Evo Oil Dilemma Harley Evo Discuss Evo Oil Dilemma in the Motorcycles forums; Hi All, My first post from OZ. Have a 94 Fatboy that allows the oil to drain from tank to engine if left standing for long periods of time. To ...

[trevblackman]

Hi All, My first post from OZ. Have a 94 Fatboy that allows the oil to drain from tank to engine if left standing for long periods of time. To make matters worse said oil will pump thru breathers, carby, and exhausts on startup. Believe this is not uncommon, but what is the cure? Suggestions?

[shovelmike]

It is a leaky check ball seat in the oil pump. I haven't ever had occasion to try it but I have heard of getting an extra check ball, allowing it to weld itself onto a welding rod and using it and a small amount of lapping compound to lap in the seat.....followed of course by a thorough cleaning.

[Shed]

Remove and clean the steel float ball and replace if okay if not purchase a new one.

[frisco-rigid]

Hey Trev

How long is a ""Long period of time"".? 5 days, 3 weeks, 6 months.???
If it's a relatively short time like 3 weeks then you gotta do something about it.. However, If it doesn't do it again after you start riding kinda normally but does start again only after looong lay-ups, you might try my lazy mans way below..

I've also heard of but never needed to try the lapping method..

Another method I read about but also have never needed to try is this..
Pull the cap and the spring and reach down in the hole with a clean brass punch of suffient length/size to Not prevent you from tapping the check ball smartly with a hammer..
A Brass punch because it will not harm the hardened check ball but will still transfer the blow..
The check ball (being harder than the seat) will hopefully "round" out the seat again.. Sounds good in theory but I have no idea if it works.. If I could remember where I read that tidbit I would give the author credit..

A lazy mans way could be this..
If you know the sickle will not be run for quite awhile get one of those hose pliers designed specifically to grab-crimp-pull and remove but not damage the hose.. Then you can remove the feed line hose at the oil pump, not spill any oil and plug the hose and the oil pump feed spigot.. Must take 5 whole mins.
When getting ready to ride again, set aside 6 mins. to install again..

[tagrat]

I had the same problem on an iron head Sporty. The quickest and easiest fix is to ride more often. Tell the wife/GF that you're saving money by riding the bike so you don't have to buy a new check valve.