2005 KTM 250 SXF spark plug socket size?

tailgunn
Posts
44
Joined
3/20/2014
Location
Belleville, IL US

I cannot find the right size spark plug socket for this thing. I have no idea if the PO even put in the correct plug, but nothing I have works. I have tried 14mm, 16mm, 18mm, 9/16, 5/8, 11/16. I have even tried regular sockets to just see if the size fits like 15mm, 17mm, and 3/4 won't even fit in the space. The dealer said 5/8 but that's not it. I have looked for thin wall sockets but they don't look any thinner than what I already have. Thoughts?

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9/1/2025 12:05pm

I believe it is a 16 mm thin wall. I have one from Motion Pro that looks like this.1000000876.jpg?VersionId=gXgWwXqFDPIa1000000875.jpg?VersionId=HAviyp4KjV

tailgunn
Posts
44
Joined
3/20/2014
Location
Belleville, IL US
9/1/2025 1:22pm

I guess I'll track down one of those. Thanks.

eeazye
Posts
308
Joined
10/22/2009
Location
Akron, OH US
9/2/2025 8:42am

My 5/8” swivel snap on spark plug socket is the only thing I’ve found that will fit. S9706KFUA is the number. Even the thin wall stamped steel socket that came in the owners kit doesn’t fit. I would imagine snap on’s standard non swivel spark plug socket would fit too, but the swivel is nice with the tank in place. 

Nairb#70
Posts
3560
Joined
2/25/2020
Location
Ivoryton, CT US
9/4/2025 1:48pm

You could always just use an elbatsujda, plenty of room.

1

The Shop

Marty1028
Posts
929
Joined
10/5/2017
Location
Lafayette, IN US
9/5/2025 10:19am

Needs to be a thin wall. 5/8ths sounds right. These years KTM made it a special tool/socket. I took one and had my brother spin it down on a lathe. Fit right in. 

1

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