Oil leak when motor cold?

Hi guys, quick question I can't find a answer to. My 400 seems to have developed a slight leak when it first starts. Seems to go away when warmed up. What would cause that? Would too much oil do that? I filled up the case so that there is just the smallest bubble visible in the sight as when it gets warmed up you can't see any oil in the sight. I do seem to remember that is normal but it still freaks me out a tad.

 

Oil leaks are not normal. Wheres the leak? Oil level should be between the two marks in front of the site glass post pictures if you can. Sounds like you have to much oil in there.

 

O-ring type seals will do that...they expand as they warm up, sealing small leaks.

Check your valve cover and filter housing.

VC has torque limiters on the bolts...tightening may not change anything. New ones would be the answer, generally.

 

Yes, when you run the bike the oil in the window will disappear. It takes a good 5 minutes to come back to "visible" again if the motor isn't fully warmed up. Don't fret that.

Where is the minor oil leak from?

 

Sorry, should have mentioned where it was coming from.

About 90% sure it is coming from oil filter housing. It was dribbling previously from the same spot but some JB weld stopped it until I did the oil change.

Would it be alright to weld any little cracks on the filter housing cover? That was the plan for when the bike goes into hibernation in a couple weeks.
I have been looking around for a replacement but have come up empty.

Should add that I had a new O ring and check valve bolt put on as the old one had been torqued way too much and I had to mangle the thing to get it off. Not sure if the over torquing would have caused a slight crack or slight warping of the cover or if it is just slightly too much oil.

 

It's located on the absolute bottom of the motor, isn't it?

It wouldn't drip from "too much" oil. I suspect you may be right about the cover, it may have been damaged in some respect as you mentioned.

Pull the cover and carefully inspect. You should be able to find one on eBay if nothing else.

You could weld up any cracks, but I would be very concerned about distorting the cover. Probably best to scrounge a replacement.

 

Instead of welding up the cover you might want to consider upgrading to a spin on type filter. Much more convenient at oil change time than those dumb cartridge filters.

Ill bet Len at XJFOREVER could fix you right up!

Loren

 

Not practical/feasible on the "XJ" XS400 twin; it's on the exact bottom of the motor and recessed into the sump, the cover is only about a quarter the height of the typical front-mounted XJ 4-banger.

From looking at the manual, are you sure the oil isn't actually coming from the drain plug just forward of the filter? Did you put a new crush ring on the drain plug?

 

Hmm, I would have to double check to see if it is the cover or the drain. Don't think I put a new ring on the plug.

Yeah, the cover has been hard to find on ebay. Have been looking since the original leak and never come up with anything for the 400s, just the 4 bangers.