When drilling, even on a drill press, lock the work down. Some times you can get by with just clamping it in a vise and skooting the vise arond so it's lined up and drill. Most of the time though, if the work can move, you are likely to snap a drill. Same for the tap. The tip above about using the drill press to start the tap is good advise. Drill the hole and then tap it. move the setup for the next hole and drill and then tap.

Short cuts will get you every time.

Drilling is a drill and peck operation. Going through an aluminum motor mount, It would be a minimum of four steps. Drill down about 1 1/2 times the diameter of the drill and then lift it to clear the swarf. anothe drop of fluid woudl be good here. 1 1/2 times again and lift and clear again.

A lot was mentioned about tap fluid, It serves two purposes. Lubercation was the first, but it is also a coolant. It keeps the drill from heating up and siezing in the hole. Same for Taps.

There are two basic kinds of taps and several variations of each. The common taps we get from Dubro and the hardware strore are hand taps. The will have either 2, 3, or 4 straight flutes and come in a starter, long taper, a plug, short taper, and a bottom tap. The hand taps cut the threads and the chipps pile up in the flutes. If you turn in to much with out backing up to break the chips you can jam up the tap. A good rule it two to three turns when first starting the hole and then back up 1/2 turn. The I recomend 1 tunn in and a 1/2 to break the chip. If you feel the tap starting to get really hard to turn, take it all the way back out and clean the flutes, blow the chips out of the hole and go again.

The other style of tap is a sprial point tap which is designed to push the chips through the hole, rather than pull them into the flutes. As you can guess, you need a through drilled hole, they won't work in a blind hole. With the sprial point taps, you don't back them up, other than to remove them from the hole when you are finished. These taps also have only two flutes and are quite a bit stronger than a hand tap.

My recomendations for motormouns is to drill and tap. Use the exact size hole at the motor lugs. IE a 52 magnum four stroke, or an O.S. 52 both use a #6 screw. The 70 and 92 four strokes use a #8 screw. If you then use a socket head cap screw with a proper split ring lock washer, you will never have trouble with loose screws, providing that you tighten them down properly to start. I use thes on the composit mount, like the Dave Brown also. Withe that style mount, the front holes will usually show a little thread just before the bottom of the lug. This is not a problem as you will have at least 10 to 15 turns of screw in the hole which is more than enough.

One place where I use a nut on the motor mountig screws is if I need to add weight up front. I cut a strip of 1/8" lead sheeting about 1/2 to 5/8" wide, and make it long enough to span the mount lugs and loop under the engine. I form it in the shape of a U with ears and then clearance drill. I use extra long front engine screws, long enough to clear the bottom of the lug and then a couple sheets of the lead, a flat washer and a nut. You will add about 1 1/2 oz of very effective nose weight like this. Just make sure to use thread lock on the nuts as the lead will deform something awful.

Don