the base gaskets on one EVO, Bertha.

Imagine the HORROR when I started her up for the first time, and , sure enough, she was "bubbling" at the base gaskets....... After I broke in the new cylinders and rings etc.. It stopped......

 

Just figured I would provide an update in case another has the same issues.

After a few rides the bubbling stopped and now the weeping is minimal. My plan is to just ride for now and see what it looks like at the end of riding season. May consider opening her up this winter.

Another tech told me to shoot some WD 40 on it periodically in the winter to keep the gaskets moist. This will help out in the spring.

Appreciate the replies!