Piston problems. - Suzuki GSX-R Motorcycle Forums Gixxer.com

 1Likes
  • 1 Post By Modlite21X
 
LinkBack Thread Tools Display Modes
post #1 of 11 (permalink) Old 02-21-2019, 09:57 PM Thread Starter
Squid
 
Join Date: Feb 2019
Posts: 5
Piston problems.

First off, I don't ride a bike. I have an 08 1000 in a dirt car. Running c85, tuned, APE sprockets, and air stacks. Some background into my issue. 2 years ago, I was rebuilding the motor and found 2 burned/melted pistons. They burned right around the valve recesses. Replaced them, ran great, cool. Blew that motor (unrelated issue). Got a new motor, ran it, it's been awesome. Seasons starting in couple months, checked compression, 200 on 3, 105 on 1. Leak down test shows it leaking past piston. Awesome. Ordered new piston and rings. Here's my issue. I pulled the head off tonight, and the piston looks fine. It doesn't look like the other 2 did. Now I'm hesitant to crack this case open to change the piston. I was wondering if anyone else has run into this. I can't see the rings sticking, but I guess it's possible. Any input would be appreciated. Thanks.

21X.
Modlite21X is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old 02-21-2019, 10:15 PM
Likes Diiiiiiiiiiiiiiicks
 
Just_Nick's Avatar
 
Join Date: Jul 2009
Motorcycle: 2006 GSXR "250"
Posts: 3,781
Garage
Re: Piston problems.

Quote:
Originally Posted by Modlite21X View Post
First off, I don't ride a bike. I have an 08 1000 in a dirt car. Running c85, tuned, APE sprockets, and air stacks. Some background into my issue. 2 years ago, I was rebuilding the motor and found 2 burned/melted pistons. They burned right around the valve recesses. Replaced them, ran great, cool. Blew that motor (unrelated issue). Got a new motor, ran it, it's been awesome. Seasons starting in couple months, checked compression, 200 on 3, 105 on 1. Leak down test shows it leaking past piston. Awesome. Ordered new piston and rings. Here's my issue. I pulled the head off tonight, and the piston looks fine. It doesn't look like the other 2 did. Now I'm hesitant to crack this case open to change the piston. I was wondering if anyone else has run into this. I can't see the rings sticking, but I guess it's possible. Any input would be appreciated. Thanks.

21X.
If your ringland is cracked, then it may look fine and not perform fine.
Just_Nick is offline  
post #3 of 11 (permalink) Old 02-21-2019, 10:21 PM Thread Starter
Squid
 
Join Date: Feb 2019
Posts: 5
I suppose. But as bad as it's leaking, I was really expecting something obvious..
Modlite21X is offline  
Sponsored Links
Advertisement
 
post #4 of 11 (permalink) Old 02-21-2019, 11:29 PM
Squid
 
Join Date: Jan 2007
Location: NEW YORK
Posts: 15
Re: Piston problems.

It will most likely be obvious when you pull that piston lol
JUANPSI is offline  
post #5 of 11 (permalink) Old 02-22-2019, 12:30 PM
You should listen to me. No, seriously, listen to me.
 
Join Date: Oct 2008
Location: Santa Barbara
Motorcycle: Blue 2006 GSX-R1000
Posts: 7,250
Re: Piston problems.

How about putting some oil, the thicker the better, into the bore to slow down leaks past the rings and rechecking the compression? Unfortunately that means putting the top end back on.

Any chance that the cylinder wall is cracked? You would have been getting air bubbling into the coolant reservoir if so. Maybe some coolant seeping into the combustion chamber.
BillV is offline  
post #6 of 11 (permalink) Old 02-22-2019, 01:18 PM Thread Starter
Squid
 
Join Date: Feb 2019
Posts: 5
I put the top end back on already just to recheck my readings (again). Same thing. Oil helped but it's still about 50% leakdown. Cylinder walls look immaculate. I'm gonna break it down tonight and see what it looks like. One way or another, I'll know something. I'll keep you updated.
Modlite21X is offline  
post #7 of 11 (permalink) Old 02-22-2019, 06:39 PM Thread Starter
Squid
 
Join Date: Feb 2019
Posts: 5
Good news! Stuck ring was the culprit. Actually the top 2 rings. I'm trying to post pictures but it won't seem to let me.
craigfer63 likes this.
Modlite21X is offline  
post #8 of 11 (permalink) Old 02-23-2019, 12:15 AM
Squid
 
Join Date: Jan 2007
Location: NEW YORK
Posts: 15
Re: Piston problems.

Great news! Did you have the tune checked after the previous piston damage?
JUANPSI is offline  
post #9 of 11 (permalink) Old 02-23-2019, 09:04 AM Thread Starter
Squid
 
Join Date: Feb 2019
Posts: 5
Quote:
Originally Posted by JUANPSI View Post
Great news! Did you have the tune checked after the previous piston damage?
I did. Especially since it was a different motor. Well, same motor, but different motor. Lol. I guess you know what I mean. I'm not sure why they stuck. I thought that kind of thing was a thing of the past but I guess not. At least I know the other ones are good. Less than 2% leak down.
Modlite21X is offline  
post #10 of 11 (permalink) Old 02-23-2019, 12:00 PM
You should listen to me. No, seriously, listen to me.
 
Join Date: Oct 2008
Location: Santa Barbara
Motorcycle: Blue 2006 GSX-R1000
Posts: 7,250
Re: Piston problems.

I'm grasping but I wonder if you have a cooling problem. You presumably already measure the coolant temperature. Do you have a way to measure the oil temperature?
BillV is offline  
post #11 of 11 (permalink) Old 03-02-2019, 03:11 PM
Squid
 
Join Date: Jan 2007
Location: NEW YORK
Posts: 15
Re: Piston problems.

The stuck rings are from the C85 it dries the upper cylinder. I asked about the tune because C85 and E85 timing maps could be tricky to tune. I've seen cars tuned perfectly with it on the dyno only to end up with some knock or detonation on the road which could explain the cracked pistons.
JUANPSI is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Suzuki GSX-R Motorcycle Forums Gixxer.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
'08 GSXR750 Front Caliper Piston part # is wrong? Hawkwind 08-10 GSX-R600/750 10 07-12-2013 11:07 PM
92 1100, broken piston skirt.. cratliff Oil Cooled Gixxers 1 01-06-2013 05:49 AM
Air/Fuel problems badassairman 01-03 600 and 00-03 750 2 06-28-2009 08:17 AM
Problems leading to more problems. Wiring problems PICS!!! sadc 01-03 600 and 00-03 750 17 12-09-2008 11:47 PM

Posting Rules  
You may post new threads
You may 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