Engine: Oil pressure relief valve location

[Surfpilot]

I would like to pull my oil pressure relief valve on my 6cyl OHV 170 to clean it. I believe I've located it. Is it just under the engine mounting bracket on the same side as the fuel pump? If so, the manual says to use a drill to remove the piston...how is this possible? There doesn't seem to be room for a drill to get in there. Additional question: does the oil need to be drained first before removing the valve?

[Tom Bredehoft]

It says to use a drill bit, which is just a very tiny bit larger than the hole. It screws into the hole then is snug enough that you can pull the 'valve' out.

No to draining the oil.

There might be a bit of 'varnish' trapping the 'valve' in the block, in which case it should be scraped out first, with a pen knife or some such.

[Surfpilot]

So you use the drill bit by hand then? There's no room for a drill motor is what I meant.

[41 Frank]

Yes to using it by hand. The drill bit is just used to get a hold of it and pull it out.

So you use the drill bit by hand then? There's no room for a drill motor is what I meant.

[Surfpilot]

Thanks frank. I appreciate your help. I'll get into it tomorrow.