Quenton's service comments

Quenton Guenther

Well-Known Member
Local time
6:17 PM
Aug 2, 2007
Outer Banks North Carolina
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,

Thanks for the info. I tried to adjust the motor up and down...if the belt was tight it touched the stand-off, if it was clear of the stad-off the belt was too loose. The only way I see it working properly is with at shorter belt. I'll give a shorter betl a whirl and see what happens.

On my bike ther are 3 crankshaft spacers were between the timing gear and the bearing. Is this correct? I might need more spacers to prevent the crank from drifting into the cam gear.

Whizz on...Whizz on.

Boise, ID
I have a question Quenton. I checked the end play by grabbing the flywheel and pushed and pulled and could not detect much play. The belts were off too. Only a couple thousandths give or take. Now my question. Can a WC-1 flywheel be balanced or should I just get a new balanced NE flywheel? And how much $$$ ? I have a pretty nasty vibration at 4500rpms and up. Thanks


BTW I took another ride tonight and I am very happy with the advanced timing results on my engine. The advanced timing did not cause the vibration either. I had the vibration before the modification.
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Hi Jim,
It is possible to have the WC-1 flywheel balanced. I know of several methods, but the most common is to use a bubble balancer used to balance tires. I know the flywheel & alternator were changed on the later model NE5 and the Ambassador, and aren't interchangable with the earlier models. If the flywheel is still available it would sell for over $100.00. I have a lot of parts and will see if I have any extra balanced flywheels in stock and let you know.
If the bearing is tight in the case and the crankshaft is tight in the bearing, the side movement will be kept to a minimum, sadly that isn't a guarantee that it will stay that way, but there is less room to shift because of the WC-1 side cover. I do know that motors with the crankshaft centered run better and last longer. If the crankshaft is stable, all that is needed is a spacer to keep the crankshaft from moving towards the side cover.
Happy to hear the timing advance helps.

Have fun,
Flywheel balancing

The flywheel is a large piece of iron, and can be easily balanced by either drilling to remove weight or adding heavy metal to increase weight. If it was mine I'd drill it since that is free and heavy metal is expensive.
I Have one WZ, two S4's, and Roadmaster WH, 1950 Sportsman, 1950 Pacemaker, and a 1950 Schwinn DX [Panther]. Sure would like to see a picture of the Huffman 90.
My WZ is original [un-restored].

Have fun,
Crankshaft question...

Is the crank from a WC-1 interchangeable with the NE-5 cases? I have various parts in boxes and want to make sure that I don't mix the parts together if they are not... I know many parts are NOT interchangeable, but am unsure of the crankshaft. TIA