Go Back   Ducati Forum > Ducati Forum > Ducati SuperSport

Ducati SuperSport Ducati SuperSport Forum


Thanks Tree1Thanks
  • 1 Post By CAT1997
Reply
 
LinkBack Thread Tools Display Modes
Old Jul 15th 2018, 03:38 AM   #1
Junior Member
 
Joined: Jul 2018
From: SYDNEY

Posts: 5
Thanks: 1

1997 900ss oil leak

HI ALL

I Have a stubborn oil leak coming from the vertical cylinder and is also fouling the plug. I have tried to seal the o rings with threebond but its still leaking but not as much as before. i just need some assistance in diagnosing the leak. my thoughts were the oil dowel because when i first changed the o rings i noticed bubbling around there but now im not so sure.

i have attached some photos. do you think i could get such a leak from worn piston rings.
Attached Images
File Type: jpg 20180705_162501.jpg (83.8 KB, 15 views)
File Type: jpg 20180705_162744.jpg (81.9 KB, 12 views)
File Type: jpg 20180705_162753.jpg (76.1 KB, 14 views)

Last edited by CAT1997; Jul 15th 2018 at 03:53 AM.
CAT1997 is offline  
 
Old Jul 15th 2018, 04:49 AM   #2
Member
 
Joined: Feb 2017
From: Colorado

Posts: 46
Thanks: 5

I Ride: 2015 899 White
I'm not familiar with this particular engine, but an engine is an engine right lol. Based on the carbon build up on the piston I would suspect your valve seals and valve guides are done for, particularly the exhaust valve as that's where the most build up on the piston is. I don't think rings would cause this unless they're massively worn. Was there much blowby coming out the crankcase, or fuel dilution in the oil? That would be a sign your rings and or cylinder are shot. The oil dowel leaking would only be external to the engine as it would have to get passed the head gasket to enter the cylinder. Hope this helps! Also if it is your valve seals that are leaking by its most likely leaking the most while the engine is off, is there noticeable smoke from the exhaust at start up? Again good luck with your diagnosis!
AaronJ is offline  
Old Jul 15th 2018, 06:05 PM   #3
Junior Member
 
Joined: Jul 2018
From: SYDNEY

Posts: 5
Thanks: 1

ive already changed the valve seals and check them when the heads were off so i dont think its that. ive had a valve seal fail before and it clogs it up pretty quick. also there is no smoke whatsoever. the bike runs really well other than this odd leak.

how do i detect blowby? also this doesnt have a head gasket it has a set of o rings.

if you take a look at the pics you can see carbon on the rim next to the stud and also oil around the rim.

i was also told by my mechanic as you have stated that oil couldnt get through to the piston from the oil dowel.

maybe the valve guides....
CAT1997 is offline  
Old Jul 16th 2018, 09:55 AM   #4
Member
 
Joined: Feb 2017
From: Colorado

Posts: 46
Thanks: 5

I Ride: 2015 899 White
The carbon on the sealing surface definitely looks like there is a small leak between the head and cylinder. IF you can find specs for what the factory considers normal blowby you can build a manometer (google it its very easy all you need is a length of clear tubing such as tygon) and hook that to your crankcase vent and measure the crankcase pressure in inches of H20 while the engine is running at idle at operating temp. I'm somewhat doubtful you will find specs but I may be wrong. Another option would be to do a compression test or a leakdown test. You can find the tools at harbor freight (not sure if you have these stores down under) fairly cheap. That will tell you for sure if you have valves or rings leaking by. An easier but not specific way is just remove the oil fill cap running at operating temp and see if its blowing a lot of exhaust, oil vapor etc out of the fill port. Finally, if the valve guides are worn badly they will take out the valve seals fairly quickly.

What kind or o-ring seals the head? Is it a rubber or Viton compound or something more rigid such as a copper o-ring?
AaronJ is offline  
Old Jul 16th 2018, 12:52 PM   #5
Junior Member
 
Joined: Jul 2018
From: SYDNEY

Posts: 5
Thanks: 1

I did a blowby test last night by just having the filler cap sit on the crank unscrewed and it blew right off so the leak is caused by excess pressure in the crankcase. Im looking into the crankcase breather which looks rusted and has condensation but I need to get it off. I dont know how these reed valves work but when I accelerated I didnt really feel or see additional movement of air. Next I will do a compression rest because of its not the breather it must be the rings.
Thanks for your ideas it really pointed me in a new direction amd diagnosed the crankcase pressure and cause of the leak. Hope its the breather.

There were no apparent gases other than what I could smell as being only oil. The engine was cold whe I tested but the oreasure does see high. There is no smoke coming from the exhaust or into the intakes ie clean air filter. Need to perform a leak down test

You know i looked at what blowby is on youtube and is see no gases on mine. its clean. just the filler cap blew right off.

i do have a fouling plug on the vertical only but i thought maybe its because of the leak seeping through.

i guess i need to get a leak down test done.
Thanks from AaronJ

Last edited by CAT1997; Jul 16th 2018 at 11:15 PM.
CAT1997 is offline  
Old Jul 30th 2018, 10:25 PM   #6
Junior Member
 
Joined: Jul 2018
From: SYDNEY

Posts: 5
Thanks: 1

900ss Piston Ring Clocking

Hi All

im about to change my pistons and rings on a 97 900ss and the manual says to clock them at 120 degrees of each other but it doesn't mention a starting point.
does it matter where to start?
CAT1997 is offline  
Old Aug 3rd 2018, 03:10 AM   #7
Member
 
Joined: Feb 2017
From: Colorado

Posts: 46
Thanks: 5

I Ride: 2015 899 White
Sorry I haven't been on lately. I wadded up my 899 a couple weeks ago and have been busy finding parts lol. I assume your leakdown test came up bad. No it doesn't matter, you can start at any position you like.
AaronJ is offline  
Reply

  Ducati Forum > Ducati Forum > Ducati SuperSport

Tags
1997, 900ss, leak, oil



Thread Tools
Display Modes


Similar Discussions
Thread Thread Starter Forum Replies Last Post
Oil Leak Desmobill Ducati 1199 17 Oct 15th 2014 09:55 AM
Another Leak! YES! danamite14 Ducati 1199 17 Jun 4th 2014 07:58 AM
Possible Oil Leak korym Ducati 1199 3 Sep 22nd 2013 03:31 PM
A leak somewhere ? jamie1991 Ducati 1199 8 Jun 9th 2013 02:51 PM
Oil leak Torquesp New Users 7 Jun 5th 2012 08:40 PM


Facebook Twitter Google+ RSS Feed