Whats the hole in the side of the motor for?

[androo]

OK,

I've tried my best to find out what the small hole on the either side of my 250s motor is for, with no joy. Can you help?

The hole is located in the center of the side of the head at around the height of the exhaust.

I only ask this because i've noticed oil leaking from these holes. Is that normal or am i soon to be in for a heap of work?

Thanks

Andrew

[mosquito]

Can you attach a photo or two?

[androo]

I'll see what i can do as far as pics go.

The hole is supposed to be there and is part of the cast, the hole isnt the problem, its the oil coming out of it that has me worried.

[mosquito]

Oil coming out of side of the engine generally isn't normal or a good thing. Really though, people can't make good guesses about the problem or possible solutions without a better description.

It *sounds* like it could maybe be a weep hole or a rocker arm shaft plug but talking about those possibilities is going to be just conjecture and may actually give the wrong impression -- better or worse -- about the situation.

FWIW, I'm not able to quickly find a photo of a motor for you to mark up.

ETA:  Found a photo, but I'm still guessing here.  Do you mean the hole on the far right of this photo, centered on the fourth fin visible from the top? 

  (source)

I have no clue what that is unless it's a core plug (like a freeze plug).  Does it look like it's sealed with a convex disk of tin?  How much is it leaking?

If it is a core plug and it's failing mainly due to age, the proper thing to do would be to remove both / all of them , clean the holes and install new ones.  Still, I dunno what that hole would be.

[androo]

Yes, the hole on the far right of the photo, centered on the fourth fin visible from the top is the hole which is leaking oil.

The leakage only occurs when the engine is running, its not pumping the stuff out, its just a small amount, but enough to notice, a few drops per ride.

Looking at the hole a cant see if its sealed or not, i'll get my flashlight out and check after work and let you know.

Thanks,

[mosquito]

The shop manual for those buggers is tough to find.  I've found one for a GSX250F, GSX-R250, etc., but the best I'm coming up with for the GSF250 is the paatsu katarogu in Japanese in Japan for sale (and there's a bunch of those available in Japan).  Heck, I'd take a shop manual in Japanese or Ainu, for thaat matter.

[tomacGTi]

I would guess that it's a weep hole for around the spark plug wells. The B4 has them drain just under the exhaust pipes and there doesn't seem room on the 250 head for the same.

My guess is that your VC gasket is leaking around the plugs and is leaking out of the holes. I'd replace it because the oil can deteriorate the rubber ends of the spark plug leads.