Rudeness is not appreciated. I did my best to adjust the timing with the info I had. I used the 3* +/- 1* from Mr Joe Reeves. It wouldn't idle at all with the timing any more retarded than that.
I don't know what the carbs are from but they have fixed main jets, adjustable idle jets, and the same bore as the originals. Spark has not been tested over a 3/8 gap but I will. Both carbs have fuel and the floats were set according to the seloc manual. I've been using a multi-year / horsepower manual I bought online not the exact factory manual.
The last couple of Months there has been a Tsunami of owners trying to adjust 'Idle TIming' and fiddling with the sync between spark and throttle in an Attempt to set the Idle speed. And it gets a little tiring/frustrating
Most 3rd Party Service Manuals are not even good reading material for the Outhouse, and the paper is too slippery to use as Wipes.
Since there are often changes from year to year on engines, a model specific service manual is really the only way to go as it will explain what every adjust screw/threaded rod is for.
If the carbs are the same size(venturi bore, as well as throttle bore, it doesn't mean the fuel flow calibration will be correct before or after a Jet swap. If the carbs came from a 50 HP or a 60 Hp, the calibration may have been different because of differences in Exhaust Tuning(again, what applies to 2 stroke engines is different than to car/truck engines), Off Idle fuel delivery could be different, etc etc etc.
It was mentioned above about a Displacement change, that happened in 76 when the 41 cubic in. 50 hp became a 44 cubis in. 55 hp. In 1980 the 55 hp was upgraded to 60 hp, same displacement(internal changes though)