There are many other stock motors on the market. Some of them are simply Green Machine IIs with racing brushes installed. As a beginner you are better off with the standard Green Machine II, which has brushes that produce a bit less power but are far easier on the commutator and allow the motor to last much longer.
Trinity has just introduced the Midnight stock motor to succeed the GM II. I have yet to see a Midnight on the track but judging by past history it should be a step forward.
You will get longer life from a mild modified motor. You may want to practice with a modified and save the stock motor for races. You'll need a wider range of pinion gears to run different motors (see next topic.)
If you only buy one pinion, buy one that's two teeth smaller than the recommended one. As a beginning driver you will be carrying less speed through the turns than a more experienced driver, so you will need to run a smaller pinion than the more experienced drivers do.
I like Team Losi pinions because they use a 5-40 set screw. The drawback of the 4-40 set screws used in other US brands is that they are more prone to stripping. It can be hard to remove a pinion whose set screw has stripped!
A convenient feature to look for when choosing a pinion gear is a visible indication of the number of teeth. There are few things so tedious as counting the teeth on a gear.
All the pinion gears I've been talking about are 48 pitch gears, which match the spur gears supplied in competition-level Losi and Associated kits. 64 pitch gears are too easily damaged in off-road use, while 32 pitch gears give away too much efficiency. 48 pitch giears are the right compromise.
Since different brands of hobby-quality CA glue seem about the same, I buy based on the quality of the packaging. The glue is pretty useless if it has leaked out, or if the package has become glued shut. My favorite CA glue package is Pacer's, which has a double cap. It travels well.
Resist the temptation to buy the large economy size; you won't be using glue that quickly. A 1 ounce bottle will last you a long time, and even a 1/2 ounce bottle will mount quite a few tires.
Be sure to read and follow the label directions when using CA glues. CA will bond skin to skin, so be careful; you *really* don't want to get any into your eyes. Wear safety glasses. Some individuals display allergic reactions to CA glues. Avoid getting it on your skin (disposable latex gloves ensure this) and avoid breathing the vapors.
The solvents in paints for R/C car bodies attack the polycarbonate material, giving the paint a better grip. They also attack your nervous system. Be sure to read and follow the label directions when using these paints. Wear glasses and a respirator and do your painting outside if you possibly can.
Buy the smallest tube of RTV adhesive you can find; it goes stale in the tube. When the adhesive loses that ultra-sticky consistency coming from the tube, it is time for a new tube.
Be sure to read and follow the label directions when using RTV adhesives. The solvents are really bad for you, so keep the stuff off your hands and use RTV in well-ventilated places only.
Motor spray is also good for spraying out wheel bearings as they get gritty; re-oil with one drop of light oil after spraying.
The components of motor spray that are bad for you are absorbed readily through the skin; always wear safety glasses and rubber gloves when using motor spray.
Trinity/Revtech drops work, are not horribly expensive, and are widely available. Recent lab tests reported in R/C Car Action show that the more expensive Race Prep and Extreme drops produce more power than the Trinity drops.
You can live without this wrench for awhile, but once you've had one you'll never go back.
Again, you can make do with a plain Allen wrench. But you will become very familiar with the motor screws as you adjust gear mesh each time the motor goes on after cleaning. You'll be happier with a quality wrench.
Your first motor for modified racing should be mild, not wild. You want something that's faster than stock, but still easy to drive. Most beginners in modified go slower in modified than in stock, but if you pick the right motor you can go faster right away.
Modified motors are rated by turns and strands. A 14-turn triple has three strands wrapped fourteen times around each pole of the armature.
Other things being equal a motor with fewer turns draws more current, has more no-load RPMs, and produces more power. (This explains why a stock motor is specified to have at least, not at most, 27 turns.) A motor with fewer strands has more "snap" -- it accelerates more quickly from low speeds. A motor with the same number of turns and more strands has more power at the top end.
If you buy a 14-turn triple from Reedy, it won't necessarily perform the same as a 14-turn triple from Peak Performance or Trinity. The variables include the quality of laminations in the armature stack, the strength of the magnets, the wire size and winding pattern used, the diameter of the commutator, and the choice of brushes and springs. But if you stick to one line of motors, you can predict the relative performance of two motors by knowing their winds.
As a beginner in modified you want a motor with a lot of turns and a lot of strands. Especially a lot of strands -- at least four for a buggy, three for a truck. Otherwise you will spend all your time spinning out while you try to develop the sensitive throttle control needed with a big motor.
A mild modified motor that I like a lot is the Reedy Mr. K 17-turn quad. This was the only motor I used in my first year of modified racing. These days I usually run a 12-turn triple in my buggy, but I keep a Mr. K handy for running on very tight tracks and tracks with bad traction. I've worn out a couple of Mr. Ks through hours of use. The Mr. K is well suited to 1400 SCR batteries; a 16-turn triple should perform similarly on 1700 SCRCs.
Of all the makers of off-road racing motors, Reedy offers the widest choice of winds. This is an advantage because if you want to go a little hotter or a little milder, the motor you want is nearly always available. A case can also be made for Trinity motors. Trinity offers a huge variety of winds, but many of them are only available as armature upgrades. Trinity points out that if you want to try a lot of winds it is cheaper to buy armatures than whole motors. Reedy sells only whole motors; his theory is that when the armature is worn out, the magnets have lost enough of their strength that you need a whole new motor.
If your kit involves any screws that thread into metal parts, you'll need to use a thread lock compound to keep the screws from loosening. The standard thread lock compound is blue Loctite 242.
It pays to do a careful job of the gluing. You want the tire/wheel assembly to run true and you want the job to be strong. The fussy-sounding procedures below are designed to meet these goals.
First, examine the mounting surfaces of the tires and trim away any excess rubber with sharp scissors. This permits the tires to sit down straight and true on the wheels. Next, clean the mounting surfaces of the tires and the wheels with rubbing alcohol. This removes any mold release agents from these surfaces and allows the glue to work its best. Then mount the tires on the wheels, and get them true. One way to get them true is to hold a mounted tire between your hands, press in slightly, and spin the tire back and forth with a rubbing motion. Do this a couple of times, shift the tire 1/4 turn, and repeat four or five times.
Use a thin CA glue (e.g. thin Pacer Zap, Hot Stuff, blue Goldberg Jet). A narrow tip applicator makes the job easier. Place the mounted tire on a table with the outside of the wheel facing up. Pull the tire very slightly away from the wheel so you can apply a drop of glue between the tire and wheel. Work your way around the wheel until the tire is entirely glued, then flip over and glue the other side in the same way.
Now your wheels and tires are ready for use. At some point this set of tires will wear out and you will want to replace it. You can remove the tires from the wheels by boiling the tire/wheel assembly for a minute or so. The easiest and safest procedure is to cut the tread surface from the worn out tire before boiling; this prevents scalding hot water from collecting inside the tire, where it might squirt out and hurt you. After boiling, you should be able to pull the sides of the tire from the wheel without leaving any rubber behind. You will leave some glue behind; clean this off completely with a small file before mounting the next set of tires.
This is not a soldering tutorial, but here are a few basic tips:
Heat-shrink tubing can be applied over solder joints for insulation and finished appearance. Use heat-shrink in preference to electrical tape - it is more permanent. To shrink the tubing, hold a hot soldering iron close below it or a match farther below it.
You will see advertisements for nifty temperature-controlled soldering irons. Unlike regular soldering irons, you can leave a temperature-controlled iron hot all the time while you are racing, so it is ready the moment you need it. (Leaving a regular iron on without using it for long periods of time will greatly shorten its life.) The drawback of the temperature-controlled soldering iron is cost -- roughly $100. And soldering irons don't last forever, especially not when you are carting them back and forth to the race track. You will be better off spending the money on something else -- like high-quality connectors that reduce the need for using a soldering iron.