Cylinder Head Hole

[mglowe]

Just curious... anyone know what the purpose of the small un-threaded hole in the cylinder head on left side of engine is for?

The service manual [Service-LIT-11616-20-60] diagram on page 5-19, 5-20 and 5-21 shows this hole so its suppose to be there.

 

[wrightme43]

usually they are for draining water from rain out. This is without looking at it, just thats what they are usually for.

 

[trailblazer87]

Yep, just a weep hole.

My suzuki has one as well.

 

[Wildcat_drvr]

I did a search about the "hole in the head"and found this thread. How does this "rain water" get in the engine? I wonder what that hole is really for as I have doubts about the "rain water" answer. Anybody got a better idea as to it's purpose? Rich,, PS: I know this thread is old but it's the only one I could find. And please don't say the rain water comes from rain. LOL Thanks!

 

[Wildcat_drvr]

Just bumping this thread. Thinking (I know, that's dangerous) that maybe this hole is used to hold or "index"the head while being machined? Rich and,, Why isn't it painted inside.

 

[Esra]

Isn't this to allow the water produced during combustion to escape.

Nothing to do with rain.

 

[Wildcat_drvr]

I would think that anything produced by combustion would have to be contained somehow due to emission regulations? I thought the S-2 was built to Euro 3 standards? Rich,, PS: Water blows out of my tailpipes on start-up, but it has been through the Cats.

 

[thieu]

Some - a very small amount - can come down towards the spark plugs. If there was no drain you could imagine what would happen over time!

 

[iSteve]

I just thought it was something from manufacturing. I can't imagine any water touching the head or cylinder area not steaming off. And don't see any way this could connect to the top of the head near the plugs.

Now I got to go out to my bike and take a look at it.

 

[FinalImpact]

Isn't this to allow the water produced during combustion to escape.

Nothing to do with rain.

Not a chance on this one.....

 

[iSteve]

Just looked at it, bigger then I thought. The plug drainage now seems likely and maybe even could indicate if a seal is leaking.

 

[FinalImpact]

It makes sense that it could be used to let water drain from the plug wells as it would have no other means of escape. If the head only reaches 200F of some days it could take while to evaporate and it would likely cause arc-over/electrical shorts at the plug and cap if full so its a "could be" in my book.

I believe there is another thread or 7 on this topic elsewhere....

 

[MagicMANX]

thats weird, never seen the "hole", as soon as I get home will look at the head and examine it xD. If someone finds out what's it for, please post

Cheers!

 

[Sawblade]

 

[abraxas]

I can answer this!!! (having a spare cyl head to inspectigate)

It's a weep hole, that runs along the body of the head, with small holes that sit on either side of the spark plugs. If the head is off, you can see all the way through. It is completely sealed and separate from the oiled parts.
It's to allow moisture out the spark plug holes, any that manages to get under the plug caps. Obviously when the engine heats up, the moisture evaporates and is able to escape.

If you ever feel air movement out that hole, you're about to have a bad day!

Check spark plugs.

 

[FIZZER6]

I can answer this!!! (having a spare cyl head to inspectigate)

It's a weep hole, that runs along the body of the head, with small holes that sit on either side of the spark plugs. If the head is off, you can see all the way through. It is completely sealed and separate from the oiled parts.
It's to allow moisture out the spark plug holes, any that manages to get under the plug caps. Obviously when the engine heats up, the moisture evaporates and is able to escape.

If you ever feel air movement out that hole, you're about to have a bad day!

Check spark plugs.

Thank you for finally putting this to rest. I have seen moisture weep out of this hole once and was a bit concerned that it was an oil leak. Now I know it's just moisture evaporating from the spark plug tubes. :thumbup: