Bell Housing Leak

[GuzziMoto]

Understood. I counted your post among the opinions that there is no check valve in the V11. 

 

If there is a valve, it would be exactly as gstallons noted: like a PCV valve on a passenger vehicle. These are simple ball valves that are "pulled" open by intake vacuum. As noted, the upper (spine) frame member receives the crankcase vent hose and the oil fraction settles in the frame returning to the crankcase through the return line on the lower left side of the frame. Intake vacuum is applied from the airbox by a hose that connects the forward left side of the airbox to the banjo fitting visible at the top of the frame just behind the headstock pulling the oily vapor portion from the crankcase back into the aibox. If there were a check valve, it would be "opened" by this vacuum.

 

So far, I'm with GuzziMoto and moto fugazzi, also baldini and czakky :    "No PCV check valve on the V11."

 

I've amended the "Tank Off Maintenance Checklist" in FAQ.

 

Anyone finding a check valve in their vent pipe under the crankcase vent hose needs to "pipe" up!

Yes, except for the part about intake vacuum. The vent at the top of the frame connects to the airbox, not to the intake manifolds where there would be vacuum (that is how some cars have done it). The intent is merely to use the air filter to prevent dirt from getting into the system and for any oil mist that might make it through to either collect in the airbox or possibly get burned by the motor. But there should be no noticeable vacuum in your airbox or something is wrong. Your airbox will have low and high pressure pulses rippling through it, but unless something is wrong you should not have vacuum. And any vacuum you could create, like from putting in a one way valve, would pull not only on the crank case vent but also on the oil return line. I know that because I tried it and it suck oil from the case up the return line.

[gstallons]

That's why I said "similar to" not the "same as" a PCV valve. There is no manifold vacuum on this vent system. This ball valve "I think" allows vented crankcase gases to escape the engine and oil to gravity feed back past the ball back into the crankcase.

[docc]

 

Understood. I counted your post among the opinions that there is no check valve in the V11. 

 

If there is a valve, it would be exactly as gstallons noted: like a PCV valve on a passenger vehicle. These are simple ball valves that are "pulled" open by intake vacuum. As noted, the upper (spine) frame member receives the crankcase vent hose and the oil fraction settles in the frame returning to the crankcase through the return line on the lower left side of the frame. Intake vacuum is applied from the airbox by a hose that connects the forward left side of the airbox to the banjo fitting visible at the top of the frame just behind the headstock pulling the oily vapor portion from the crankcase back into the aibox. If there were a check valve, it would be "opened" by this vacuum.

 

So far, I'm with GuzziMoto and moto fugazzi, also baldini and czakky :    "No PCV check valve on the V11."

 

I've amended the "Tank Off Maintenance Checklist" in FAQ.

 

Anyone finding a check valve in their vent pipe under the crankcase vent hose needs to "pipe" up!

Yes, except for the part about intake vacuum. The vent at the top of the frame connects to the airbox, not to the intake manifolds where there would be vacuum (that is how some cars have done it). The intent is merely to use the air filter to prevent dirt from getting into the system and for any oil mist that might make it through to either collect in the airbox or possibly get burned by the motor. But there should be no noticeable vacuum in your airbox or something is wrong. Your airbox will have low and high pressure pulses rippling through it, but unless something is wrong you should not have vacuum. And any vacuum you could create, like from putting in a one way valve, would pull not only on the crank case vent but also on the oil return line. I know that because I tried it and it suck oil from the case up the return line.

 

Thanks for helping my understanding on that. Makes good sense!

 

I thought there would be at least a little vacuum at that airbox tap, but my vacuum gauge agrees: none.

 

Apparently, the nasty oil haze that gets into the airbox is driven by crankcase pressure.

[docc]

I have some leaking at my bell housing as well, and it doesn't smell like gear oil. The breather hose was replaced this year, and there's no leaks from there. The leak is getting gradually worse, but isn't bad yet. I wonder if I can remove the starter and take a look inside with a mirror and flashlight to find the leak?

FWIW, I'm told the PO had the rear main seal replaced under warranty at under 1K miles.

Ken

I wondered the same thing about the starter access. I looked at all the manuals and diagrams and I don't think there is any room for inspection. I was hoping just to be able to spray some cleaner through to flush the nastiness then watch, wait, and hope!

 

Click on the link to Pete Roper's post, above, and he details the leak culprits; all the rest of which would require the gearbox pulled.

 

moto-f: not wet and dirty on top around the vent hose connection?

[moto fugazzi]

Not wet and dirty around the vent hose at all. I did remove the inspection plug on the RH side, and it looks like there's a little bit of oil in there. I sprayed it out with cleaner the other night, and I'll check later if there's more oil in there.

Ken

[docc]

Good news for those worrying about the rear main seal: After tightening the crankcase vent, this is how the weep hole area looks after about 100 miles;

[docc]

Seems that after sitting for a couple weeks, then riding about 35 miles, the leak has returned.

 

Also, the blank over the distributor access is wet. Fasteners are tight. I suppose the good news there is it will be easy to get to with the gearbox out and spine frame crabbed . . .

 

[moto fugazzi]

Seems that after sitting for a couple weeks, then riding about 35 miles, the leak has returned.

 

Also, the blank over the distributor access is wet. Fasteners are tight. I suppose the good news there is it will be easy to get to with the gearbox out and spine frame crabbed . . .

That's exactly what my bike looks like after a 35 mile ride. Let me know what you find when you open it up. I was going to take mine to my dealer today, but 22f and 30+mph winds, I changed my mind. Should be 30f on Monday, so I'll ride it there then.

Ken

[docc]

HAHA! I was waiting to see what YOU found!

 

Now I'm making a list of everything a properly fettled 89,000 mile V11 Sport ought to have on a winter tear down . . .

 

Ken, I know you started another thread on your leak, but what say we combine results? (I bet we won't have the last two wet weep holes on the planet . . . )

[gstallons]

Docc,

 before you tear it down , you should add a dye to the engine oil . Ride it for a while .... then tear it down . You can the use a UV light to see exactly where the oil leak is coming from.

[docc]

Docc,

 before you tear it down , you should add a dye to the engine oil . Ride it for a while .... then tear it down . You can the use a UV light to see exactly where the oil leak is coming from.

Roger that. Good plan. Thanks!

[moto fugazzi]

 

Docc,

 before you tear it down , you should add a dye to the engine oil . Ride it for a while .... then tear it down . You can the use a UV light to see exactly where the oil leak is coming from.

Roger that. Good plan. Thanks!

 

I put 1/2 bottle of UV dye in my bike a few months back in order to locate the leak. The dye isn't showing up through the bell housing hole. I was hoping that the leak was from the gasket above the oil pan, but it isn't. Maybe I just don't have enough dye in there, or perhaps it's already stained the inside of the bell housing as it leaks down through to the vent hole.

 

Feel free to merge the threads, or delete mine, as they seem to be fairly similar. I'll post findings as my bike gets taken apart. I'd do it myself if there was any chance of the temps getting back into the 40's in the next few months. Probably won't get back into the 70's for at least 4 months here.

Ken

[docc]

Let's leave the other thread for sure. I think it has a link here. If we compare notes and findings here, I think it makes later searches more effective.

 

From what Roper said, a rear main seal would really put out a lot of volume and it's right above the weep hole. Makes it (perhaps) more likely it's one of the other sources.

[andy york]

I don't know....Sounds to me like you need to strip the engine and tranny down to the last nut and bolt

and really find out what the problem is.

 

                            

[gstallons]

 

 

Docc,

 before you tear it down , you should add a dye to the engine oil . Ride it for a while .... then tear it down . You can the use a UV light to see exactly where the oil leak is coming from.

Roger that. Good plan. Thanks!

 

I put 1/2 bottle of UV dye in my bike a few months back in order to locate the leak. The dye isn't showing up through the bell housing hole. I was hoping that the leak was from the gasket above the oil pan, but it isn't. Maybe I just don't have enough dye in there, or perhaps it's already stained the inside of the bell housing as it leaks down through to the vent hole.

 

Feel free to merge the threads, or delete mine, as they seem to be fairly similar. I'll post findings as my bike gets taken apart. I'd do it myself if there was any chance of the temps getting back into the 40's in the next few months. Probably won't get back into the 70's for at least 4 months here.

Ken

Are you using a  UV light & glasses (w/the dye) to find this leak ?