Timing Difference Auto Vs Manual

Been meaning to ask this for a while.
The manual states timing for the 390 as 2.18mm BTDC, but the 390 Automatic is stated as 1.61mm BTDC.
Is the difference to ease starting and provide a better tick over ..... ??? Or just a mistake in the manual ?

What year bikes Grouty? Remember the autos are usually built from the previous years left overs!

Says the same in 420 manual I believe but that manual is really a 390 manual!

All mine are 78's.

The 78 390 AMX is 16 deg btdc With the Motoplat ignition. My bike starts well and has heaps of toe.....love that motor.

Found this.........Retarding the timing will make the power band smoother in the mid-range and give more top end over rev. When the spark fires closer to TDC, the pressure rise in the cylinder isn't as great. The emphasis is on gaining more degrees of retard at high rpm. This causes a shift of the heat from the cylinder to the pipe. This can prevent the piston from melting at high rpm, but the biggest benefit is how the heat affects the tuning in the pipe. When the temperature rises, the velocity of the waves in the pipe increases. At high rpm this can cause a closer synchronization between the returning compression wave and the piston speed. This effectively extends the rpm peak [power] of the pipe.

Probably just to make the auto a bit smoother and hit less hard than the manual gearbox bikes. Won't make much difference at low rpm I wouldn't think. It's higher revs where the difference impacts.

The 390cc 71mm stroke is one of the best Husqvarna engines there ever was. The 43 rear wheel hp as stated in the cycle world Husqvarna magazine. For me the rear wheel never stopped spinning. Even a wick of the twistie in 6th gear she would wheelie at will. The 390cr will always be a wild ride to me. I'm sure the auto is no different. I think the autos were a head of there time. The husqvarna bikes were copied but never duplicated.

The more the timing is retarded the more torque there is at the bottom. But the higher rpm is lowered.
It's a trade off.

you have that backwards. retarding timing is what we always preach here to aid in starting and less kickback as well

wheelie at will in 6th with a twist of the wrist? what gearing was this?? 9/60?
sorry but the various 500 husky motors ive run were not able to do this in 6th, which is double overdrive.
my husqvarna guru/sensei always ran a 78 390cr and while it ran sweet, did not compare in overall power to the 10 finner...