bobcat 610 drive sheave balance/fuel tank drain plug size

[Yzracer239]

ive got a 610 and on the drive sheave on the engine, it has an arrow on the outside of the sheave stating to line arrow up with mark on back side. I want to make sure the two balanced halves are aligned correctly. When peering at the backside, as good as I can with the rear counter weight removed, I dont see much. There is one punch mark I see but doesnt appear to be factory, but I could be wrong. Anyone know what the mark looks like and about where it would be? There is also an uneven amount of balancing drill holes between the two halves, should they be split evenly between each other? Also, my fuel tank drain plug snapped off, and I want to drill it out and re tap it, so id like to know the proper plug dia and thread pitch

 

[6brnorma]

Follow the arrow out to the very rim of the sheave……there will be either a straight line (chisel) mark or a "V" shaped mark. There will be an identical mark on the other sheave……match the two up. The "drill" balance holes will not be symmetric. I will get you the info on the plug in a while.

 

[alchemysa]

Follow the arrow out to the very rim of the sheave……there will be either a straight line (chisel) mark or a "V" shaped mark. There will be an identical mark on the other sheave……match the two up. The "drill" balance holes will not be symmetric. I will get you the info on the plug in a while.

On mine, the mark is on the outer edge of inner sheave. Its just little chip out of the metal, smaller than a match head, and easily missed if the metal is dirty.

 

[6brnorma]

On mine, the mark is on the outer edge of inner sheave. Its just little chip out of the metal, smaller than a match head, and easily missed if the metal is dirty.

Plug is 1/4 - 18 NPT