In previous posts I had been trying to determine what is causing my prop ventilation ring and plastic hub insert to melt at higher RPMs, I still do not have a cause or fix for this but I am thinking it has something to do with the LU, since I cant find anything wrong with the rest of the engine. My existing lower unit was modified by one of the previous owners, some paperwork (dated April 2002) that came with the boat shows that the gears were swapped out, but the paperwork does not indicate what gears/ gear ratio was installed it also appears that some exhaust porting was done on the underside of the midsection four holes were drilled under there on each side and 3 of four on each side have been plugged with screw as well as a couple small sections were cut out as seen in the photo. I have tried calling the place where the work was done but I am afraid that they have gone out of business. I'm not sure if replacing the LU with a stock one will fix my issue but I would like to know what the gear ratio should be from the factory and how to determine what the gear ration is on the LU now. I contacted the person I purchased the boat from and he indicated that this issue never happened to him while he owned it, but who knows how truthful he is being however according to the paperwork these mods were done in April of 2002, so I doubt this was a chronic issue. Any help is appreciated! Thanks in advance!
1995 Ranger 492 VS
Engine is a 1995 Mercury 225 EFI
The SN for the Engine is: OG274631