Small oil leak - suggested leak points?

Just recently, I have noticed a small oil leak if my bike is inactive for a couple of days and left on the sidestand. The leak materializes at the end of the sidestand on the floor and is about the size of a quarter. When I looked underneath, the lower left frame rail had an oil deposit and most of it was in the area right in front of the sidestand mount. I suspect when on the sidestand it ran down to the floor. The bottom of the crankcase was dirty but not wet. Nothing seems to be leaking around the shifter rod in the shifter cover. I made sure the bolts in the shifter cover are tight.

I have cleaned the area and degreased it. Here are the areas that I will be watching:
- oil filter cover
- oil drain plug
- oil sending unit
- area just under the alternator cover

As I said, I'll be keeping an eye on it. Let me know if I am on the right track or if you have solved this kind of problem in a different way.

Thanks.

 

You may want to keep an eye on the seal around the oil pan and the shift lever seal.

A slow leak in either of those locations might produce what you're seeing without being very obvious.

 

Probably old news, but...

When mine did that, I replaced my shift lever seal twice before I finally figured out where it was really coming from.

Did you know that those two hex socketed things on the sides of the engine are actually plugs? They are sealed with O-rings and both of mine have needed to be replaced over the years because they leaked:



I believe it's a 10mm hex key, and they're aluminum, so don't slip or you'll smear it. There's a corresponding one on the right side too:



Like I said, it's probably old news and I apologize if it is, but I couldn't find any mention of it in my service manual so maybe it's not a commonly known item. I did find a cutaway pic in the service manual that shows the lubrication system and you can see the O-ring on that drawing, but I couldn't find any text reference to it (in my SECA 550 manual).

Burnarr

 

There is no better frame of reference for one of these old bikes than an ORIGINAL OWNER. Thanks for that; "officially" those plugs never get touched and therefore need no attention.

 

Thanks, Burnarr, but it's not leaking from either of those caps.

 

Make sure it's not gas leeching down.

 

My XJ650J had a very small nagging oil leak similar to what you describe. Took me all summer to track it down, and it bugged the hell out of me. I even replaced the o-rings noted above on the both the oil galley plugs, but that wasn't it. I eventually found that even though the original drain plug was tightened properly along with a new copper crush washer, the synthetic oil was still getting by the plug as a very slow drip. Once I teflon-tape wrapped the oil drain plug, no further leakage problems.

 

CHeck the breather tube for a crack, lose fit.
It is right above the area were you have found a leak.

 

I cleaned the area around the oil drain plug and will keep an eye on that.

I also moved the breather tube back a bit to eliminate that as a possibility. Will keep an eye on that area, too.

Thanks, guys.

 

Yeah, leaks can be a real pain to track to the source. Mine took me a long time to find and when I finally traced it to those oil galley plugs I was very surprised to see just how far the oil traveled before collecting.

The leak was all the way up at the front left corner of the block where the left side plug is, but the oil dripped right onto the frame tube there and wicked it's way all the way back to the sidestand and shifter area before becoming evident. It was amazing just how far it traveled!

Heh. That's me! Maybe my slogan should be "Bought Her New In 82." :lol:

I think those plugs should have been sealed with silicone or something at the factory. If they were never intended to be messed with ever again, then O-rings were obviously a poor choice. I've actually been through two sets of O-rings on mine since new and I believe part of the problem is that they get very hot and may, in fact, be exceeding their rated temperature spec. I think the next time I change my oil I may change to silicone sealant instead. :idea:

Burnarr

 

Still looking...and I came across this thread:

http://www.xjbikes.com/Forums/viewtopic/t=3771/

I have been wondering about that little blue wire and what it is for. The area where this blue wire is connected under the frame rail has the highest probability for the source of the leak. The wire can be moved side-to-side with a screwdriver, so it isn't really tight. From the looks of it, the exhaust has to come off to tighten that screw. Is that the case? How is the neutral safety switch installed? Is it easy to take out?

Has anyone else had a small oil leak from the neutral safety switch?

 

Hack: Yes, a handful of members have had this issue. It threads in but some folks had to move the engine in addition to removing the exhaust to get at it.

 

If your bike has stock exhaust you have to remove it to get the switch out. Tightening the screw did not help mine, it was leaking out through the internal seals of the switch itself, and then down the wire, and onto the frame rail. Here is follow up to the thread you linked...
http://www.xjbikes.com/Forums/viewtopic ... art=0.html
explains how I got the switch out, and replaced. Have not had a problem with either bike that I did this to since.
NTgirl

 

Thanks, NTgirl. I ordered a new switch from Chacal today and will wait for it to arrive. The modifed socket is a great idea. I bought a deep 14mm six point socket today and took it to the machine shop to have it turned down. They only felt that they could take about 1/16 off and were going to charge me about $30. It didn't seem like a lot to me so I will try it and see. Maybe I bought a thin walled socket? Do you thing taking 1/16 off will make a difference? It will be great if I don't have to move the motor. I'm sure getting the exhaust off will be enough of a chore.

Again, my compliments on a creative solution.

 

The shop I took my socket to charged $5. And there was not much to be taken off, but it would not fit otherwise. You will see what I mean when you try it. There is a recess around the switch that is only about 1/16 wide, and the hex part of the switch is only about 1/8 thick. So if you don't get a straight on shot, it won't work. I could not find a thinner wall socket anywhere. I don't know if a deep well will work...because it's kind of a strange place that you need to get to. Others here had suggested loosening the motor mounts, but I think what I did was easier and quicker. The only worry I had was the socket being weak, but luckily neither of the switches I replaced was in extremely tight. $30 seems a bit steep for a 2 minute lathe job. Did you ask around?

 

Well, what's done is done as far as the machine shop charges go. I should have checked around, but live and learn.

The deep socket that has been turned down doesn't fit between the frame and the oil pan on my 750 Maxim. I guess I will have to move the motor over a bit. I can see the motor mounts on the front, but on the back...are they the nuts tucked behind the foot peg mounts?