Cylinder play/tightness

Well my desktop computer crashed with a virus as I was trying to post this last time so I'll just keep it short and sweet this time...

I was removing the head from my 1998 wr400 when I noticed that as I pulled up on the cylinder a small (1mm or so) gap appeared at the bottom of the cylinder on the right side opposite the bolt that holds it on. As soon as I release my grasp the gap went away. I was pulling to move the exhaust over as the nut on the exhaust was just spinning the threaded rod it was on, and I needed to take the head off before I could get it off anyway.

Here are my questions: Since only one bolt holds the cylinder on, is this gap normal? Should I replace the bolt as a precaution to the fact that my pulling could have weakened the bolt and that it might break later down the line? If I replace the bolt, should I replace the gasket too?

I'm a little paranoid when it comes to the small things, and I don't have the time or money to pull the head again should I get it back together and something is wrong with the cylinder.



Surely someone has had their motor apart and noticed this or has worked on enough motors to know the answer.

Talked to my local shop and they said that it was normal but that I should definitely replace the gasket should anyone find this post in a search and want an answer. Is it possible to remove the cylinder and compress the rings by hand to put it back in, or do I need the tool?

Got my '06 in by hand, no problem, don't understand " one bolt ", my bike has one bolt each side, as I remember. Always replace gaskets.

This cylinder is only held on by one bolt on the left hand side, and this is confirmed by the manual. As it sits, I can push down on the right side and close the gap that is at the base of the cylinder. I'm wondering if a new gasket will change that or if it is normal? Nothing leaked before, but I'm not sure how that the cylinder is suppose to get a tight seal with only one bolt? I might as well pull it apart and replace the gasket since I have it this far apart anyway. I'm inclined to get a new bolt as well...

Thanks for the insight,


On something like a cylinder, you need to tighten both all sides in a cross-cross pattern as well as removing them the same way in stages. Manual should indicate this as well to stop warpage and create a correct, even seal.

Never fully loosen a sealing bolt whole leaving the opposite one fully tightened. Hopefully if this is what you are describing there is no permanent damage done.


Mine's an 06, sorry.

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