Thank you for your purchase of a Maxpower-RPM's 4 stroke engine kit or components. Please take a few minutes to read this bit of information, as it can make your purchase more enjoyable and maybe increase its longevity. Remember this is a race engine; therefore: THERE IS NO EXPRESSED OR IMPLIED WARRANTY OF ANY KIND AS TO THE LIFE OR LONGEVITY OF YOUR ENGINE.

FUEL REQUIREMENTS
All of our kits are normally set up to run best with a mixture of 93 octane pump gas and 110 octane race fuel that equals 100 octane. This is what most modern race bikes require in stock condition. It allows for good starting, tuneability, and a safety cushion against detonation.

If you have requested a higher than normal compression ratio (above 13:1), or are below sea level in elevation, you may need to run straight 110 octane or higher. Remember, detonation kills, when in doubt call us. Likewise if you are in a higher elevation you may need less octane for good throttle response and starting ease. If you hear detonation you need higher octane and richer jetting.

OILS
We get many questions regarding recommended oils, as everyone’s oil is the best and there are many super-magic oils out there. We suggest running petroleum based oil during break in to allow the rings to seat.

Always remember there's no free lunch, full synthetics are great lubricants and are very slippery. But, they can promote clutch slippage in some engines and do not pull heat from parts as well as petroleum based oils.

Example: Have you ever seen the add on TV showing a test engine lowering its oil temp by 20 degrees by switching oils? It's because the synthetic oil is not pulling heat out of the parts as well as the conventional oil that was in it was doing. Synthetics may lube lower end bearings better but petroleum based oil will greatly increase valve spring life because of the heat transferring properties of it.

The best petroleum based oil we've tested is Kendall GT-1. In an air cooled thumper we wouldn't run anything else. Synthetic blends are an option; we've used the Maxima Maxum 4 syn blend with great success. 10w40 weight is great for most conditions with 20w50 only needed under the hottest of conditions in a water-cooled engine.
Most importantly stay away from all oils labeled as "energy conserving".

The moral of the story is this; run high quality oil and change it often. How often? MX'ers should change every two races or practices. GP, desert racers, and cross country racers every race. Because oil is cheap, pistons and cranks aren't.

ASSEMBLY
Assemble your new engine components with the same high quality oil you plan on running.

1. Use a small dull screw driver and your fingers to install circlips after lubricating the wristpin bore, pin, and small end of rod generously. Use of needle nose pliers can distort the circlip and encourage it to come out. The open ends of the circlip must be either at the top or bottom of the wrist pin bore.
2. Don't forget to put a clean rag or towel in the bottom end to prevent dirt or the wrist pin clip from falling into it.
   Use a torque wrench of known quality and torque all fasteners to factory specifications.
3. Lubricate cams and buckets generously.
4. It's not only important to time the cams correctly but to torque cam holders to proper spec in the correct order. We've seen properly torqued cam holders, torqued in the wrong order, bind up and gall into the head, ruining expensive camshafts and cylinder heads.
5. Before installing your exhaust pipe, blow it out with compressed air.
6. Look inside your carb and boot to ensure cleanliness. This is a great time to remove the air box boot and reseal it to the air box.
7. You're not going to start that new engine with the same dirty air filter are you? Clean, dry and properly re-oil before you fire it up. Dirt can destroy your engine in less than 10 minutes.
   

STARTING/BREAKING IN YOUR NEW ENGINE
Before starting your new engine for the first time, step back, and breathe in and out a few times. I know you're excited, but there's more to do yet.

Is it full of new coolant? Did you tip it side to side a few times to encourage air bubbles to come out? Did you double check the oil level, oil lines, coolant lines, drain and fill plugs for tightness. Also did you make sure the carb is fully in the manifold and throttle cable is routed properly and has free play? Is the spark plug tight and coil wire on? Give her the complete once over.

Most four strokes are notoriously hard to start with a freshly oiled air filter. Many people over oil their filters which makes it even worse. HERE'S A TIP THAT MAY SAVE YOU MUCH GRIEF AND SWEAT. On machines equipped with a throttle position sensor on the side of the carb, unplug the TPS and turn the idle speed adjuster up1/2 a turn. Kick the kicker all the way from top to bottom with a man sized kick. "Bunny Kicks" won't start a modified thumper much less one with a freshly oiled air filter and rings that aren't seated. Once it starts let it run at a fast idle with a fan blowing in the radiators until the radiators are as warm as what you would wash dishes in, stop the engine and let it cool off. Repeat 3 or 4 times. Do not BRAAPP, BRAAPP, the throttle to hear how your new creation sounds. The top end, (cams, wrist pin etc...) is the last place to get oil when freshly started, plus this is extraordinarily hard on the piston. Once warm you can plug the TPS back in.

Every time I see the guy at the track parked next to me start his engine up cold and rev the berries out of it I see a rebuild coming my way. Don't be this guy.

Next, resist the temptation to immediately go blasting down the street W.F.O. to let your neighbors now that you got your engine back. While combustion is warming and expanding your piston to size, the rush of cold air is keeping your cylinder from doing the same. Then BANG, cold seizure. Yes, thumpers can cold seize too. Be nice to your engine is the best way to describe break in procedure. Avoid high rpms right away, but don't over lug it either. Up and down through the rev range is the best way to seat the rings. Change the oil and filter soon after the first tank of fuel. Now you can let your neighbors know how well you like it!

PISTON AND RING LIFE
A common question is: When do I need to replace my piston and rings? The easy answer is 15 hours depending on rider and conditions.

What conditions you say? Well it's like this: your young hotshot "A" rider bouncing off the rev-limiter will need to replace the piston at around 10 hrs or less. While your average vet rider who uses more of the torque curve and fewer rpm might be able to go 20 hours or more. A 250f will need a set of piston and rings before a 450f would. This is due to the rpm range the engine is used in. A person who races in power robbing Southwick sand will need them before the supercross rider on hard-pack would.

Our Apticote 2000 cylinder coating doesn't wear the rings out, dirt does. Always replace them as a set. After all the piston went up and down as many times as the rings did.

We highly recommend an hour meter. We like the Dr. D hour meter, it's cheap, horribly easy to install, small and easy to hide. Contact us if you’d like to purchase one.

Keep an eye on how much time your piston and rings have on them as the days of selling you’re XR600 with the original piston and rings in 5 years are long gone.

WARRANTY DISCLAIMER:

• AS STATED ON OUR WEBSITE, CATALOGS AND INVOICES WE OFFER NO EXPRESSED OR IMPLIED WARRANTY ON THE LIFE OF YOUR ENGINE. REMEMBER THIS IS A RACE BIKE.
• MOTOCROSS AND PERFORMANCE ATV ENGINES ARE MUCH MORE STRESSEED THAN YOUR F-150. TAKE CARE OF YOUR ENGINE, YOU OWN IT.
• EVERY CYLINDER WE REPLATE GOES THROUGH A 30 POINT CHECK LIST;EVERY ENGINE GOES THROUGH A 73 POINT CHECK LIST. CYLINDERS AND ENGINES DO NOT LEAVE HERE WITH DEFECTS.
• EVEN WITH PERFECT MAINTENANCE AND REASONABLE USE, AT SOME POINT EVERY ENGINE FAILS. AFTER THE ENGINE IS REPAIRED IT IS ONLY A MATTER OF TIME BEFORE IT FAILS AGAIN.
• WHEN A ENGINE EVENTUALLY FAILS OR BEFORE WE WILL GIVE YOU UNLIMITED FREE ADVICE, AND CHARGE YOU FAIRLY TO REPAIR IT.
• WE LOVE ATV'S AND MOTORCYCLES, BUT WE CAN NOT WORK FOR FREE. PLEASE RESPECT THIS AND YOUR EQUIPMENT.