Did not read the correct answer but in my opinion (and I have balanced ship turbines and huge ship wheels), that was Harley excuse for not being able to balance it 100% without two balancers.

It takes two since Harley's share the same crank pin. The fire opposed, but if you study it, one always arrives at the top a little ahead of the other.

A TCb has two balance cams for that reason.

I have ask this before but is there a difference in the balance of a Rubber mounted cruiser now and the solid mounted Softail M8

 

As long as all the rotation circular, it's pretty easy to balance. When you add in a piston and connecting rod it gets more complicated. This place was set up by a guy smarter than anyone here, me included.


https://tonyfoale.com/



If you go here you can look at some tools used to balance single cylinder motors. There is a free program that show what the imbalance is for a single cylinder motor under downloads. Here is a pic.




The round plot shows the imbalance of a single cylinder motor.. Look at the polar (round) plot. It shows that the forces of imbalance are not a nice circled vector of force that can be canceled by a counter rotating balancer.

The reason for the 2 balancers on a TC and M8 softail is that they help to cancel the fact that one balancer only is offset from the crank. The twin balancers essentially place the counter balance dead center of the crank..

 

Is there two for a M8? I thought only one.?

 

Baggers 1 , Softails 2 ,. I think .

 

Softail M8 appears to be same internal configuration on only one balance cam. That was what I was saying in 11 above and what Max with his elaborate balance details is showing that each cylinder would need one to be close. And when it comes to piston engines, with rods and pistons and maybe a little difference in compression, you can only get so close.

 

Pretty sure the baggers have 1 and the Softails 2 man.

 

If you're talking counterbalancers, yes the Touring models have one and the Softail models have two.

 

Egzachary.

 

The first attachment is a M8 motor single balance cam in 2017 and up Harley line. Single cam is gear driven from the left side of the motor.

Second attachment 2 cams from older TCb motor. Cams are chain driven from a sprocket on crank behind oil pump that you see on the crank in third attachment from the right side of the motor.

Please post your 2 balance cam Softail M8 2017 or later M8 motor you are referring to.

 

The parts stream micro phish shows one for the touring engine and two for the Softails.

https://partstream.arinet.com/Mobile...AZJzCpfs1.html

https://partstream.arinet.com/Mobile...kjmmnmGA1.html