Hopefully the information contained will help improve, repair, or modify your Whizzer motor to enhance your riding experience. I will base the following information on actual experiences.
Possible causes of motor vibration at mid to open throttle are usually located in the crankshaft or the flywheel. The earlier WC-1 used an unbalanced flywheel, that if the casting of the flywheel was less than perfect it could shake and get your attention. When the NE motor was released one of the improvements was a balanced flywheel. However the crankshaft generated vibration has many possible causes, including a "twisted" crankshaft. Before I continue on it is important to note the "vintage" Whizzer company felt it important to keep the crankshaft "centered" and used different spacers to keep things in alignment. The vintage company offered 5 different sizes under two different part numbers [#2034 and #2088] with a total of 10 to choose from. The spacers were listed as Crankshaft End Spacer. When the motor was copied by the new company the spacer was "missing in action", and I have seen motors where the crankshaft moved as much as 1/4" from side to side when running. When requesting a fix, I was told to locate a penny in the side cover to prevent the side movement of the crankshaft, if it would have worked it would have been a cheap fix, however it didn't correct the problem. On the majority of the NE motors I have serviced, it is usually the camshaft gear that stops the crankshaft from drifting more, [in many cases you can see deep cut marks on the crankshaft throws] and it would take a lot of pennies to make up the difference. When they made the side cover for the NE motor it was thicker to allow the use of allen screws to attach it to the case, but the crankshaft bearing hole was deeper and would allow the crankshaft to drift more to the right. Do I run my motors this way? Of course not. I always make the needed modifications to hold the crankshaft in center. It usually requires spliting the cases, removing the crankshaft & left bearing, to see if the bearing is loose in the case or is the crankshaft loose in the bearing [99% is loose in the case]. If it is loose in the case I use a sharp punch and "dimple" the aluminum where the bearing normally resides and apply hi tempature Loc-tite, if it is the crankshaft loose in the bearing, I replace the bearing. I next machine a spacer to fit inside the side cover needle bearing to stop the crankshaft from moving to the right. The problem of a "twisted" crankshaft is rare, but does happen. When a needle bearing type crankshaft is assembled, it requires pressing the parts together, and seldom causes problems unless it wasn't in alignment during the process, or someone used an impact wrench to loosen the bolt, or the motor was stopped all of a sudden. The first time I was exposed to a twisted crankshaft was because the owner often used an air impact to tighten or loosen the flywheel bolt, never use any power driven impact wrench on any needle bearing crankshaft. My second encounter was the fault of the automatic clutch going into the destruct mode and locking the drive system. A few more with twisted crankshafts crossed my path, but I wasn't privey to all the data. A twisted crankshaft is easy to spot, if the flywheel "wobbles", you got a problem. But here is the fix, remove crankshaft from the motor [lots of fun], take to local machine shop. The machine shop can easily, with dial indicaters and a good hammer put the crankshaft back in alignment. When I raced Ducatis I often twisted the crankshaft [usually caused by the sudden stop during a crash], and developed a real talent with the hammer as a crankshaft alignmnet tool. Another important note concerns flywheel removal, loosen the flywheel bolt [careful, so far, counterclockwise to loosen, but may change], use a piece of wood and a hammer to tap the front of the flywheel from the side cover side, turn the flywheel slightly and continue to tap the wood against the flywheel, it will "pop" loose. Remove the flywheel bolt and then the flywheel can be removed. If the flywheel is ever removed for any reason, it is a good time to remove the screws holding the alternator coils to the case and coat the screws with Loc-tite, and re-tighten. In order to loosen or tighten the flywheel bolt it is necessary to hold the flywheel in place, just use a peice of wood than can be wedged between the flywheel and the bottom of the case to stop the movement.
My last service comments concerns the front belt. I am often asked "Why does the belt rub the lower belt guard mounting post?". My answer is simple the distance between the clutch and the motor is too short for the stock belt. Either the arm should be a little longer [moving clutch pulley away from motor], or find a shorter belt. On my personal bikes I try to avoid the belt rubbing the motor, because I think it might take a little of my power in the process. I use the AX27 belt[approx. 29" long] because the AX belt worked best on the vintage Whizzers [AX26 was used],so why fix it if it ain't broke. I will address clutch arm modifications in a future article.
Hope this information helps make your motorbike more durable and therefore more enjoyable.
Have fun,
Quenton
Possible causes of motor vibration at mid to open throttle are usually located in the crankshaft or the flywheel. The earlier WC-1 used an unbalanced flywheel, that if the casting of the flywheel was less than perfect it could shake and get your attention. When the NE motor was released one of the improvements was a balanced flywheel. However the crankshaft generated vibration has many possible causes, including a "twisted" crankshaft. Before I continue on it is important to note the "vintage" Whizzer company felt it important to keep the crankshaft "centered" and used different spacers to keep things in alignment. The vintage company offered 5 different sizes under two different part numbers [#2034 and #2088] with a total of 10 to choose from. The spacers were listed as Crankshaft End Spacer. When the motor was copied by the new company the spacer was "missing in action", and I have seen motors where the crankshaft moved as much as 1/4" from side to side when running. When requesting a fix, I was told to locate a penny in the side cover to prevent the side movement of the crankshaft, if it would have worked it would have been a cheap fix, however it didn't correct the problem. On the majority of the NE motors I have serviced, it is usually the camshaft gear that stops the crankshaft from drifting more, [in many cases you can see deep cut marks on the crankshaft throws] and it would take a lot of pennies to make up the difference. When they made the side cover for the NE motor it was thicker to allow the use of allen screws to attach it to the case, but the crankshaft bearing hole was deeper and would allow the crankshaft to drift more to the right. Do I run my motors this way? Of course not. I always make the needed modifications to hold the crankshaft in center. It usually requires spliting the cases, removing the crankshaft & left bearing, to see if the bearing is loose in the case or is the crankshaft loose in the bearing [99% is loose in the case]. If it is loose in the case I use a sharp punch and "dimple" the aluminum where the bearing normally resides and apply hi tempature Loc-tite, if it is the crankshaft loose in the bearing, I replace the bearing. I next machine a spacer to fit inside the side cover needle bearing to stop the crankshaft from moving to the right. The problem of a "twisted" crankshaft is rare, but does happen. When a needle bearing type crankshaft is assembled, it requires pressing the parts together, and seldom causes problems unless it wasn't in alignment during the process, or someone used an impact wrench to loosen the bolt, or the motor was stopped all of a sudden. The first time I was exposed to a twisted crankshaft was because the owner often used an air impact to tighten or loosen the flywheel bolt, never use any power driven impact wrench on any needle bearing crankshaft. My second encounter was the fault of the automatic clutch going into the destruct mode and locking the drive system. A few more with twisted crankshafts crossed my path, but I wasn't privey to all the data. A twisted crankshaft is easy to spot, if the flywheel "wobbles", you got a problem. But here is the fix, remove crankshaft from the motor [lots of fun], take to local machine shop. The machine shop can easily, with dial indicaters and a good hammer put the crankshaft back in alignment. When I raced Ducatis I often twisted the crankshaft [usually caused by the sudden stop during a crash], and developed a real talent with the hammer as a crankshaft alignmnet tool. Another important note concerns flywheel removal, loosen the flywheel bolt [careful, so far, counterclockwise to loosen, but may change], use a piece of wood and a hammer to tap the front of the flywheel from the side cover side, turn the flywheel slightly and continue to tap the wood against the flywheel, it will "pop" loose. Remove the flywheel bolt and then the flywheel can be removed. If the flywheel is ever removed for any reason, it is a good time to remove the screws holding the alternator coils to the case and coat the screws with Loc-tite, and re-tighten. In order to loosen or tighten the flywheel bolt it is necessary to hold the flywheel in place, just use a peice of wood than can be wedged between the flywheel and the bottom of the case to stop the movement.
My last service comments concerns the front belt. I am often asked "Why does the belt rub the lower belt guard mounting post?". My answer is simple the distance between the clutch and the motor is too short for the stock belt. Either the arm should be a little longer [moving clutch pulley away from motor], or find a shorter belt. On my personal bikes I try to avoid the belt rubbing the motor, because I think it might take a little of my power in the process. I use the AX27 belt[approx. 29" long] because the AX belt worked best on the vintage Whizzers [AX26 was used],so why fix it if it ain't broke. I will address clutch arm modifications in a future article.
Hope this information helps make your motorbike more durable and therefore more enjoyable.
Have fun,
Quenton
