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Lifetime Membership
1. Check the front left engine mount as they tend to get torn in the 800, allow twisting of the crankcase, which then causes all kinds of engine problems.
2. If the air suction hose from the bottom back of the crankcase, has been replaced with a red plastic hose, due to the 02 crankcase hose connector not having a bend in it, the red hose can get warm from the engine and kink over causing loss of suction to the fuel pump and fuel starvation.
3. The high beam light connector can cause low rpm engine problems when it burns out. Disconnect it to check.
4. A bad reed in the reed valves causes low rpm engine problems. They need to seal when in the at-rest position. Old ones don't seal and cause loss of compression. Broken ones are even worse requires extremely high rpm to keep the engine running.
5. A leaky VES valve gasket will cause engine problem. Look for tears in both the flat gasket and the rubber diaphragms. While you are at it, check the metal guillotines for impact dents. Replace if has impact dents. If they are not getting stopped at the correct location, they could take out the rings and pistons.
6. Check for choke lever having 1/4" to 3/8" free play before it starts to engage on the carburetor. This problem can appear at any time and cause the engine to rev up slow, not be able to go above 6000 rpm and kick on the DET retard. One mysterious reason can be found at the tiny plastic choke lever box that is attached to the front side of the dash board. The cable feeds into this box through a plastic cap. That plastic cap can become dislodged at any time from just moving the choke cable around or moving the carburetor around. Once that cap comes out of the box, then your choke cable no longer has any free play, which then causes the slow revving and low rpm issues. Another possible reason is the expansion of the casing surrounding the choke cable, when the engine heats up. This may kick the choke just on enough to cause the engine retard to kick in.
7. Look for the suction hoses from the carburetor to the air box to be in place and plugged in at both ends.
8. Look for corrosion inside of the spark plug, rubber plug connector cap. Replace if corrosion is present.
9. Check for idle rpm set too low on top of carburetor.
10. Rear track idler wheel bearings are under extreme stress. All of the rear idler wheel bearings should be replaced with a $10 bearing at 2500 miles or whenever those wheels do not spin freely around your thumb when holding them. All other track idler wheel bearings can be replaced with $3 bearings as required. If you take them off and spin them, you can tell whether there is any grease in the bearing anymore. Replace the bearing if there is no more grease, even though it spins.
11. Front track drive sprocket bearings are also critical. The left side bearing should be regreased with the xerxes fittings every 200 miles. If you have never greased that bearing, it will disintegrate and cause your speedometer to no longer give you speed readings because the key in the middle of the drive shaft axle, has sheared off. Regardless of how often you regreased the left bearing, it will be shot at 2500 miles or sooner. The right side bearings get plenty of lubrication from the chaincase oil and last much longer that the left side.
12. A bad water pump drips coolant out a little hole on the right front of the water pump housing. If you have a serious drip, then it is time to replace the guts of that water pump, which is no easy task. If the engine over heats and you cannot find the cause, the nylon lock nut that holds the water pump impeller onto the pump shaft, may have loosened enough to contact the bottom side of the water pump's top housing. This causes the water pump impeller to seize, engine overheating and a possible broken water pump belt as well.
13. At the large drive sprocket inside of the chaincase, there is a nut and washer that hold the large sprocket on the drive shaft. If this nut is not loctited and torqued as specified, then it could work it's way off the drive shaft, causing the chain case to suddenly seize.
14. A bad temperature sensor thermostat on top of the cylinder cover, will cause the engine to not start. Since a good sensor completes the electrical circuit of the two wires that run into it, the sensor can be checked by unplugging it, and then connecting those two wires in the electrical harness, with a U-shaped wire that has enough insulation stripped to get a connection at the two wires.
15. A thermostat can get so hot that it becomes misaligned and gets hung up in a partly open position. This can cause overheating.
whoisthatguy
Well-known member
Lifetime Membership
1. Check the front left engine mount as they tend to get torn in the 800, allow twisting of the crankcase, which then causes all kinds of engine problems.
2. If the air suction hose from the bottom back of the crankcase, has been replaced with a red plastic hose, due to the 02 crankcase hose connector not having a bend in it, the red hose can get warm from the engine and kink over causing loss of suction to the fuel pump and fuel starvation.
3. The high beam light connector can cause low rpm engine problems when it burns out. Disconnect it to check.
4. A bad reed in the reed valves causes low rpm engine problems. They need to seal when in the at-rest position. Old ones don't seal and cause loss of compression. Broken ones are even worse requires extremely high rpm to keep the engine running.
5. A leaky VES valve gasket will cause engine problem. Look for tears in both the flat gasket and the rubber diaphragms. While you are at it, check the metal guillotines for impact dents. Replace if has impact dents. If they are not getting stopped at the correct location, they could take out the rings and pistons.
6. Check for choke lever having 1/4" to 3/8" free play before it starts to engage on the carburetor. This problem can appear at any time and cause the engine to rev up slow, not be able to go above 6000 rpm and kick on the DET retard. One mysterious reason can be found at the tiny plastic choke lever box that is attached to the front side of the dash board. The cable feeds into this box through a plastic cap. That plastic cap can become dislodged at any time from just moving the choke cable around or moving the carburetor around. Once that cap comes out of the box, then your choke cable no longer has any free play, which then causes the slow revving and low rpm issues. Another possible reason is the expansion of the casing surrounding the choke cable, when the engine heats up. This may kick the choke just on enough to cause the engine retard to kick in.
7. Look for the suction hoses from the carburetor to the air box to be in place and plugged in at both ends.
8. Look for corrosion inside of the spark plug, rubber plug connector cap. Replace if corrosion is present.
9. Check for idle rpm set too low on top of carburetor.
10. Rear track idler wheel bearings are under extreme stress. All of the rear idler wheel bearings should be replaced with a $10 bearing at 2500 miles or whenever those wheels do not spin freely around your thumb when holding them. All other track idler wheel bearings can be replaced with $3 bearings as required. If you take them off and spin them, you can tell whether there is any grease in the bearing anymore. Replace the bearing if there is no more grease, even though it spins.
11. Front track drive sprocket bearings are also critical. The left side bearing should be regreased with the xerxes fittings every 200 miles. If you have never greased that bearing, it will disintegrate and cause your speedometer to no longer give you speed readings because the key in the middle of the drive shaft axle, has sheared off. Regardless of how often you regreased the left bearing, it will be shot at 2500 miles or sooner. The right side bearings get plenty of lubrication from the chaincase oil and last much longer that the left side.
12. A bad water pump drips coolant out a little hole on the right front of the water pump housing. If you have a serious drip, then it is time to replace the guts of that water pump, which is no easy task. If the engine over heats and you cannot find the cause, the nylon lock nut that holds the water pump impeller onto the pump shaft, may have loosened enough to contact the bottom side of the water pump's top housing. This causes the water pump impeller to seize, engine overheating and a possible broken water pump belt as well.
13. At the large drive sprocket inside of the chaincase, there is a nut and washer that hold the large sprocket on the drive shaft. If this nut is not loctited and torqued as specified, then it could work it's way off the drive shaft, causing the chain case to suddenly seize.
14. A bad temperature sensor thermostat on top of the cylinder cover, will cause the engine to not start. Since a good sensor completes the electrical circuit of the two wires that run into it, the sensor can be checked by unplugging it, and then connecting those two wires in the electrical harness, with a U-shaped wire that has enough insulation stripped to get a connection at the two wires.
15. A thermostat can get so hot that it becomes misaligned and gets hung up in a partly open position. This can cause overheating.
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