Checked all the wires all seem to be in place none touching bare metal. I disconnected the starter and then turned the key I watched and heard the fuse blow. Thinking of replacing the solenoid?
Well you could replace the solenoid, then the starter followed by the alternator, then the regulator followed by the ignition switch then the PTO switch and still be blowing fuses as well as a hole in your wallet.
Back to wiring 101.
Do you have a wiring diagram ?
IF not get one because otherwise you are driving down the street blindfolded.
When you turn the ignition key to the ON position power goes from the fuse through the switch to the fuel solenoid, Oh I forgot that one better change it too it is only about $ 60.
The battery is also connected to the rectifier but you have already randomly replaced the rectifier ( $ 45 ) and the stator ( $ 60 ) and not found the problem with random part replacement.
Now when you go one position further to Start, the battery is connected to the S terminal on the ignition switch from where to goes to the PTO switch then on to the Brake switch and perhaps even a Neutral switch before it ends up at the solenoid.
So somewhere in this chain is a direct short to ground.
A thinking person would disconnect each one of these one at a time till when they turned the switch the fuse did not pop.
Thus they have not wasted a lot of time & money replacing perfectly functions parts.
Now it is your mower and you are footing the bill.
Replace parts at random and hope to get lucky first time , or go through things till you find the culprit, your decision.
No idea who makes Ryobi lawn tractors ( Ryobi do not make anything ) so got no idea which way to send you to find a similar wiring diagram but Ryobi usually put one in their owners manuals and their owners manuals can be downloaded for free if you have your model serial number.
BE very careful with safety switches because most of them have a direct connection to the coil and if you accidentially send 12V to the coil , it is done for and they ain't cheap either.
Hint is most of the switches in the starting circuit are normally open and close when the plunger is depressed.
Now from what I have read you are saying the fuse blows in the ON position before you get to the START position.
SO if that is the case the fuel solenoid on the carb ( if it has one ) or the rectifier &/or stator are prime suspect.
A 20A circuit breaker is about $ 5 so you might like to invest in one of them if it looks like you are going to blow a lot of fuses.
I use an old motorcycle amp gauge with a couple of wires with spades on the end to go into the fuse holder but you can only do this for a short time before the wiring will start to melt.
