Diagnostic puzzle 1997 sea-doo speedster

[TradeMark 1564]

I just recently brought a 1997 Sea Doo speedster with twin 787's and was wondering why whoever owned it last would've by-passed the MPEM to start the left engine?....If I start the right then the left will start no problem but upon taking a closer inspection I saw that they cut the left start button wire at the first junction and ran two new wires. I followed the new wires and I saw they go to the Electric box where they are directly hooked up to the cellenoid......Odd but it works, only problem is I can't start the left engine without starting the right first.....Very Weird....well anyway I'm new to the forum and thanks for any replies.....Also what is the best type of battery to use as the previous owner had a car battery in there....Boat works so I'm happy, just puzzled.

 

[sunbaby69]

marine battery or gel battery. Probably had issue with wiring and instead of fixing they bypassed OEM starting system

 

[seadooya]

probably, if you replace the solenoid, that motor will work then, with hooking back up original wires to start button.