Topic: cb650 Head Bolt Tap to clean head bolt holes out and other ?'s

[ts354]

1981 CB650 (not a Custom)

I took the head and cylinders off to put new gaskets in and clean all the carbon out of the ports and combustion chambers as well as off the valves, cylinders and pistons.  I plan to hone the cylinders and re-ring the pistons.  I guess that doesn't have any real relevance on the questions I have.
 
My questions has to do with the head bolt hole threads. (CB650's have head bolts not studs)
a. What tap (if any???) should I use to chase out the dirt and crap out of the holes?
b. When installing the head back on, what should I apply to the head bolt threads?  Anti seize, motor oil, Marvel Mystery Oil, or nothing. 

Thanks,
Todd

[bryanj]

For tap size you need to measure the bolt for lubricant consult the manual

[Nicklopic]

I recently cleaned the threads on mine. I used a standard plug tap covered in grease to catch debris because a few had some holes going down all the way through due to a previous owner overtorqueing. Thread size is 8x1.25.
Can't say about the second part as I have not read my manual for assembly yet.
Be sure to clean any and all debris and dirt from the bottom of the wholes or it will blow out the bottom of the threads when torqueing the bolts down

[DaveBarbier]

Measure the head bolt size and use that tap to clean out the holes.

Manual says use moly (molybdenum disulfide grease) on the head bolts and under the washers.