| Author | Message | ||
     Wolk625 |
So it's looking like I'm going to need to replace my rear head gasket - got quite a bit of dribble coming out around it and some light smoke at full temp.. I have the full shop manual and an upbeat attitude, but am wondering what all else I might encounter along the way - what specialty tools will I need (if any) for the head bolts? What else should I check/consider replacing on my way down in there and back? Is it even something I should be able to handle or leave it to professionals to do? | ||
| Kilroy |
Make sure is isn't your rocker box gaskets that are leaking and making it appear to be your head gasket. Could save you a lot of effort, and they are notorious for leaking, especially if they are still the originals. | ||
| Firemanjim |
As a rule the head gasket will not leak oil, look at rocker boxes and pushrod seals . | ||
| Wolk625 |
I know for fact that the bottom rocker gasket is good, because that was the first thing that I replaced when I noticed the wet spot months ago, and that this spot is smaller and lower than the first one. The oil spot starts below the rear exhaust port and down - everything above that is dry. If it were the pushrod seals I would think I would see more oil in the area of those seals but those seem pretty clean. Would it be possible for oil to get pulled into/past the exhaust valve shaft and be expelled in the exhaust, and what I may be seeing is oil from that seeping through a bad rear header gasket seal? What else could explain my smoke? | ||
| Oldog |
FMJ covered it, the standard box is 3 pieces so look close. IMO a valve guide seal will not show up outside in most cases and would smoke like the dickens, the OIL return hole is near a corner of the jug Sorry I had pix of the top end job i did some time back and was going to post up but I can't find em, Looking at a damaged jug I keep as a book end, there is an oil passage on the front jug, If you are facing the motor at the front of the bike its on the front right corner of the jug,(opposite the push rods) the oil passes thru an oring-ed dowel down thru the base gasket into the bottom end, It seems like its on the wrong side of the motor. Ymmv | ||
| Wolk625 |
Just going to share what I am seeing - may or may not help some:    When the rocker box was leaking it was obvious with the oozing from the bottom of it, but this leak has been present before and after that one. I am beginning to fear if this is a sign that my piston rings are going bad and that's how I've got oil coming from there.. | ||
| Essmjay |
Yep. Head gasket. Doesn't mean your rings are bad though. If it was me, with riding season here, I would just pull that head and remove the jug with the piston enclosed. (Pull the wrist pin and remove the jug and piston together). You will have to replace the head gasket and base gasket but you should be able to reuse the rockerbox gaskets. You can visually inspect the bore and piston and if it looks okay, put it back together. Then next winter you can think about going through the whole top end. Do not attempt to only replace the head gasket, you will only find the base gasket leaking shortly after you put it back together. | ||
| Bluzm2 |
What Shane said... | ||
| Kevmean |
Or before you tear it to pieces just try retorquing the head bolts and see if it cures it (it did on my X1  | ||
| Reepicheep |
Why mess with the circlips and wrist pin? Seems easier to just pull the jug and leave the cylinder in place. It's not that hard to get the rings back in place and into the jug. I'd be nervous re-using circlips, and they are a hassle to get in and have confidence that you got them in trying to put them in with the jug in the way (in my limited experience). | ||
| Purpony |
I left the cylinder in place and just pulled the jug... Was very easy to slide the piston/rings back into the jug. I borrowed a friends piston/ring tool and didnt even use it. Always replace your base gasket when you do a head gasket. It was a pretty straight forward easy fix. | ||
| Essmjay |
The reason I would leave the piston in the jug for this job is that the existing rings have worn into the cylinder wall. If you pull the piston out the rings will never line up again with the existing lands and grooves. (You may not be able to see them, but they are there.) If you pull the piston out you should at the very least run a hone through the cylinder before reinstalling the piston. At that point you may as well do it right and just do a full top end job with new rings and a cylinder bore to match. but if you just want to get onto the road with minimal cost or wear and tear, leave the piston in place. You can easily buy new wrist pin circlips, in fact you should never reuse those little buggers. | ||
| Oldog |
Yes head gasket leaking at the oring I would change it out, the gasket is going to fail completely at some point, You might try the re-torque nothing to loose except some time.... | ||
| Wolk625 |
My eventual goal was to replace both head and base gaskets eventually at some point but it's looking like I should be looking into that a lot sooner than I originally planned. Both ideas for the piston do seem to have good reason why to do it that way, so my end decision will probably be made when I can pull the head and assess what I'm working with. For this "re-torque" being mentioned, is this similar to the manual's technique of - torque once then completely un-torque then re-torque again, or is it simply cracking the bolts loose then re-tightening to spec torque? Thanks for all the responses guys. | ||
| Jolly |
my S3 just started leaking at the base gasket rear cylinder...fun! grrr looks like Im in the same boat as you..and here we go down the rabbit hole, this motor has a fresh rebuild from the last owner but it does not have the xb rocker box conversion so now I've got to do a base gasket and the xb conversion;. let me know if you ended up pulling the cylinder with the piston in or if you just pulled the jug and re-inserted the piston? I would not have thought that the rings seating would have made that much of a deal on these bikes to be concerned with it after the motor is broken in and your re-inserting the same piston and rings (not worn out)... |
