Hoping y'all can give me some advice. 1999 FLSTC with Evo motor. Short story - spitting oil out the vent tube into air filter. Not dripping, but shooting out. Think somewhere between a water pistol and a super-soaker.

Long version/details:
It's been sitting for a couple of months. In preparation to get it back on the road, I removed spark plugs and checked them, then used the starter to turn over the motor with the plugs out until the oil light went out. I figured that would be a better way to make sure everything was getting oil at a low load than just starting it up. When I put the plugs back in, I discovered the battery had only enough power to turn over the motor without the plugs, but not with them in. It'd forgotten to plug it back into the battery tender when I parked it; even though I had plugged it back in a couple days before doing all this, I think the battery was toast (it was about 5 years old anyway).

The bike sat for a couple weeks again while I got a new battery. Installed it, and started the bike. It ran rough, and I noticed a bit of smoke coming off the exhaust cross-tube - it was because there was some oil dripping on it. I shut down the bike, and noticed a sizable puddle of oil underneath. Maybe a 1/4 cup or so? It always looks like more than it is. Saw it was coming from the air cleaner, so I removed that and turned over the bike. In about 2 revolutions (didn't actually start it), it shotgunned oil all over the wall of the garage. Not sure what to do, I came and searched this site. I came to the conclusion that maybe it was just too much oil in the crankcase; if not, maybe something serious wrong with the motor. I wired an old coffee can in front of the vent hole to catch the oil, and started it up again. It started and seemed to run normally, with no noticeable oil coming out of the vent. After a minute or so, as it was getting warm, and I increased the rpms slightly, oil started gushing out the vent again.

I don't have the tools to do a compression or leakdown test. Is my best bet to take it somewhere that does? Buy a set? Or just by a cheap endoscope off Amazon and see what I can see through the sparkplug holes? Or something else?

Appreciate any suggestions - thanks!

 

That’s normal when a bike’s been sitting for a while, I thought it only happened on bottom breathers though, hopefully someone else will chime in.

 

First thing you need to do is route the breather hose to atmosphere instead of the air breather.
Next is change the umbrella valves in your rocker boxes. Make sure to use OEM umbrella valves.
If that doesn't fix it then you need to open your cam chest and check out your breather gear.

 

Depending on how far you want to take it, in addition to new umbrella valves in the rocker boxes you might also want to consider drilling out the oil return holes a wee bit.

 

your oil is draining back into the case from sitting....... Clean your check valve in the oil pump.. Do you have a Factory Service Manual? Get one...

 

The other thing is that you can fire it up every couple of weeks or so. My bike had a little puking out the hose when it sat for a couple months. If I fire it up every couple weeks (but you need to let the oil get hot), it doesn't puke.

 

Thanks for the inputs. I'm pretty sure I have the factory manual - just have to find it (moved since I last used it). I'll try to tackle the umbrella valves and opening the drain hole and see if that helps.

If it didn't start right away, but only after a bit, wouldn't that indicate it probably isn't the check valve allowing oil to drain down to the crankcase? I would think it would start puking out pretty quickly if that was the case. Am I missing something there?

 

I would not do anything yet. Run it every couple days and don’t over fill it and see if it continues. Disconnect the vent into a container until you know what is going on.

I had a bad return side on an oil pump that caused the same issue when the gear pin sheared.

Do you have good flow back into the oil tank?

The manual states this is an outcome when you let them sit.

Good luck.

 

A cheaper and easier way to eliminate the possibility of bad umbrella valves is to purchase and install an external breather check valve and vent your breather to atmosphere at the same time. S&S makes a nipple kit for head breathers that you can attach fuel line hose to and connect the 2 together with a Y and then install the breather check valve... It's a lot less expensive and time consuming.. The following links are the check valve and then the Breather banjo bolt with the nipples..

https://www.ebay.com/itm/SIFTON-CASE...cAAOSwzrxUuDhJ

https://www.jpcycles.com/product/400...ather-bolt-kit

These are just examples and am sure they can be found elsewhere and cheaper..

 

Don't know about the OP but I'd rather change the umbrella valves than hang that stuff off my bike.
The umbrella valves are pretty simple to do and I'm a minimalist kinda guy. JMO