Countersunk Screw

I'm sure you see a few ideas here as people post.

You may need to remove the carb to get it out. I always tell folks not to over tighten these top two screws. When I take these two screws out I use a 1/4" ratchet with a phillips head tip. I can put a lot more downward pressure in the screw head to keep it from stripping. I have had a few that wouldn't come out. Those I remove the carb and take my small butane torch and heat all around the outside housing the screw is in. This usually works. If the screw head is really stripped see if you can put a slot in the top of the screw with a Dremel tool and a cut off blade, I have used this technique for decades and usually works just fine.  Heat it up and use a straight tip screwdriver to remove it. I try to stay away from drilling because that may damage the housing and its threads. 

Hi Sean, assuming that product data is correct in a Rotax parts online shop the screw follows DIN966. That makes it A4 stainless steel. M5 has a pitch of 0.8. 

There is no hint regarding a fine thread which would have a pitch of 0.5.

Thanks for that Peter Kl,

You are absolutly correct. I've just come back from checking  with a thread gauge 0.8 .

I am wondering why these chamber screws don't have Allen Key/Cap Screw heads.? 😈

Hi Sean,

Peter KI is right, you can use any other screw of DIN966 A4 with a countersink head you prefere, If the screw is still in the carbhousing, i would take a tiny screw extractor tool. Greetings.

Personally I try to avoid any drilling . I see so many destroy the treads or housing.