"Since I am in there" I decided to clean(sandblast and paint) my fan. In order to get it extra clean, I took it apart. Well three of the 4 bolts came out. M8 triple square wrench slipped on the last bolt and stripped it. I drilled it out, but now I am 1 short. Those damn things are 1 of a kind....M7 x 1.0 x 55mm low profile socket head (triple square or 12 point socket) no where to be found. Even AA has the wrong size and quantity. they say the things are 45mm long and there are only 3 of them.

I guess I can change all 4 bolts & nuts to M8 allens or 1/4-20 or 28, or buy a new fan. Anyone have a source for 7 mm hardware or a ruined fan that they will pull the bolts for me?

thanks,
Clark

It's not a good idea to take the fan pulley off the fan as it's balanced at the factory. You can't just put it back on or the motor will feel lumpy at higher rpms. I know the bolt you mean, and the head is pretty tight in the groove there to put bigger ones in. 1/4" is 8/32, 7mm is about 9/32 so, well I wouldn't do that anyway.

Don't ask me how I know

I had read that about the pulley. so I marked it to be returned to it's original position. I should be OK on that.

The M8x45 are for holding the fan on the end of the crank, not for holding the fan together.

There is enough play in the holes in the pulley to make a difference even if it's in the same holes as it was. I can see variation in how close the square nuts are to the lip on one I've got. I think they put the weights in the lip of the pulley after it's assembled.
You can have a machine shop do it for you. I've got one that I need to have done also.

I did that without having it rebalanced, but mine way WAY off after I put it back together. It ended up shearing the bolt that holds the fan to the hub and stripping the woodruff key out of my crankshaft. Not a good thing to have happen when you are halfway through a 2500 mile roadtrip.

-Ross