Master Mechanic Pete Shows Us How to Rebuild a Tired Engine
If you’re going to ride, you’re also going to wrench now and then. Most of the time that means nothing more than changing the oil, cleaning an air filter, or simple adjustments. Every so often though your mechanical buddy will need a major rebuild, the most common of which is replacing piston rings. On a two stroke this was no problem; pop the cylinder off, hone the bore, install new rings, and get back to riding, often times in the same afternoon. Today’s high-performance four-stroke motors are an entirely different animal however but there’s no reason to be afraid of the job. We’ll show you how to rebuild a modern four stroke engine and we’ll give you a few tips to make the job easier.
Piston rings are designed to fit snugly against the cylinder bore, and to capture the full power of the combustion stroke by preventing superheated combustion gasses from escaping past the piston. Any leaks past the rings reduce compression, which means power loss. We recently changed rings and cylinders on our Can-Am Renegade 800 but changing the rings on any modern four stroke will follow the same procedures. Here is how to get your engine back in top shape.
1: WASH YOUR MACHINE. It makes it so much easier to work on your engine without dirt constantly trying to fall into any open orifice.
2: OWN AN AIR GUN, SAFETY GLASSES, and GLOVES. Safety glasses and gloves are a must, especially when working with springs, rings, or grit that can fly in practically any direction.
Compressed air is a very useful tool. A good air gun nozzle is super handy for blowing away grit you missed with the power washer. Be sure to blow out spark plug holes before taking out plugs.
3: TOOL TIME. You’ll need a decent tool kit. No need to buy everything, but a set with some good sockets, (preferably 6 point), a couple different sized ratchets, Allen wrenches, torx bits, and box end wrenches will be needed.
An electric impact is a HUGE bonus and one of the best investments you’ll ever make.
4: REMOVE THE BODYWORK. Start clearing a path to the cylinder and head. On our Can-Am Renegade this meant removing the seat, the front nose piece, and the side panels. We also removed the airbox.
5: COMPRESSION TEST. A compression test can tell you what’s happening with the engine before you ever open it up. Test both cylinders and record your findings.
COMPRESSION TEST TIPS. Install the tester into the spark plug hole. Turn the key on, and crank over the motor with the throttle held WIDE OPEN until the dial shows maximum pressure and holds it. You must hold the throttle fully open for maximum air flow. Record your finding; this is the DRY TEST. Now pour a small amount of oil (a small spoonful) into the cylinder and repeat the test, again with the throttle fully open. This is the WET test. If the WET TEST maximum number is significantly higher than the DRY TEST number it means exhaust gasses are leaking past the rings and the rings need replacing.
If the WET TEST number is about the same as the DRY TEST, it means the valves are leaking and they need adjustment or replacement. Now you know where the problems likely are.
6: DRAIN THE OIL and RADIATOR COOLANT. We drained the coolant by removing the radiator hose where it entered near the bottom of the engine.
7: TAKE GOOD PHOTOS OF BOTH SIDE OF THE ENGINE. A couple good detail shots of each side can really help out during reassembly.
8: REMOVE EXHAUST. You’ll need to remove the exhaust to remove the cylinders. On our Renegade, that meant pulling the rear storage box for better access to a couple nuts that hold the muffler on. To remove stiff exhaust springs, tightly clamp one end of the spring with a VISE grip and use it to remove the springs. Don’t forget your safety glasses and gloves for this step!
9: REMOVE ELECTRICAL CONNECTIONS, FUEL LINES, and EFI THROTTLE BODY. Remove EFI throttle body fuel lines by releasing the spring loaded connectors.
Some connecters require you pry them open, and some require you to compress them enough they release internally. On our Renegade you must press the black portion tightly to release the pressure. Once you remove the fuel line you will spill a little fuel. Cap the open line so no dirt enters. (We taped ours up with electrical tape.) Remove the EFI Throttle body from the bottom of air box. You can leave it attached to the throttle cable however.
Remove any electrical connections in the work area carefully. Look for the little release tab on the connectors, and always pull while holding the connectors. Never try to separate connections by pulling on the wires.
10: REMOVE COOLANT LINES IN WORK AREA. For crimped on connections (one-use-wonders) you’ll need to cut the steel band and replace with new hose clamps during reassembly.
11: REMOVE HEAD COVERS.
12: REMOVE CAM CHAINS. We did this by loosening the cam chain adjuster, and by removing the center bolt on the cam gear.
When removing head and cylinders DO NOT let cam chains fall into bottom of motor. A small wire or zip tie around cam chain can help prevent this.
13: REMOVE THE HEAD.
14: REMOVE FRONT, UPPER MOTOR MOUNT.
15: REMOVE CYLINDER BOLTS and CYLINDER. If cylinder is stuck to base gasket do not pry between cylinder and mating base surfaces. You don’t want to scar the mating surfaces and create a possible leak. GENTLY tap the cylinder with a rubber mallet, a piece of wood, or the wooden/rubber end of a hammer handle while lifting cylinder. Now remove all remaining gasket material from all mating surfaces on engine cases, cylinder, and head.
16: INSPECT PISTON & RINGS. When checking piston, check for deep grooves & wear on skirt and sides of piston. Look for wear on rings, or a ring that is stuck in groove on piston. Also check top of piston to see if anything has contacted it.
When done, cover open holes into motor with a CLEAN rag. You don’t need anything extra falling into motor.
17: INSPECT THE CYLINDERS. Ordinarily a cylinder should still display a dull crosshatch from the last honing. Ring areas may be worn completely smooth however. Worn or damaged cylinders will often show a gouge or groove from the ring, or you can feel and see a slight groove where the ring reached maximum height near the top of the stroke. If you can feel or see any grooves / wear areas your cylinder has problems and exhaust gas is flowing past the rings.
18: BOTTOM END BEARING CHECK. When the cylinders are removed you can give your lower end rod bearings and crank main bearings a quick check by grabbing the connecting rod and giving it a tug or two. You should not be able to feel any up and down movement, and only a little side to side movement from the rod and main bearings.
TIP: A sure sign of bad crank or rod bearings is excessive noise from the engine when it’s running.
If you hear lots of clatter from the lower end of the motor, chances are you’ve got a lower end bearing problem
19: CHECK RING GAP and INSTALL RINGS. This step used to be mandatory but rarely do we need to adjust the gap on new rings anymore. To check for proper ring gap, slip a ring into the new cylinder, then using the piston as a tool, slide the ring up until it is square in the cylinder bore. Now you can measure the end gap (The gap between the ends of each ring) and compare it to proper specs as called for in the Clymer manual. After checking gap, gently install new rings onto the pistons while being careful not to bend or break them. A bent or broken ring means that you have to buy a whole new set.
20: INSTALL NEW PARTS. Once you’ve determined what parts you need (rings, cylinders, pistons, or all of the above) it’s time to start putting everything back together. Don’t forget the new gaskets. We usually put the gaskets on just as they come from the factory, but some riders will coat them with a thin film of oil first.
During installation of new parts be sure to leave a clean rag covering the hole into bottom of engine. You don’t need anything falling down into the motor. This is especially true when installing the circlips that hold the wrist pins. Lose your grip on a circlip and they can shoot anywhere and they’re hard to find.
TIP: Remember to keep cam chain from falling into bottom of engine
21: INSTALL THE PISTON INTO CYLINDER. Coat the inside of the cylinder and the rings with a thin coating of engine oil. Now insert the piston into the cylinder by compressing the rings with either your fingers or a ring compression tool. GENLTY slide the piston and rings into cylinder. DO NOT force anything. If you feel anything catch, stop until you can correct the problem. You don’t want to break a ring in the assembly process. When cylinder is seated on base begin tightening cylinder bolts in a cross pattern. By “cross pattern” we mean by tightening one bolt part way, then a bolt on opposite side of cylinder part way, repeating the process by continually jumping across cylinder to a bolt on opposite side.
This applies even clamping force to the cylinder. Snug all bolts down evenly. Now, using your torque wrench and the correct torque specs in the Clymers manual, tighten bolts to correct torque spec, again using a cross pattern. Now slip cam chain sliders (the large black plastic pieces) and tensioner into correct position while fishing cam chain up through cylinder
22: INSTALL HEAD. Install the new head gasket and thread the cam chain up through the cylinder and into the head. Now install head bolts. Again snug down evenly using a cross pattern to tighten bolts. Next grab your torque wrench again and torque bolts to correct spec using cross pattern method for tightening. Set cam chain onto cam gear, and slide gear onto cam shaft in correct position. When seated correctly, tighten cam bolt.
TIP: When reinstalling head on the rear cylinder of the Rotax engine it will be impossible to install long head bolts under fame rail after head is in place on cylinder.
Slide the long head bolts into their holes before setting head on cylinder to save yourself the aggravation later.
23: CHECK TIMING. Open the two crank positioning holes on the lower right side of the engine. The big hole at the center is for turning the crank, and the second hole above it is for marking position. Don’t lose the O-rings to either cover! Install the cam chain and with the spark plug holes open roll over motor BY HAND to check timing. DO NOT use the electric starter for this step. If you have the timing off the piston may hit open valves. When checking by hand you’ll feel this if you’ve got a problem. The electric starter, however, has enough torque that it will likely bend the valve. Be sure the engine goes through a complete revolution with zero problems.
TIP… If you don’t have an Allen wrench large enough to fit the crank bolt head you can easily make an ordinary bolt do the trick.
Find a bolt that fits the head and clamp it with a Vise Grip. This will work as your makeshift Allen wrench, and it will easily have enough torque to turn over the motor with the spark plugs removed.
Look into the crank position observation hole, and with a large Allen wrench slowly rotate the crank until you can read either T1 or T2 on the fingers going by. T1 means cylinder one for the forward cylinder, while T2 is for the second or rear cylinder. Stop on T1 in the EXACT CENTER of the observation hole. When you are stopped in the correct position, the two lines on the side of the cam gear should be parallel to the top of the head gasket mating surface.
24: VALVE ADJUSTMENT. Now is the perfect time to check the valves. Try to move the valve adjusters with your fingers. You should feel a slight amount of play. Take the feeler gauge and measure the gap between the valve top and the adjuster base. On our Renegade the INTAKE valves should have .
004” (4 thousandths) gap, while the EXHAUST valves should be set for .006” (6 thousandths) gap. Slide the feeler gauge in and out. It should go in with just a slight bit of resistance, and have a slight bit of drag when coming out if used properly, almost like you were pulling it between two of your fingers as you lightly squeezed it.
If the proper feeler gauge won’t go in, or there is extra play, your valves are out of spec! Loosen the 10mm jam nut on the top of the adjuster, turn the adjuster as needed, and retighten the jamb nut. Firmly tighten the jamb nut (a little more than snug) but don’t go overboard like it was an axle nut. Recheck valve for correct feel with feeler gauge.
Repeat this process for each adjuster. Be sure to get correct gap for each adjuster. .004” gap (4 thousandths) for INTAKE VALVES, while the EXHAUST valves should be .006” (6 thousandths) gap. Since the Renegade has two heads, with 4 valves each, you should have 8 adjusters total.
After FRONT (T1) cylinder is done, turn crank to position T2 for REAR cylinder.
Repeat adjustment process.
25: REINSTALL VALVE & TIMING COVERS. With all valves now properly adjusted, check valve cover gaskets, and reinstall covers.
26: REINSTALL HOSES, LINES, & ELECTRICAL. Reattach all connectors, fuel lines, hoses, etc. Make sure no dirt enters fuel lines, and use new hose clamps where coolant lines attach to head. Route wires neatly using plenty of zip ties.
27: REINSTALL MOTOR MOUNTS & EXHAUST. Reinstall motor mounts, exhaust, and all shields.
28: FLUIDS & FILTERS. Install new air and oil filter, and refill all fluids. We recommend the OEM fully synthetic oil, or Mobil 1 fully synthetic.
29: REINSTALL BODYWORK
30: BREAK IN. When everything is reassembled you should be ready to fire the engine. As always, let it warm up sufficiently before heading out for a ride. Break in your new motor as you would a new machine as called for in your manual.
That’s usually 30 minutes of normal riding without pulling heavy loads, major hill climbs, or anything that requires extended full throttle operation or lugging the motor. Basically, vary the RPMs and take a nice, 30 minute casual trail ride that wouldn’t scare your grandmother. Your motor will thank you for it.
Regular maintenance is part of the fun of riding. Changing the rings on a high-performance engine sounds more complicated than it actually is, and regardless of the model, the required tools and techniques will be very similar. Usually the hardest task is getting all the other parts, plastic, and hoses out of the way! Take your time, get the correct specs for your machine from a manual, and dive in. Your engine will be running like new in no time!
How do you rebuild an ATV? The goal is to rebuild it before that happens. Keep an hour meter on your ATV. Dr.D ([951] 808-1114) sells a great one.
Under hard use, you should think about replacing the piston in a sport ATV after 50 hours. Beyond that, you should also have a magnetic drain plug.
How do I know if my engine has been rebuilt? Check the cylinder bores. You may want to use a micrometer to determine the bore diameter, very worn cylinders may be too far gone to allow a successful rebuild. If you know the engine hasn’t been rebuilt previously, you can get a good idea of the wear to the cylinder walls by looking at the cylinder ridge.
Is rebuilding an engine a good job? Rebuilding an engine is a big job, but planning smartly for a successful rebuild project can help eliminate the possibility of costly mistakes, saving you time, energy, and frustration.
How much does an ATV carb overhaul cost? If you can get away with just buying a kit from Amazon or cycle-parts.com, it will be a bit cheaper. An ATV carb overhaul should include the disassembly, cleaning, clearing of all passages, reaming jets, tuning accelerator pump timing and replacement of needed parts.
How much does an ATV carb overhaul cost? Typically, it will cost between $75-200.
Table of Contents
What Are the Benefits of Having an Engine Rebuilt Instead of Replaced? Rebuilding a damaged engine may be a more economical option than full replacement. In an engine rebuild bearings, gaskets, and seals are replaced.
So to answer your question, if an engine rebuild is done well, the engine absolutely can last many tens of thousands of miles. And if you really plan to keep the car for 75,000 or 100,000 miles, you should consider finding a good car that you like, and then having the engine rebuilt yourself.
It’s not difficult. But it is very expensive. Making and selling cars has tight profit margins. It can be a lot cheaper to buy an engine off the shelf than to design one from scratch.
The benefit of replacing the engine with a new or rebuilt engine is that the car can be expected to run for many more years.
Replacing the engine is almost always less expensive than buying a new car. Benefits and disadvantages come with both new and rebuilt engines.
“A rebuilt engine can be as good as the OEM one,” Snyder said. “Sometimes a rebuilt engine can maintain the original engine warranty.” A salvage title could have many underlying problems like flood damage or a serious accident history, while a car with a rebuilt engine has just one concern: the motor.
What’s the average cost to rebuild an ATV Engine? It costs averagely around $500 – $700 to rebuild an ATV engine. But some ATV repair shops asks you to buy the new parts needed or give them an upfront fee for the parts need to be replaced and charge an hourly rate for the rebuilding work.
So to answer your question, if an engine rebuild is done well, the engine absolutely can last many tens of thousands of miles.
And if you really plan to keep the car for 75,000 or 100,000 miles, you should consider finding a good car that you like, and then having the engine rebuilt yourself.
If your car engine is damaged and you place a used engine or a rebuilt engine in your car, it can give a new life to your car but not more value. Because these engines have usage history and they will not run for a long time as your previous motor and cut the value in the price of your car or vehicle.
2-3 weeks is super fast time. 1-3 months is more typical.
“A rebuilt engine can be as good as the OEM one,” Snyder said. “Sometimes a rebuilt engine can maintain the original engine warranty.” A salvage title could have many underlying problems like flood damage or a serious accident history, while a car with a rebuilt engine has just one concern: the motor.
“A rebuilt engine can be as good as the OEM one,” Snyder said.
“Sometimes a rebuilt engine can maintain the original engine warranty.” A salvage title could have many underlying problems like flood damage or a serious accident history, while a car with a rebuilt engine has just one concern: the motor.
Engine rebuild The advantage to having your engine rebuilt is the lower cost. However, since not all the worn parts are replaced, you can’t be sure how long they it will last. You might get a warranty with an engine rebuild, but it typically isn’t for very long.
Rebuilding engines is not HARD work, it is fine work with much measuring, machining, mating, matching and such. Special tools are needed to clean the block and heads, mill their mating surfaces flat, bore the cylinders and line bore the main bearing and cam bearing mounts.
What Does an Engine Rebuild Cost? If the crankshaft is scored, the cylinder head can’t be rebuilt, the pistons need to be replaced, or the engine block is badly damaged, the engine rebuild cost could be thousands of dollars higher yet.
Sometimes, an engine rebuild just isn’t worth it, like if your engine seized.
What Are the Benefits of Having an Engine Rebuilt Instead of Replaced? Rebuilding a damaged engine may be a more economical option than full replacement. In an engine rebuild bearings, gaskets, and seals are replaced.
ATV drownings happen quite often, and the consequences of these drownings are sometimes very deplorable - from electronic failure to engine water hammer. But all this can be avoided if all measures to restore the ATV after drowning are carried out competently and as soon as possible.
The fate of a drowned person can befall everyone, from a beginner to a professional, and absolutely no one is immune from emergencies. Sometimes a harmless 3x3 puddle can turn out to be up to one and a half meters deep, or the ice on the reservoir turns out to be not the thickness that we expected, situations are different.
That's why it's always better to go for a ride, fishing or hunting with a partner, it is he who will help you retrieve the vehicle that has gone under water and tow it home. And, of course, it’s not worth taking risks in vain, if there is an opportunity to go around a water obstacle, believe me, it’s better to do it.
So let's get straight to the point.
After the ATV is out of the water, the first step is to disconnect the battery, thereby de-energizing the electrical circuit and protecting expensive electronics from short circuits.
Do not attempt to start the ATV under any circumstances, as this could lead to irreversible damage and costly repairs.
ATV will have to be towed to the garage and the necessary set of measures carried out as soon as possible:
1. Unscrew the air filter cover, drain the water, wipe the housing dry from the inside, dry the filter, soak it with oil and put it back;
2.
Thoroughly flush the carburetor with clean gasoline or flushing fluids and blow through the channels;
3. Completely drain the gasoline from the gas tank and rinse with clean gasoline, change the gasoline filter;
4. Unscrew the exhaust pipe, drain the water, clean and dry if necessary;
5. Disconnect all electrical wiring connectors and spill them with silicone grease, it is also necessary to do with the dashboard;
6. Drain the water from the variator, be sure to unscrew the variator cover, you may have to rinse and clean the plates, and also dry the belt;
7. Check the presence of water in the engine. We take out the oil dipstick and evaluate the condition of the oil: when water enters the engine, the oil reacts with water, and the so-called “emulsion” is formed, on the oil dipstick it looks something like this:
8. If an emulsion is detected in the engine, immediately drain the oil and flush the engine, for this you need to stock up on 10 liters of the most common motor mineral water M 8.
We unscrew, dry or change the candle, as well as the oil filter;
9. Fill in M 8 oil, connect the battery and turn the starter a couple of times without a spark plug;
10. Next, install the spark plugs and start the engine for 2-3 minutes, then turn off the ATV and drain the oil. The cycle sometimes has to be repeated up to 6-7 times, until the traces of oil completely disappear. As a rule, the first drained oil contains the largest amount of emulsion and looks something like this:
11. As the flush cycles go through, the oil will turn to its normal color, after that, replace the M 8 oil with the one you use constantly, it would be good to temporarily upgrade the oil class to please a flooded engine;
12. Change the oil in the front and rear gearboxes, you may have to change the oil in the gearboxes twice. After the first change, give a small load on the gearboxes, hanging the back and front of the ATV in turn, then change the oil again;
13.
Syringe the ATV's suspension and all parts that are equipped with grease fittings;
14. Dry the seat, thoroughly inspect all components of the ATV and eliminate any traces of moisture found.
As you can see, the set of measures is quite large, but you can deal with the problem yourself without resorting to the services of service centers. We wish you not to despair if the situation with the drowning of the ATV happened to you, most importantly, do not panic and strictly follow our recommendations. And also consider whether it is worth tempting fate once again or whether it is better to find a safe detour. Good luck on the road, stay with us.
And finally, a video on how to do it is not worth it. )))
When buying an ATV, every motorist expects to get a reliable and high-quality vehicle that can give a lot of positive emotions and impressions during operation.
However, buying an ATV is only half the battle. In order for it to really give a lot of pleasant impressions, it still needs to be serviced regularly, including engine repairs. Why?
Under the influence of external factors or due to untimely maintenance, some motor components may fail. It is far from always possible to drive an ATV to a service center for engine repair, and therefore it will be useful to learn how to put an iron horse on its feet on its own, without resorting to the help of professionals.
Do-it-yourself repair of this bulky motorcycle is not only possible, but also extremely exciting. That is why many ATV owners prefer to resort to outside help only in the most critical situations. You can independently carry out not only minor repairs, such as replacing tires, bearings, oil seals or brake hoses, but even repairing a vehicle engine.
Since ATV riding involves extreme conditions and off-road conditions, you should always have tools with you to quickly repair your motorbike in the event of a breakdown.
Luckily, everything you need can easily fit into a small box.
To repair an ATV engine and other components, you need the following tools:
Armed with the tools listed above, you'll be ready to fix almost any motorcycle problem. ATVs 125cc and over are no exception. Consider, as an example, the symptoms and troubleshooting procedure for a Stealth 500 ATV engine.0003
Haisan stealth 500 ATV engine will need to be removed and disassembled before repair. At the initial stage, you need to drain all the oil while the engine is on the frame. Then you need to disconnect all functional components from the ATV engine, such as the fuel system, electrical equipment and muffler. When you disconnect the attached technical equipment from the engine, you can unscrew the fasteners with which the motor is attached to the frame and remove it. On some Stealth motorcycle models, for example, on the 700, only two people can remove the engine.
Check for serviceability, and in case of failure, replace the following ATV engine components:
After all the ATV engine repair work is completed, it remains only to reassemble the engine and return it to its original position. Pay special attention to ensure that all nuts are well fastened.
If you are afraid of making a mistake in the process of installing or assembling an ATV engine, then take a picture of each step of the work before dismantling it.
Owners of Chinese ATVs with a 139 fma engine most often encounter the following types of breakdowns:
If you do not have experience in the repair and maintenance of ATVs, then it is best to drive the vehicle to a service center, where highly qualified specialists will help you diagnose a breakdown and return the vehicle to working condition. It is recommended not to forget about the regular maintenance of the motorbike in order to avoid its breakdowns at the most inopportune moment.
