Oil Leak
- Fraser
- Posts: 334
- Joined: Tue Jan 17, 2006 12:00 am
- model: 750 Paso
- year: 1986
- Location: Lower Hutt, New Zealand
Oil Leak
Here is the story. Went out for a ride during the weekend, all good, but the chain felt a bit loose and decided that it needed an adjustment. Two days later was in the garage to adjust the chain and noticed a pool of oil under then main stand. Ignored this and went on adjusting the chain. Had it right and was spinning the rear wheel to check all OK and the wheel stopped. The chain was tight at this point, so adjusted it to give clearance and then spun the wheel. The chain was then really loose at all the other points except where it was adjusted, time for a new chain. So decided to leave this and look for the oil leak. The trail of oil was not so clear and had spread around, but there was a suspicious amount below the drive sprocket cover. Removed the cover, drive sprocket, chain and cleaned it all up. Apart from the sludge and build-up from the chain it did not seam to bad. So, started the motor and ran for 10 minutes or so for the oil to get good and hot. No leak. Have left it an hour or so, but still no leak.
My theory is that the tight spot on the chain put a load on the sprocket/drive shaft, which let some oil, seep out. Without the sprocket and chain fitted there was no load and hence no oil leak.
Possible or just wishful thinking.
Fraser.
My theory is that the tight spot on the chain put a load on the sprocket/drive shaft, which let some oil, seep out. Without the sprocket and chain fitted there was no load and hence no oil leak.
Possible or just wishful thinking.
Fraser.
- Desmo_Demon
- paso grand pooh-bah
- Posts: 869
- Joined: Fri Jul 21, 2006 12:00 am
- model: 750 Paso
- year: 1987
- Location: Easley, SC
- Contact:
Yes, it is very possible. I've seen several chains that have stretched at an uneven rate, causing a tight/loose situation when the wheel is rotated, as you have. Definitely replace the chain. It's a good thing that you didn't adjust the chain on a loose section of chain, then run down the road and bent your transmission output shaft or tear up the output shaft bearings.
For the oil leak, I would suspect as you have. You probably won't see any more leaking until you get the transmission spinning, again, and there is a slight chance that the output shaft seal is bad, now (heat build-up...unever wear). I'd just keep an eye on it. If the seal is leaking on a regular basis from this point on, either replace it, or let it lube your chain and keep an eye on your engine oil level......actually, because of the type of bike and how it is driven, I really don't recommend the second suggestion......
My Harley has had an output seal leak for over 30k miles. I just let it lube the chain and keep an eye on the transmission fluid level. On a sportbike, I'd be more afraid of the seal finally letting go and coating the rear wheel with oil.....I only use my Harley for daily commuting to-and-from work......on straight, boring roads. I did try to fix it a few years ago, but I can't seem to do it from the outside of the tranny....I'll repair it when the tranny needs to be rebuilt...88k miles and still holding.
For the oil leak, I would suspect as you have. You probably won't see any more leaking until you get the transmission spinning, again, and there is a slight chance that the output shaft seal is bad, now (heat build-up...unever wear). I'd just keep an eye on it. If the seal is leaking on a regular basis from this point on, either replace it, or let it lube your chain and keep an eye on your engine oil level......actually, because of the type of bike and how it is driven, I really don't recommend the second suggestion......
My Harley has had an output seal leak for over 30k miles. I just let it lube the chain and keep an eye on the transmission fluid level. On a sportbike, I'd be more afraid of the seal finally letting go and coating the rear wheel with oil.....I only use my Harley for daily commuting to-and-from work......on straight, boring roads. I did try to fix it a few years ago, but I can't seem to do it from the outside of the tranny....I'll repair it when the tranny needs to be rebuilt...88k miles and still holding.
2002 Ducati 748 monoposto
1998 Ducati ST2
1996 Suzuki GSXR-1100
1994 Bimota DB2
1988 MegaPaso 916 project
1987 Ducati Paso 750
1985 Harley FXEF
2001 Ducati M900ie (wife's)
2000 Yamaha YZF-R1 (wife's)
1998 Ducati ST2 (wife's)
1994 Suzuki GSX-750R (wife's)
1998 Ducati ST2
1996 Suzuki GSXR-1100
1994 Bimota DB2
1988 MegaPaso 916 project
1987 Ducati Paso 750
1985 Harley FXEF
2001 Ducati M900ie (wife's)
2000 Yamaha YZF-R1 (wife's)
1998 Ducati ST2 (wife's)
1994 Suzuki GSX-750R (wife's)
- Desmo_Demon
- paso grand pooh-bah
- Posts: 869
- Joined: Fri Jul 21, 2006 12:00 am
- model: 750 Paso
- year: 1987
- Location: Easley, SC
- Contact:
Is this as easy as pulling off the sprocket cover, removing the sprocket, cleaning off the area, using a small screwdriver to remove the old seal, cleaning the area again, and then installing the new seal with care not to damage the lip of the seal?jcslocum wrote:The trans uses a splash for lubrication so you won't see a leak until you ride. Just replace the output shaft seal. It's takes about 1/2 hour and costs $8.
2002 Ducati 748 monoposto
1998 Ducati ST2
1996 Suzuki GSXR-1100
1994 Bimota DB2
1988 MegaPaso 916 project
1987 Ducati Paso 750
1985 Harley FXEF
2001 Ducati M900ie (wife's)
2000 Yamaha YZF-R1 (wife's)
1998 Ducati ST2 (wife's)
1994 Suzuki GSX-750R (wife's)
1998 Ducati ST2
1996 Suzuki GSXR-1100
1994 Bimota DB2
1988 MegaPaso 916 project
1987 Ducati Paso 750
1985 Harley FXEF
2001 Ducati M900ie (wife's)
2000 Yamaha YZF-R1 (wife's)
1998 Ducati ST2 (wife's)
1994 Suzuki GSX-750R (wife's)
- Fraser
- Posts: 334
- Joined: Tue Jan 17, 2006 12:00 am
- model: 750 Paso
- year: 1986
- Location: Lower Hutt, New Zealand
Gentlemen,
Thank you for the helpful suggestions. However, in true Ducati tradition it now looks like it is an electrical problem!!
At the rear of the motor, above the swing arm pivot, there is a sensor and electrical cable. Not sure what it actually measures (possibly neutral?) but can now see a trail of oil from where the sensor screws into the motor. Very, very difficult to get to, with insufficient space to get a spanner in to tighten the sensor.
Have put on a new chain though! Thanks for the help.
Fraser.
Thank you for the helpful suggestions. However, in true Ducati tradition it now looks like it is an electrical problem!!
At the rear of the motor, above the swing arm pivot, there is a sensor and electrical cable. Not sure what it actually measures (possibly neutral?) but can now see a trail of oil from where the sensor screws into the motor. Very, very difficult to get to, with insufficient space to get a spanner in to tighten the sensor.
Have put on a new chain though! Thanks for the help.
Fraser.
Aha!
Indeed the neutral switch. And probably it is not leaking at the insert in the engine, but the sensor itself is leaking where the plastic part is
clamped in the metal housing, near the wire connection.
You could try flooding it with break cleaner to degrease it and than put some super glue on the connection, thus sealing it again. I've done this on several sensors and on the crankcase breather, seems to work.
Michiel
Indeed the neutral switch. And probably it is not leaking at the insert in the engine, but the sensor itself is leaking where the plastic part is
clamped in the metal housing, near the wire connection.
You could try flooding it with break cleaner to degrease it and than put some super glue on the connection, thus sealing it again. I've done this on several sensors and on the crankcase breather, seems to work.
Michiel
- Finnpaso
- paso grand pooh-bah
- Posts: 3091
- Joined: Mon Jul 26, 2004 12:00 am
- year: 0
- Location: Finland
That neutral switch is piece of shit. Many have broken and then it start usually leak oil. Need to make suitable tool for changing it, but can be done, cause i have changed some. Remembering, that turning it with tool, U can turn only little by little and thread is quite long... 

Antti http://www.youtube.com/watch?v=HeKOh3XoXPg&NR=1
KTM 990 Adventure -08 metal dark grey
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907IE -91 red/metal grey
907IE -91 red
2xST4S -02 red/metal grey
ST2 -01 red/metal grey
Volvo V70 Bi-Fuel Classic/titanium
KTM 990 Adventure -08 metal dark grey
Paso 750 -89 red/metal grey
907IE -91 red/metal grey
907IE -91 red
2xST4S -02 red/metal grey
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- Finnpaso
- paso grand pooh-bah
- Posts: 3091
- Joined: Mon Jul 26, 2004 12:00 am
- year: 0
- Location: Finland
Still want to know, did that neutral light function normally? Those, what i have changed, that didnt happen, so have to change new one... 

Antti http://www.youtube.com/watch?v=HeKOh3XoXPg&NR=1
KTM 990 Adventure -08 metal dark grey
Paso 750 -89 red/metal grey
907IE -91 red/metal grey
907IE -91 red
2xST4S -02 red/metal grey
ST2 -01 red/metal grey
Volvo V70 Bi-Fuel Classic/titanium
KTM 990 Adventure -08 metal dark grey
Paso 750 -89 red/metal grey
907IE -91 red/metal grey
907IE -91 red
2xST4S -02 red/metal grey
ST2 -01 red/metal grey
Volvo V70 Bi-Fuel Classic/titanium
- Finnpaso
- paso grand pooh-bah
- Posts: 3091
- Joined: Mon Jul 26, 2004 12:00 am
- year: 0
- Location: Finland
Very Good, Fraser
Remembering, that its quite expensive switch... 


Antti http://www.youtube.com/watch?v=HeKOh3XoXPg&NR=1
KTM 990 Adventure -08 metal dark grey
Paso 750 -89 red/metal grey
907IE -91 red/metal grey
907IE -91 red
2xST4S -02 red/metal grey
ST2 -01 red/metal grey
Volvo V70 Bi-Fuel Classic/titanium
KTM 990 Adventure -08 metal dark grey
Paso 750 -89 red/metal grey
907IE -91 red/metal grey
907IE -91 red
2xST4S -02 red/metal grey
ST2 -01 red/metal grey
Volvo V70 Bi-Fuel Classic/titanium