Pony - Check your wiring - a 1 meg pot should shut off anything. Check it with an Ohmmeter to be sure it's really 1 meg. Also, if a load resistor is used (read below) check its value. These can vary a lot in value.
ALSO an added note for Silimtao on his RG and changing your volume pot value - read on... Also, Seymour Duncan probabaly made the humbucker in your RG. Check out their website first as they post the Ibanez specs. You might end up buying the same pickup you already have.
Pot value does not change signal "output" at full volume, but resistance value of the volume pot can change the "characteristics" of a pickup, at any volume. This is because it loads the entire circuit (even with pot at full CW, [U]ground is at full resistance[/U]). The pot value will alter the pickup's "attack" toward it's peak frequency. Changing pot values changes the "amplitude" of the pickup's peak frequency across the tonal spectrum. This is often called "sparkle" or "quack" with single coils or like Pony calls "bark" on his humbi. Modern high output humbi's are not effected by pot value as much as the single coils are.
General rule - higher value pot - faster to peak.
A 1 meg pot loads the circuit more and allows the pickup to jump to the peak frequency faster. Smaller value pots spread it out or "tame" it. Put a 1 meg on a strat and it sounds like Sh*t. Usually - start with the recommended pot values by the pickup manufacturer.
Yamaha RG's are mostly 1 Humbi, 2 single configurations. Increasing the volume pot value will alter the single coil pickups sound significantly. I doubt you will like it.
NOTE - This goes for the tone pots as well since they are part of the circuit. Don't throw 500k tone pots in a strat with a 250k volume. Keep the values the same.
More cool stuff:
You can drop a resistor between the input and output of lugs on the volume pot to make the pickup think there is a smaller value pot. This will tame the pickup more. Experiment with 50k, 100k and 150k 1/2 watt resistors for humbuckers guitars loaded with 500K pots.
Check out Guitar Nuts website for wiring.
If you want more attack (like I do), drop in a 1 meg with a resistor. The pickup now "sees" a different load but somethign greater than the stock 500K. Try some 100k up to 300K resistors. OR better yet.............
VERY COOL - Instead of a resistor, drop in a "trim pot" with a value of around 250K or even higher. A trim pot is a very small pot that is turned with a screw driver (some have a little finger knob). Wire this as a variable resistor (only using the input and output). Install as above. Now you can dial in the amount resistance you want without the hassle of changing resisitor values. I have even converted tone controls to do this by wiring them in place of the trim pot. Then you can change the pickup characteristics while you're playing.
You might want to install a 0.001µF (microfarad) capacitor in parallel with the resistor or trim pot as a treble bleed circuit to retain the highs when you roll off the volume. All my humbi loaded guitars have this.
Here on some tips on pots.
1. Don't buy cheap pots. Personally, I see nothing at Stewmac that resembles a quality volume pot and the majority of guitars on the market are loaded with crap electronics. Check with your local high-end electronics store (Radio Shack DOES NOT qualify). Pick out a good, sealed, plastic composite or wire wound, audio (logrithmic) taper pot. Have them check the values with an Ohmmeter right there. Make sure it is zero at full CW and very close to the rated value at full CCW. These high quality types will often have a rectangular case with small lugs a metal tab for ground. Overheating pots can ruin them. If you do not know the correct way to solder, have someone else install them. These will last a long time, are very smooth and very, very quite. They will never need cleaning. Take you old one in with you to be sure you get the correct shaft/collar length.
I once thought a "Sweeping Arpeggio" was an Italian janitor.
