From ATVs to Karting to Everything In Between - Engine Builder Magazine

From ATVs to Karting to Everything In Between

While small engines are in many types of equipment and toys, there isn’t anything small about their potential for engine builders to make a profit.

From karts to all-terrain vehicles (ATVs) to motorcycles, for many engine builders looking to add profit margins to their business or to get into a specialized area of the industry, small engines offer plenty of opportunities. Sure, you can make more money on bigger automotive engines, but you may not get to build as many, and you certainly can’t turn them out in large numbers with a one-man operation. That isn’t the case, however, in the small engine business.

Putting The ‘Go’ in Karts

Karting has long been the starting point for many (if not most) of today’s professional drivers, and karting continues to grow even when other forms of racing do not. Finding a local club to offer your services to is only an Internet search and visit to your local kart track away. Many kart tracks of all shapes and sizes are dotted across the country, and some tracks are part of the same road racing courses and short track facilities where the big cars run such. From there you have your choice of oval racing, sprint racing or road racing – depending on what you’re closest to and most comfortable with building.

It is estimated that in the U.S. there are between 100,000-125,000 active kart racers in various classes and sanctioning bodies, including local karting clubs. Typical karts cost between $3,000 – $8,000, and many have highly modified racing engines capable of propelling a racer up to speeds well over 100 mph.

The World Karting Association (WKA) and International Karting Federation (IKF) are the biggest karting organizations and both sanction regional and national races throughout the U.S. Many kart racers compete on a national level, however most kart races are sanctioned by the local kart track and loosely follow one of the national sanctioning bodies’ rules. A racer can choose to run on dirt, paved ovals, street courses, full-size road courses or scaled down sprint track road courses. So kart racing can be very rewarding for the whole family.

Karting, like other powersports, has two popular engine styles: 4-cycle and 2-stroke engines. Two-stroke engines put out big power considering their small, lightweight package. And the good part for you is that professional engine builders build most of these engines. In some cases racers build their own engines but most competitive racers buy professionally built engines, or have them “blueprinted.” Kart racers who do build their own engines often bring them to kart engine builders to fix whatever they may have done wrong.

Briggs & Stratton engines can be found in many of the local and national classes from kids to adults. There are thousands of these engines in various forms throughout the country. But racers tend to take their engines to the engine builder who is winning the most, so it’s a good idea to get involved with some local racers and learn what you need to do to help them win. A good engine on a slow kart is not going to help your reputation as a wining engine builder.

A kart engine builder, as in most other forms of racing, needs to sell his reputation as well as his engines. If you are associated with winners then you are perceived as a winner and others will be more willing to seek your services

Of the Briggs engines in karting today, the old flathead engine is still the most popular. And there’s still a good supply of both engines and parts even though the manufacturer has discontinued it. The engine that many clubs and organizations are hoping will take the flathead’s place is the Briggs OHV Animal engine, but this has been a slow process due to so many flathead engines still in use.

One karting expert says that about eight out of ten karters are racing with the Briggs engine in various classes (sprint and oval). The 5hp Briggs & Stratton engine can be compared to the small block Chevy, as it’s the most popular 4-cycle engine and probably the most raced engine in the history of karting.

For engine builders who build small block automotive engines, building a Briggs will be a relatively easy transition. They are very similar in the way you work on them and tools that you need, say experts. And you can buy anything you need for the 5hp Briggs engine in the aftermarket (e.g., cams, heads, etc).

Some engine builders say they like the variety of building both 4-cycle and 2-cycle engines. But because of the number of classes and engines involved, many engine builders become specialists in one or two classes of racing (e.g., TAG, Shifter kart or Yamaha 2-stroke engines).

One expert recommends that 2-stroke engine builders pressure test these engines often, almost like checking your blood pressure. If a 2-stroke engine is not running right and doing strange things, the first thing you should do is a pressure test it and rule out any air leaks.

As with most race engines, following the basics and paying attention to details that are the key – get it straight and square above all else. For 2-stroke builders, tweaking the port timing is how you put your own spin on a build. So if you get an engine that was ported and built by someone else, there’s not much you can do to make it your own design.

This is why some kart engine builders say they prefer to work with new cylinder heads and new engines because it’s a blank canvas for you to paint how you want. The reality is, however, that you’ll likely have to work on a variety of engines to start out.

A kart engine – whether it’s 2-stroke or 4-stroke – is a very simple engine, but there is a lot of time involved on small details and in looking for little gains. Experts say you may not make a lot of money on the initial engine build compared to other engines, instead you have to build a good engine and then keep the racer coming back for a rebuild.

Rebuild prices vary quite a bit from engine builder to engine builder, so the important factor is to charge enough for your labor and parts to make it worth your time and effort.

For Water and Dirt

The personal watercraft (PWC) and all-terrain vehicle (ATV) markets fit somewhere in the middle of the overall powersport segment, which also includes motorcycles and snowmobiles as well as small utility vehicles and outboard marine applications. The powersport market is quite large with many nuances associated with each market segment that an ambitious engine builder would need to learn in order to find success.

While the powersports industry overall is healthy, experts we spoke with say the PWC market has peaked in recent years. These experts point out that one of the reasons the PWC industry has been struggling is that most manufacturers switched from 2-stroke engines to more reliable 4-stroke engines. The PWC side of the market is much smaller and definitely more flat than the ATV market, says one expert.

Engine builders and suppliers say they have been heavily impacted by the change from 2-stroke to 4-stroke engines in the PWC market. Some lakes and recreational areas have banned PWCs in recent years because of the noise and smoke these machines used to emit and many still associate this trait with these types of watercraft.

Experts hope the newer 4-stroke engines, which burn cleaner and run quieter will help to  bring the PWC market back. However, 4-stroke engines simply don’t require as many rebuilds as the 2-stroke engines did.

With the onslaught of 4-stroke engines in the market, with it will bring about a different type of market and different failures. Experts say you won’t see the catastrophic failures of the past, such as a rod through the block, or melted pistons. Often, when 2-stroke engines fail it’s related to a fuel or carburetion problem.

If you’re thinking about servicing the ATV market, it may be a good choice as it is bigger than the PWC market and other powersport segments. Some specialty shops are specializing in building big bore engines for ATV applications. One company that builds stroker motors and big bores caters to the higher end of the market; people who are putting $3,000-$4,000 into the engine. The most popular ATV engines are around 700cc, but ATV racing engines are limited to 450cc. So there is a distinct difference between the sport models and race models.

There are a a lot of DIYers and ATV specialists doing headwork on 4-stroke engines, but experts say many of them aren’t equipped to build engines with valve and seat type work, which could open the door for you to get some of this work. More ATV enthusiasts are clamoring for performance builds so there’s definitely an opportunity for builders to do this type of work.

With the manufacturers heavily pursuing 4-stroke engine designs for their new watercraft and ATVs, engine builders may find themselves in a unique position to benefit from the changing tide. Many automotive engine builders already have the necessary equipment to service these engines, which typically have multi-valve OHC cylinder heads.

A single cylinder OHC engine should be relatively easy to setup for service and require very little investment in new tooling. Experts agree that engine builders who can work on these cylinder heads, providing valve jobs as well as porting and honing services will have a big advantage in the market when it comes to working on these engines.

The move to 4-stroke engines  in ATVs and motocross can be an advantage for traditional automotive engine builders because most of these shops are equipped with tooling for late model engines, which typically have multi-valve OHC cylinder heads. Therefore, a single-cylinder OHC engine shouldn’t be a challenge with regard to tooling or machining issues. The ability to offer multi-angle valve jobs as well as porting and honing will create more opportunities for those shops who travel down this path.

One of the aspects that may present more of a challenge for automotive engine builders is rebuilding the crankshaft. These cranks are press-fit and require special jigs to get them to align properly. It can be tricky to set them up at first, but experienced engine builders say it just takes a little practice to get them right.

Motocross This Path

Motocross is back, and it’s hot right now. Tracks and events are full of riders, and new manufacturers are dotting the motocross landscape. The new 4-strokes are gaining popularity in the sport, a sport that is more and more mainstream thanks to the X Games and Supercross.

In the motocross market there are some opportunities for shops to do specialty work, similar to other powersports segments, such as installing big bore kits as well as custom cylinder head and port work.

Many of these customers want performance engines, say experts. It’s amazing what some of these guys will spend on their engines to be competitive or to show off something unique to their friends.

It’s not uncommon for an ATV or motocross engine to sell for as much as $10,000-$15,000.

One ATV and motocross engine specialist says that the majority of the work his shop does is performance related – boring, sleeving, plating and performance valve jobs. There’s a lot of performance work going on in the smaller engines, too, and there are many aftermarket parts available for these applications.

Customers in this market are typically very knowledgeable. Even recreational riders are passionate about performance.

Experts say that owners of older machines are clamoring for performance engine work because they’re trying to keep up with the newest 4-stroke technology.

A look at some of the valvetrain components of the latest fire-breathing 4-stroke 450s reveals dual overhead-cams; five titanium valves in one DOHC configuration. And one manufacturer actuates four valves with its patented Unicam configuration, which is designed to reduced overall engine height, keeping the center of gravity as low as possible.

Most motocross racers service their  bikes in the winter, so there is little down time for a busy shop. Additionally, performance work on these engines seems to be a niche within a niche. Doing big bore conversions and custom porting offer some profitable opportunities for engine builders in this market.

Experts say there aren’t enough performance rebuilders servicing this market. ATVs and dirt bikes are very popular, so there’s a fairly large market for them.

There really is something for everyone in the small engine powersport market. The market size is enormous when you start to think of all the dirt bikes, karts, ATVs, PWCs and snowmobiles there are. These toys are within reach of most budgets, and so is the engine work.Though they look like kids toys, karting is not just for kids. There all classes for everyone from junior to the over-35 masters crowd. These engines range from 50 cc cadets to all out 125 cc (and some 250 cc) shifter karts capable of speeds well over 100 mph.Motocross racing is extremely popular not only at the professional level but also at the local level as well. The sport is popular among the nation
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