Author Topic: Oil leak around left crankcase cover (Read 8837 times)

captainshortypants · « **on:** March 29, 2005, 01:25:02 PM »

Hi folks,

I noticed that I have some oil leaking from the top of the left cover on the engine. I looked in the service manual, and it says that the 6mm crankcase bolts should be tightened to 13 Nm, and the 8mm ones to 22 Nm. Does anyone know which bults are 6mm and which are 8mm? I went ahead and tightened them all to 13 Nm, but I noticed this morning on my way to work that it's still leaking. Should I go ahead and tighten them all more to 22 Nm? Or does it sound like I just need a new gasket? The bike only has 12000 miles on it, so it seems a little early to be replaced already. Any thoughts?

Thanks,
Peter

Red01 · « **Reply #1 on:** March 29, 2005, 08:42:29 PM »

I thought all the bolts on the covers were the same size (in diameter). I don't recall if they're 6 or 8mm though. (You can always pull one and measure it.)

I've never used a torque wrench on those, just snugged 'em down to "German Torque" (gootentite).

Might be time for a new gasket, or replace the gasket with RTV form-a-gasket.

Have you ever been in there for anything? If not, it would be a good idea to take the cover off and check the torque on the stater clutch bolt. A few have been known to sneak out of the factory undertorqued, and if it backs off, the bike won't start with the starter. At least one has been known to fly off at high rpm and come thru the cover. (Happened to Dale Walker when he was running a bike on the dyno.)

captainshortypants · « **Reply #2 on:** March 30, 2005, 01:39:18 AM »

Thanks for the response and advice. I think I'll start with tightening the bolts more, to 22 Nm and see what happens then. My next step will probably be to work on the performance and smoothness of the engine, to prevent bolts from loosening in the future.

Peter

Steve · « **Reply #3 on:** March 30, 2005, 01:58:26 AM »

Peter

Be sure before you torque those bolts. If they are supposed to be @ 13 and you run them in to 22 you might do some damage. Determine the size of the fastener (a 6mm hex cap screw is what you usually tighten using a 10mm wrench) and use the correct torque. If that does not stop the leak you will need some kind of gasket.

If you are toqueing a fastener that has already been set to the proper tension, the correct way is to loosen the fastener before re-torqueing it. If you don't you can (most likely will) end up tighter than spec.

My .02, just don't want to see you writing back asking about helicoils.

Steve

Red01 · « **Reply #4 on:** March 30, 2005, 02:23:45 AM »

Quote from: "Steve"

Peter

If you are toqueing a fastener that has already been set to the proper tension, the correct way is to loosen the fastener before re-torqueing it. If you don't you can (most likely will) end up tighter than spec.

There's no "can/most likely" to it. You WILL over-torque it if you re-torque without loosening it first!

In the avaiation business, we used to have a common practice of ALWAYS making a click-type torque wrench click twice. A couple years ago, they made us stop this practice. We were shown a video that showed how much more torque was added just from this practice. It also included another eye-opener... how you hold the torque wrench and if you pull or push on it. I never would have thought these would have a significant effect, but the training video showed otherwise. Whenever possible, you should pull (smooth and steady, of course), with your arm at a 90* angle to the wrench.

Steve · « **Reply #5 on:** March 30, 2005, 02:45:56 AM »

I was trying to be gentle Paul, after setting the headbolt tension on my twins every 3 k miles for lotsa years I got pretty friendly with the 'ol torque wrench.

I would like to see your movie though, training films with real info are cool!

Steve

captainshortypants · « **Reply #6 on:** March 30, 2005, 01:02:09 PM »

Well, I took out one of the bolts and found that they are, indeed 6mm, so I didn't tighten them anymore. Looks like I'll need a new gasket. I'm glad it's a relatively easy repair. And like you said, it's a good opportunity to check the starter bolt.

Peter

Red01 · « **Reply #7 on:** March 31, 2005, 12:34:17 AM »

Quote from: "Steve"

I would like to see your movie though, training films with real info are cool!

If you're serious, I could see if it's still available. Since we have to share that kind of stuff with everyone in the company, it doesn't stay in the shop long.

You still have a VHS player?

Steve · « **Reply #8 on:** March 31, 2005, 04:10:40 PM »

Yeah Paul, that would be great! If you find it let me know, I'll get it back a little quicker than I have some other items.

Steve

Elmojo · « **Reply #9 on:** April 01, 2005, 10:32:32 PM »

I have the same problem with my '02 b12, and I've only got about 6K miles on the clock.
I bought a new gasket from Ron Ayers for $6.20 +tax and plan to replace it sometime this weekend.
I also got a 16 tooth drive sprocket that I plan to swap out at the same time.
I'd say replace the gasket, rather than using RTV or other liquid gasket. I wouldn't like the idea of little bits of rubber (or whatever that stuff is!) floating around in my oil supply. :(

Mike P.

Red01 · « **Reply #10 on:** April 02, 2005, 01:45:00 AM »

Quote from: "Steve"

Yeah Paul, that would be great! If you find it let me know, I'll get it back a little quicker than I have some other items.

Steve

Did some intranet searching for it tonight. Looks like the course number that it was under has been discontinued. If I can figure out how to find anything in the new library system, I'll see if the video is archived there. If I find it, I'll let you know.

FunGus · « **Reply #11 on:** April 21, 2005, 11:15:38 PM »

Hello all.

I have 4400 miles on my 1200 and I'm having similar leaks. I also have small leaks coming from the cylinder head bolts. Just a few drops.

BBurton · « **Reply #12 on:** April 22, 2005, 01:02:45 AM »

Trust me, use the new gasket and RTV sealer!!

FunGus · « **Reply #13 on:** June 02, 2005, 11:04:55 PM »

I finally fixed my leak. I gotta tell you that I was expecting the side cover to simply fall off when I unscrewed all the bolts but to my surprise, it was on TIGHT. I had to use a thin flat head srewdriver to slowly wedge it apart. The problem is that you risk scratching either the engine or the cover. So is this normal and if so, is there a better technique?

Red01 · « **Reply #14 on:** June 02, 2005, 11:40:21 PM »

It's not abnormal. You can sometimes get them off when they're stuck by sticking a couple of bolts back into the holes of just the cover about 180* apart and wedge them in the holes and use them as handles to pop the cover off.