First Laps

Next is a quick snapshot of what you should do to shake down the kart and orient yourself. Be very aware of your surroundings. Keep an eye on the drivers around you as you come up to speed. Get comfortable and get a sense of what the kart is doing. Here are just a couple of basic tuning tips.

If the kart does not want to turn, you have what is called understeer, or a push. This means the front end needs more grip. To make a quick change, widen the front track by moving the front wheels further apart. Move the front track out 1/4” (5 mm) at a time until this condition improves.

If the back of the kart wants to get sideways in the turn, you have what is called oversteer or a loose condition. This means the front-end has too much grip and needs to be made narrower. Move the front track in 1/4” (6 mm) at a time until this condition improves.

If the kart is wandering as you go down the straightaway, the front may be out of alignment. It could have “toe out,” where the wheels are pointing away from each other or “toe in,” where the wheels are pointing toward each other. This is corrected by adjusting the tie rods. It is recommended that you put on the proper alignment gauges and check for the correct toe setting. A correct toe setting is usually between zero toe to a 1/4” (4 mm) total toe out. Check with your local kart shop for details on what alignment tools are available. The Odenthal Exact-Toe™ is a good system (shown below), along with the Sniper™ laser system.

What to Look For

When you come in from your first session, here is a list of some basic things you need to check. These basic checks should become habit for you after every on-track session. Have your charts ready so you can quickly write down the information.

The first thing to check is the tire pressure. It is CRITICAL to get the pressure readings immediately in order to get accurate HOT tire pressures.

Compare these tire pressure readings to the COLD pressure settings when you went out. Each tire should have increased from two to three psi. Check the tires for any cuts or marks that may indicate a problem with the tire.

Now it’s important to have a quick look at all the components of your kart.

Make sure all the brackets are still tight. Make sure that there are not any nuts or bolts loosening up. Check to see if you have any fuel leaks. Look for fuel under the seat and on the back of the kart. Make sure that you check all lines for cuts, rubbing or chafing. It is recommended that all fuel lines be secured with a small tye wrap to keep them from backing off their nipple.

Next, pull the spark plug and check for color. It should be a light brown, almost coffee color, in the middle porcelain area, and black on the outer metal ring around the porcelain. If the color is drastically different, consider a jetting change.

When the engine has cooled, slowly remove the oil drain plug, usually located at the front of the engine. Let the oil flow through your fingers and feel for any particles or metal shavings in the oil. Try to let the oil flow into a measuring cup to make sure the level is down to make sure the system is not leaking. Extreme caution should be taken when removing the oil drain plug to avoid injury from hot oil. Put the plug back in carefully and DO NOT over tighten.

Finally, have a look at the chain tension. A new chain will stretch as it breaks in. If there is more than 3/8” (9.5 mm) of play, adjust the chain. As you move the engine forward, make sure that the clutch is clear of the seat.

Be sure to write down any notes as you run through the post session review. This information will be very valuable as you begin to fine-tune your kart.

Maintenance – Keeping it Clean

One of the more important things you can do for your kart is to keep it clean. I live by the saying “A clean kart is a happy kart and a happy kart is a fast kart.” The idea being that anything mechanical operates better when properly maintained and cleaned. This eliminates possible problems and helps you discover loose bolts or damaged parts before they become an issue and lose you a race.

Start by blowing off all the dirt and dust you can. Be careful when using compressed air. Always wear safety glasses when using an air hose. Next, take a rag and lightly coat it with Torco™ penetrating oil PL50. This will help cut through the grease and grime on your kart and help to keep rust from forming on any bare metal surfaces. I usually start with the front of the kart, which is usually the cleanest, and work my way back. The chain area is the last spot to clean.

It is a good idea to remove the wheels and clean the hubs and rims. Use this opportunity to check the studs, rims, bolts and tires for damage. Don’t be afraid to pull off the hubs and give them a quick cleaning. Make sure you take width measurements before you pull them off. Most hub problems come from grit and grease getting in between the hub and the axle, either causing them to slip or be difficult to adjust.

Make sure you give each surface a quick shot of brake cleaner before you put them back on. Your hubs should move easily when loosened and be solidly in place when tight. Put the wheels back on and tighten the stud bolts firmly.

Another area to keep clean is the rear axle. With a chain and chain lube, this area can be a real mess. The grease flies everywhere and then attracts grit.

Start with a clean rag and remove as much as possible. Use PL50 to loosen and remove the stubborn grease on the bearings, axle and rear gear. Using PL50 ensures that you lubricate at the same time as you clean. Clean the entire rear-end, including the bumper, the frame, bearings and the cassettes, by putting some PL50 on a rag and wiping the surface. This makes the next cleaning even easier.

Properly working brakes are important and you should take the time to maintain them and check for any problem areas. Start with a dry rag and remove as much dust and grime as possible. Clean in and around the rotor hub and the caliper.

Use a good quality brake cleaner. Take the nozzle hose and spray into the brake caliper. This should force any brake dust or track grit out. Don’t be afraid to use the cleaner, as it dries with no residue. Try not to soak the pad itself.

Another area to keep clean is the engine. I start at the top of the engine using contact cleaner and compressed air. For those areas with heavy grease, a toothbrush along with contact cleaner and compressed air works great. Don’t go crazy with the contact cleaner and make sure to keep it away from all painted surfaces. If you have run off course and picked up a lot of dirt, don’t forget to remove the tank bolt and clean underneath the fuel tank. The grit in between the floor pan and the fuel tank can act like sandpaper and wear on both the plastic tank bottom and the aluminum surface of the floor pan.

After a race day you should pull the engine for a more thorough cleaning. Remove the engine and place it on your bench. Before you begin, place a clean piece of shop towel or cloth into the exhaust and the intake opening to make sure nothing gets into the engine while you are cleaning it. Wipe off everything and make sure you clean all the electronic parts. Wipe off the chassis where the engine mount sits and also wipe off the side of the seat, which usually gets covered in grime. Clean the engine mount thoroughly, including the brackets that go underneath. You want a nice, clean contact between the engine mount and the chassis to ensure the engine does not move.

Another part that gets overlooked is the steering column support bracket.

This is a friction fit area and can collect a lot of grit. Remove the bracket bolt and slip the bracket up the steering shaft. Wipe off the column and put it back in place with a little PL50 for good measure. Make sure to wait a few minutes before reinstalling so all of the PL50 can run through.

The best to clean the bodywork is using a soapy/warm water solution, similar to what you would use to wash your car. After removing and cleaning the bodywork with WD40, use the soapy solution and soft wash mitt to remove all the stubborn stains and rubber marks. Do one piece at a time and immediately rinse with clean water from a hose. Using a towel immediately after to dry the bodywork will help to replenish any lost moisture back into the plastic and help it to keep its shine.

Now that we have our kart onto the track, in the next installment from Memo Gidley’s Secrets of Speed for Four-Cycle Kart Racing we take a look proper driving techniques.

Read more of this series at GORACINGmagazine.com

Memo Gidley is an avid California kart racer, instructor, and former Target Chip Ganassi Racing Champ Car driver.  This article is from his book, “Memo Gidley’s Secrets of Speed for Four-Cycle Kart Racing”.  You can purchase the book, as well as learn more about Memo at his website: MGSpeedSecrets.com.

From Basket Case to Bitchin
By Mike Kojima @ MotoIQ.com

Lately the MotoIQ staff has been Karting a lot to get our speed fix for few bucks.  Running MotoIQ is an expensive endeavor and we have had to mostly give up racing cars for now to keep MotoIQ growing and strong. Looking for cheap used Kart parts on Craigslist one day, we happened upon an ad for what seemed like a lost cause.

 We thought that the kart was pretty rough and in poor condition but noticed that the engine looked pretty new.  Turning the crank by hand showed it to have good compression.  Basically we first bought the kart thinking it could be a source of spare parts for Christa’s race program but now its just too nice.  It is way too big for Christa to drive though!

There was an early 2000’s vintage CRG Heron kart for sale for the very tempting price of $300, super cheap for such a machine.  The ad stated that it didn’t run but for $300, the picture looked like it was complete, straight and equipped with an IAME HPV engine of some sort and a Mychron III electronic dash.  Well we figured, it was worth a look since Italian CRG karts have an excellent reputation, the kart was new enough so its technology would not be too out of date and the parts on the kart were worth way more than $300. Used HPV engines usually go for around $1000 if they are in decent shape for instance.  Worst case we could use the engine as a spare for Christa.

The main reason why we bought the Kart was for its Parilla IAME HPV-4 engine (no it does not stand for Human Papillomavirus Vaccine ).  The engine looked to be in pretty good shape compared to the rest of the Kart.  An HPV engine usually goes for around $1800-2000 dollars new and around $1000 used.  The differences between the HPV-4 engine and the HPV-1 used in Christa’s kart is a pipe tuned for more top end power and a larger WB3A Walbro carb.  The HPV-1 puts out around 8 hp and the HPV-4 puts out around 18 hp in stock form.

Checking the Kart out we found it to be very weathered but in OK shape, the frame was straight, by spinning the crank by hand, the engine had decent compression, but the brakes didn’t work.  The engine was an HPV-4, the most powerful variant of the venerable piston port two stroke IAME Parilla HPV engine range that pumps out 18-20 hp at around 16,000 rpm. The HPV race classes use a spec clutch and a spec pipe which we like because clutch and pipe tuning in other classes like the Yamaha KT100 classes are a major hassle and expense. The cool thing is the engine looked to be in good shape; it looked newer than the rest of the kart. The frame looked like it had been repainted in some parts with house paint. The steering wheel was oxidizing apart as was the old plastic bodywork, every part on the kart was rusted, especially the axle and fasteners but everything was there.  If anything we could use the kart for spare parts.

The other reason we bought the Kart was this Mychron electronic dash which was worth about the price of the Kart!

The owner told us he had bought the kart used a few years ago from a racer and had wanted to use it but could not figure out how to start it and had lost interest in it.  He pushed it out into the patio/back yard to rot and wanted to get rid of it as it was taking up too much room around his house.

The Walbro WB3A carburetor is a diaphragm pumper type that uses crankcase pressure pulses to pump the fuel.  It was hopelessly gummed up with old fuel and oil residue.  This was the reason why the engine would not run for the previous owner.  A good cleaning and an $18 rebuild kit make the engine a strong runner.  We added a foam filter from Empire Karts inside the airbox.

The expansion chamber used on the HPV-4 engine is a lot shorter than the one used on the restricted for kids, HPV-1 engine.  The shorted length means that the reflected wave is timed better for high rpm use.  Embee Performance coated our chamber with their satin black thermo barrier coating.  HPV racing classes do not allow the switching of chambers and all racers must use a spec chamber.  This eliminates a lot of expense due to pipe tuning like the Yamaha KT100 classes must have if you want to be competitive.  The flexible slip joints and spring mounts keep the pipe from cracking due to fierce two stroke vibrations.

Getting the kart home we decided to see if it could be made to run.  Spinning the engine with the starter proved that we had spark, but looking in the oxidized and crusty fuel tank confirmed that the fuel system was hopelessly gummed up.  Opening the master cylinder showed that the brake fluid had also turned into a gummy mess.  We did a little research and found that Acceleration Kart Racing in Las Vegas seemed to have the best selection and prices on CRG OEM parts so we gave them a call and found them to be quite friendly and helpful.

The HPV engine class rules state you must use this spec Horstman clutch.  The KT100 rules allow clutch tuning and this is a big part of being competitive.  The HPV rules don’t allow this and thus saves a lot of time and expense.  We broke the stock chain and ruined the sprockets so we replaced these parts with an Empire Karts sprocket and a more compact and lighter Top Kart sprocket carrier.  A gold DID roller chain is long lasting and low friction.

A few emails and some photo swapping identified our parts and a package with fuel line, a new fuel tank, caliper, master cylinder and carb rebuild parts arrived two days later.  We cleaned out, honed and rebuilt our brake system which was really quite easy and carefully cleaned and rebuilt our carb, changing our spark plug for good measure.  We bled the brake system with fresh Motul 660, freed the gummy axle bearings by soaking them with tri-flow, and filled the tank with some premix VP MS98 fuel blended with Motul Kart synthetic mixed at 30:1 and gave the starter a whirl.

The brake is a CRG twin piston with a floating vented iron rotor.  We rebuilt the caliper.  All of the silver parts on the Kart are billet magnesium and they were badly corroded and frozen to the bolts and bearings.  Magnesium is highly reactive and corrodes really easily.  We bead blasted them all and sent them to Embee for clear powder coating.  The rusted hardware was replaced with stainless allen bolts with trick nut retaining clips from Baller Bolts.  We straightened and polished the bent and rusty axle and cleaned, repacked and honed out the bearings.  Embee blasted and powder coated the frame which had been painted with latex house paint!

To our surprise, the HPV started instantly. Blipping the throttle, the engine was sharp and responsive.  We put air in the tires and blasted down the street, the thing was fast!  Apparently this was a fresh almost new engine and it didn’t run simply because it had sat and the fuel system gummed up with stale pre mix residue, a best case scenario.  The brakes also worked well now.

The master cylinder was full of gummy old brake fluid residue and white corrosion.  We cleaned and honed out the bore and rebuilt the old and dry seals.  The brakes now work really well. The adjustment rod was rusted solid and had to be replaced as well.