At this stage of my engine repair, I am installing the head plug.  The Clymer Manual says not to use a sealant - but the repair thread on this forum recommends sealant.  I cleaned up the head and plug to remove any traces of oil, then applied a small amount of SuzukiBond, then installed the plug.......and it popped back out of the hole!  I tried both the new factory plug and the original one....and they both did the same thing.  This tells me that the plug really doesn't want to stay in the hole....the way it is made results in it wanting to come out of the hole.

I made a small clamp to hold it in while the sealant sets.....but this tendency of the plug to come out of the hole has me wondering if it needs a bit more to secure it.

The head cover has a flat aluminum surface just above the plug, and it would be possible to install a rubber stopper or a spring to put a slight amount of pressure on the plug to prevent it from working out over time.  I would trim the rubber plug or get a spring of the correct length to apply just a small amount of pressure - not enough to try and push the plug through the hole.....just enough pressure to keep the plug seated.

Anybody got thoughts on this one?

I tried both the new factory plug and the original one....and they both did the same thing.  


If both the old & replacement plugs look the same & act the same, ehhhh,, probably not a defective part,

Others have done this job, has anyone seen it do this?


Feel the hole it goes into, are the walls a cylinder or a slight funnel shape?

How many miles on it before it leaked?



The head cover has a flat aluminum surface just above the plug, and it would be possible to install a rubber stopper or a spring to put a slight amount of pressure on the plug to prevent it from working out over time.


I think thats a lovely solution. Use sealer & put some pressure on it so it doesnt move,

Yep......I am learning about this bike.  The lessons and learning came a little faster than I had wanted!

I read through the head plug tech article, and the one thing that I didn't get out of it, was that this plug is seemingly unstable.  I first juts pushed the plug into the hole for a test fit....and the friction made it stay.  When I applied the SuzukiBond sealer.....which is a slippery silicone sealer when it is fresh - it lubricated the plug and the darn thing would pop right back out without the dry friction to hold it.  It seems to me that the plug should want to stay in the hole......not come back out!  It may be those leaky plugs that people have blamed on the technicians not getting in correctly may have popped out on their own.

I did decide to put a rubber stopper that I trimmed to length into the plug.  I trimmed it so that it sits about 1/16" taller than the seam between the head and head cover, and I used the SuzukiBond to secure it into the plug.  I then cut a small round piece of electrical tape and made a dot the size of the top of the rubber plug so I could prove to myself where it would push on the head cover.  When I temporarily put the head cover back on, the black dot stuck to the head cover to indicate where the stopper would rest.  It pushes on the head cover near the hole where the bolt for the rocker shaft bolt is located.  The rocker shaft bolt does not come down out of the head cover - so the rubber will be fine in this location.

This is the rubber stopper trimmed to fit the height of the plug.  It is hard for me to photograph black on black....but the plug is about 1/16" taller than the joint where the head meets the head cover.


This is where the rubber stopper will come to rest.  There is just a slight pressure to keep the plug from coming up out of the hole.


Is this necessary?  Well a lot of these plugs have failed for some reason - and I sure do believe that the plug is not designed in a way that locks it into the hole.  I feel better having done this.....but it may not be something everyone buys into.

OF.....I pretty much have relied on the Clymer Manual for this tear down and rebuild.  I really didn't feel qualified to do a photo essay of it......maybe on the next one!

This is where I am tonight.  The cam has to be installed, then the head cover and rocker arms, then the tensioner, then both covers.  After that it goes back into the bike and the starter, carb, exhaust....etc.  I have meetings Monday, Tuesday and Wednesday night....so it will probably have to wait until next weekend for another work session.

I use the red RTV stuff on the plug, both old and new type; tapped it down with a deep socket; it did not move after that

no runs, no leaks, no errors

Now that would be a piece of progress .....

renegade1 wrote on 08/13/12 at 10:07:12:


Well that is a good question.......long enough for the sealant to cure!  Once you get the engine taken apart, the plug out, everything cleaned up, the plug siliconed and pushed in, the head cover sealed and attached, and the rest of the engine back together......I imagine you are going to want to go to bed and get some sleep and it will cure overnight.

OF and Serenity did this job on the Dragon Trip in about 3 hours total if I remember correctly.......and they let it sit for a couple of hours before the test ride.  It worked fine.

...... stick a boat transom bung in it from the bottom and twist the tit until the bung gets plugged.



Problem, what happens to the old plug that is still loose up inside your head?