Leaking crankcase gasket - Kawasaki Z125 Forum
 1Likes
  • 1 Post By Greg_E
 
LinkBack Thread Tools
post #1 of 10 (permalink) Old 08-18-2019, 10:03 PM Thread Starter
Member
 
jwiseman's Avatar
 
Join Date: Oct 2018
Location: Newtown, PA
Posts: 51
Leaking crankcase gasket

My 2017 Z with 1500 miles has developed a crankcase gasket leak on the top of the engine. Not terrible (yet) but definitely noticeable after a good ride with an engine workout. I clean it off and check after every ride and itís definitely leaking, less so putzing around town. Bike has the 143cc TB top end, cold air intake, Graves pipe. These mods have been running fine the last 1000 miles. Tried loosening and retightening the 2 upper case screws and motor mounts. No luck.

Anyone have experience with a leak like this, stock or modified? The cases have not been split on this bike.

Hadnít planned to split the cases, but itís looking like a necessary winter project. Guess if nothing else it will be a good excuse for a stroker crank...

JW
Attached Thumbnails
Click image for larger version

Name:	CEFDA423-4C00-49D9-85A2-267E9CFCBEE2.jpg
Views:	33
Size:	110.3 KB
ID:	23743  
jwiseman is offline  
post #2 of 10 (permalink) Old 08-18-2019, 10:33 PM
Senior Member
 
Greg_E's Avatar
 
Join Date: Mar 2018
Posts: 843
Garage
Could that white line be a crack?
Kawasaki Brad likes this.

My site:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Youtube channel:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Greg_E is offline  
post #3 of 10 (permalink) Old 08-18-2019, 10:45 PM Thread Starter
Member
 
jwiseman's Avatar
 
Join Date: Oct 2018
Location: Newtown, PA
Posts: 51
Quote:
Originally Posted by Greg_E View Post
Could that white line be a crack?
No, that is likely a reflection of the camera flash in the oil streak. That is not visible when looking at it directly.

JW
jwiseman is offline  
 
post #4 of 10 (permalink) Old 08-18-2019, 11:13 PM
Senior Member
 
Kaw'ee's Avatar
 
Join Date: Dec 2017
Posts: 1,587
Garage
Seeing lots with slow oil leaks in front at the notch in the case, But haven't seen any where you showing.
.
Guessing you defiantly ruled out it's not coming from the vent hose and running down and showing up there
Not much of a spring clamp on it.
.
.
Attached Thumbnails
Click image for larger version

Name:	67538933_162435061585772_7905400458095624192_n.jpg
Views:	24
Size:	22.3 KB
ID:	23745   Click image for larger version

Name:	s-l1600 (3).jpg
Views:	26
Size:	218.4 KB
ID:	23747  


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Kaw'ee
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by Kaw'ee; 08-18-2019 at 11:17 PM.
Kaw'ee is online now  
post #5 of 10 (permalink) Old 08-19-2019, 10:26 AM
Senior Member
 
Greg_E's Avatar
 
Join Date: Mar 2018
Posts: 843
Garage
It looks like it is the case between the two engine mounts, is this correct? Not the area circled in the picture above. Looking at the casting it shouldn't even have oil in it right in that area (blocked off by a web on both sides).

My site:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Youtube channel:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Greg_E is offline  
post #6 of 10 (permalink) Old 08-19-2019, 10:50 AM
Senior Member
 
Kaw'ee's Avatar
 
Join Date: Dec 2017
Posts: 1,587
Garage
Quote:
Originally Posted by Kaw'ee View Post
Seeing lots with slow oil leaks in front at the notch in the case,
.
.
Ya, pic was for front leak most seem to have
I have light mist leak there on mine all the time as well
Attached Thumbnails
Click image for larger version

Name:	67538933_162435061585772_7905400458095624192_n.jpg
Views:	11
Size:	22.3 KB
ID:	23749  


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Kaw'ee
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Kaw'ee is online now  
post #7 of 10 (permalink) Old 08-19-2019, 10:51 AM Thread Starter
Member
 
jwiseman's Avatar
 
Join Date: Oct 2018
Location: Newtown, PA
Posts: 51
Quote:
Originally Posted by Greg_E View Post
It looks like it is the case between the two engine mounts, is this correct? Not the area circled in the picture above. Looking at the casting it shouldn't even have oil in it right in that area (blocked off by a web on both sides).
The crankcase pix were very helpful. Hereís my arrow added to show where Iíve isolated it to. Anybody experienced a low-mileage leak in this area?

JW
Attached Thumbnails
Click image for larger version

Name:	D8076115-1D7D-431A-9070-97EC3D140016.jpeg
Views:	18
Size:	252.2 KB
ID:	23751  
jwiseman is offline  
post #8 of 10 (permalink) Old 08-19-2019, 05:47 PM
Senior Member
 
Greg_E's Avatar
 
Join Date: Mar 2018
Posts: 843
Garage
I would check the torque on those two bolts and see either is loose. After that you either live with it until it gets worse, or tear the cases apart and check for warping. I would use Hylomar in that area to try to seal off any non-flat areas, either that or find a shop that can fly cut or surface grind the cases (but only a little or things will get wrecked). I'd be willing to guess that 0.010 inches is the maximum that could be removed, and it could be less than that wich doesn't give a lot of room to fix things.

My site:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Youtube channel:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Greg_E is offline  
post #9 of 10 (permalink) Old 08-19-2019, 10:43 PM
Senior Member
 
Join Date: Feb 2016
Location: SoCal, USA
Posts: 145
Quote:
Originally Posted by jwiseman View Post
The crankcase pix were very helpful. Hereís my arrow added to show where Iíve isolated it to. Anybody experienced a low-mileage leak in this area?

JW
I've seen various crankcase leaks over the years on all brands of bikes and if they are located on the top of the cases you can often just get by with applying a little extra case sealant right over the leaking sealant. There is no fear of a large leak up there, it's just oil mist seeping through, often due to a small gap in the factory applied sealant. So don't get all worked up about machining your cases just yet because once it's sealed you can usually wait until winter to split the cases and find the actual cause. And then add your stroker crank.
Lobot is offline  
post #10 of 10 (permalink) Old 08-20-2019, 10:47 AM Thread Starter
Member
 
jwiseman's Avatar
 
Join Date: Oct 2018
Location: Newtown, PA
Posts: 51
Quote:
Originally Posted by Lobot View Post
I've seen various crankcase leaks over the years on all brands of bikes and if they are located on the top of the cases you can often just get by with applying a little extra case sealant right over the leaking sealant. There is no fear of a large leak up there, it's just oil mist seeping through, often due to a small gap in the factory applied sealant. So don't get all worked up about machining your cases just yet because once it's sealed you can usually wait until winter to split the cases and find the actual cause. And then add your stroker crank.
Thatís my plan! Winter project it is...

JW
jwiseman is offline  
Reply

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome