Shovelhead flywheel part numbers

[Pete Engelman]

Hello everybody
I am buying a set of shovelhead flywheels but can't find the part numbers in my HD parts cataloue and wondered if someone could tell me about these flywheels.
The pinion side flywheel casting number is 23945-41 and the sprocket side flywheel casting number is 23923-70a. I would like to know what years these flywheels are and what year rod sets would work in them.
Also does anyone know what the difference in crank pins is from from 1941 to to early 1981 then from late 81 on
Thanks
Pete::::::::::::::;;;;;;;

[duffeycycles]

Part numbers & casting numbers are not the same

[Pete Engelman]

Ok Thanks for your help
Pete:::::::::::;;;;;;;

[TomL]

Those are part numbers. Right side stayed the same until end of production, Left had changes made over the years. Its from a 1970 or later 1200/74 by those numbers but is it an original matched set? Spocket shaft bearings were changed from caged rollers to tapered timken bearing in 54/55? and I am pretty sure the diameter of sprocket shaft changed prior to 56 when roller set up was discontinued. 1200 rods 7.440" L. Probably the number and/or size of oil holes

[aumick10]

I think from memory there was also a change in shaft tapers where they fit into the flywheels. cannot remember when this happened.

[Rubone]

The pinion side casting number never changed after 41 although machined features did. The shaft taper was the same so the number never changed. The left side has a couple variations in the '70s with the different taper appearing in '72. It is easily identified by the size of the nut holding it on. The 70A number is likely the large taper version. It will fit in any '70s 74CI engine, the 80" flywheels are different.

[kitabel]

Sprocket shaft taper major diameter:
1930-54 1.000" 8½° taper
1955-71 1.250" 8½° taper
1972-81 1.400" 8½° taper (no keyway)
1981-* 1.310" 6° taper

Am I right? Please correct!

[Pete Engelman]

Tom
The seller says the flywheels came out of a 77 FLH so they are likely matching. For the hundred dollar asking price I rolled the dice and bought them.
I'm tossing the idea of turning my 89'' 10.5:1 CR FXS Low Rider that doesn't like today's fuel back down to a stock 74 with an 8:1 CR so I can burn this crappy ethanol fuel we have here today.
Thanks for your help
Pete:::::::::::::;;;;;;;;;

[Pete Engelman]

Tom
The seller says the flywheels came out of a 77 FLH so they are likely matching. For the hundred dollar asking price I rolled the dice and bought them.
I'm tossing the idea of turning my 89'' 10.5:1 CR FXS Low Rider that doesn't like today's fuel back down to a stock 74 with an 8:1 CR so I can burn this crappy ethanol fuel we have here today.
Thanks for your help
Pete:::::::::::::;;;;;;;;;

[Pete Engelman]

Thanks again Robbie

[Pete Engelman]

Thanks aumick

[TomL]

Pete I am doing a 1978 last year 74 inch Shovel as we speak. The wheels and cases are in the machine shop being rebuilt so the numbers are pretty fresh in my memory bank. I think you will ride with a smile on your face with a nice running 1200 I know I will when mine is ready for the highways.

BTW I'm told there were both 74 and 80's in 1979 and I believe that is correct but for just the 1200, 78 was last year.

[Pete Engelman]

Thanks Tom
Pete::::::;;;;;;;;;;

[jim d]

I purchased a new Low Rider in 79. I had my choice of a 74 or a 80 inch motor. That was the change over year. I got a 80 inch. I think that it was $4950 and cost more than the 74 inch model.

[aumick10]

The factory designated 1978 1/2 as the change over date. A 1979 74" probably would have been old stock 1978 model.