Oil drain bolt thread size - '00 CR250

[cr250john]

It appears that a piece of foreign material is stuck in the upper couple threads where the oil drain bolt screws in on my '00 CR250.

The bolt is a 12mm diameter but I'm not sure of the threads per mm. I measure about 1.5 threads per mm but I don't want to use a tap in the hole until I make sure I have the correct one.

Do you know the correct bolt/tap pitch?

Any help is appreciated!
Thanks!

 

[biglou]

John-I know this won't be much help, but I can say with about 99% probability that it is either a 12mmx1.5 or a 12mmx1.75.

I just went through this debacle with a 99RM250 and it is the rare bread of 12mmx1.25. Scarce as hens teeth, that size is.

 

[SFO]

If you take your fastener to a machine shop or a auto shop they should have a thread pitch gauge you can measure the thread pitch with.
I would suggest using a forn tap to chase the threads as it will not make chips as it forms instead of cuts the threads.
I always use forms taps when rebuilding my motors makes for a very tidy job.

 

[cr250john]

I was able to find a person with a metric pitch gauge and it is 12x1.5mm.

Called around and found the tap at a NAPA auto parts store.

SFO - Your right - I don't need to cut new threads, just "chase" the old ones.
Sometimes using a LOT of grease on the tap also helps catch any chips that may come off.

Thanks again to all!