Drilling for subtanks

I am currently installing the subtank system described by Shawn_MC (on an 03 CRF450.) (Thanks Shawn_MC for the information.) I have some questions concerning drilling and tapping for the 1/8 NPT fittings.

Do you drill all the way through the bleed hole (or just deep enough for the fittings?)

Do you separate the cap from the spring/washer etc. before drilling (or just be careful and clean after drilling?)

What about the spacer on top of the spring? It currently covers part of the bleed hole? Did you trim this at all?

Finally, is the hole very close (after you drill) to the edges of the cap? It appears that there is going to be very little metal left after I drill.

Any help is appreciated. Thanks.

I imagine he is using the 1/8" npt tap, right? If so, drill all the way through. That tap has a major taper to it. It will extend all the way through the bleed hole as your threading the hole you drilled.

The washer under the bleed hole covers part of the hole, not enough to matter.

The material gets real thin, go easy and make sure you are centered. Use teflon tape on it to seal and don't overtighten.

Take it apart to drill! You don't want metal shavings and what not in your cartridge oil!!!

Mine is flawless so far. :)

Pirates! :)


Pirates? Imitation is the . . .

Thanks for the quick reponses.

One more question to futher clarify. I have removed the caps from the cartridge. Do I need to separate the cap from the IC spring/assembly before drilling? Seems obvious that I should, but just wanted to verify.

Again, thanks for the help, not just this thread, but all of the previous on the subtanks, airboxes, valves, etc.


Still at it I see.

How many have we done now? :)

Must be something to our system.

BTW: I used the red pneumatic tubing with the quick-connect valves all summer with "0" issues!


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