I have a 2011 with the police style MC Enterprises guards that I need to remove. It came with an oversized m12 bolt for the lower bolt on the left front engine mount. It should have come with an m10 as far as I know.

I have a new engine mount bracket and I ordered what I thought should be the correct m10x45 bolt to see how the original fitment was like. This bolt has lots of clearance. It almost seems like the bolt is too small since the fit is pretty sloppy. I need to drill out the engine bracket for the m12 bolt and I wonder just how much clearance this bolt should have. I can't tell based on the old bracket because the hole is a bit oblong.

My thought was to keep the clearance pretty tight, but the bolt I got to check the original fitment was really sloppy so I thought I would ask.

 the 10x45 bolt is what I see on the fiche....
did the p/o re-tap the engine where that bolt attaches, to M12 ..?

thats really a bummer if so... sounds like they jacked the thing, and stripped the bolthole during the install because they didn't allign it properly..
personally, if they did retap it, I'd consider finding the data for using a heli coil insert, and returning it to 'correct'. Check the actual threaded hole in the engine, then research the tap size they use for the helicoil insert, they sell them at AutoZone.

They did retap the engine to M12 and also must have enlarged the engine bracket clearance hole.  The engine hole is already too big for a standard heli coil.  I looked into it again and the oversized heli coils or time serts would work for this. The kits look fairly expensive though.

I took some measurements of the m10 bolt. It is about 9.85 mm. The hole on the engine bracket is about 11.9 mm with the center piece of flashing being about 11.2 mm. That looks like it would require a loose fit clearance hole if I choose to keep the M12 bolt.

I now see that the upper bracket bolts should have collars. They didn't have collars installed when I removed the bracket. Is there any legitimate reason why the collars would have been removed or not installed in the first place?

I did do some more measurements on the clearance hole. Normal clearance looks to be about 13.5 mm or close to 17/32nds. The old hole is smaller than that. I think it was 1/2" so that is pretty tight clearance.

I don't know if any of this was done on purpose. Man of Blues is probably right about it just being jacked up on accident. I was thinking it was part of the design of the police bars installation.