I've got a dozen Evo's here. After sitting for more than a couple weeks they ALL wet sump, and puke oil thru the breather hose. It's been going on for years, some are worse than others, but they all do it except for the Dyna's where the oil tank is low, behind the trans.

I've tried everything from changing the check valve ball, re-lapping the seat, replaced the oil pump with an S&S on a couple. Still, the same problem!!!!

Does anyone have a proven solution? Perhaps a remote check valve, different oil type.

Any help will same the enviroment!

 

Then they ALL have a problem cuz its not the norm ...oil cant get past the check valve if its right..period.

 

Some are worse than others. The Fatboy, and one of the Springers are pretty good, but over enough time they will puke. Most of the others will puke after only about 2 weeks of sitting. A couple of the Dressers will puke about a quart after only about a week. I'm sure there must be some crap on the ball/seat with them! I know, the real solution is start them up more, but I have 2 jobs (3 if you count cleaning up oil spills) I just can't get around to firing up 40 bikes every week.

I completely understand the principal behind the check valve. The spring pushes the ball down against the seat to seal the oil from draining into the sump. When the engine is running, the pressure pushes the ball into the spring allowing the oil to pump thru the system.

That said, if the seat is clean, the ball is clean, the spring tension is correct, and the seal is perfect there should be no problem. But it's not a perfect world, something is preventing the seal. The slightest piece of crud will break the seal. I've seen it on other peoples bikes as well, and read other posts re/ this topic. Personally, I don't like the design.

A couple of my theorys why are, perhaps certain grades/weights of oil are causing a bad seal by leaving a deposit on the seat. I'm using Castrol 20/50. Sense I've tried several other oils with the same result, I don't think it's the problem. Maybe changes in barometric pressure could be causing a slight vacuume causing the ball to lift. Another thought is, could excessive heat change the spring tension causing less pressure on the ball? Has anyone tried to relocate the check valve, or use a different type?

Whatever the cause is, I really need a cure.

 

Sorry man..but i aint buyin it ...Good Luck just the same.

 

So what are you saying, I have 12 bikes, all with crap in the check valves? I guess it's possible, but there must be something causing it???

 

my 98 evo has never done that, I store it in the living room in the winter.

 

I added a brass shut-off valve in the oil supply line from the tank to the oil pump. It works great. You just have to remember to open the valve before you fire up the engine. I guess you could use an electrically activated petcock wired to your ignition also.

 

..... classic ........

 

You could sell your 12 bikes and buy a new softail with no oil bag to sump...

Seriously, any bike with a high mounted oil bag, see softails, sportsters and choppers will sump over time due to gravity. Some take longer than others, but they all will do it. You should check your oil bag before you start a bike that has been sitting for a while and if the oil level is low pull the plug wires and crank it a few times to get the sumped oil back to the bag, you don't need to get it all just get it flowing back that way then fire the bike and ride...

 

I won't let mine bikes at long enough to give me a problem....