Hey guys I'm having issues with my 50hp merc. I have rebuilt the carbs and plugs trigger lower unit oil water pump etc. I don't have a manual for it and need to know how to do a link n sync on it. Or possibly an answer to why it only runs at about 1/3 throttle in forward but fast in reverse. I am lost with this but am good with car motors this is a whole new animal. The throttle arm has 3 screws I have no clue what they do. Please help me thanks
. 6540811 50hp 4 cyl