87scarabyxh225

hello everyone...i just baught a 21' 87 scarab I with a 225 yammie on the back.it looks just like the miami vice boat..my controls are clicking and popping and when i took it out the other night for the first time it would only run like 40...i dont know the rpms because tachometer goes to 7000 when it starts...so i have a tachometer issue and when i slowed down to go under a bridge and went to restart,it will die when you give it the juice and the handles pops when you push on it...i can leave it in gear and it will run and got me back to the trailer...my key is mounted in dashboard with tether switch beside it.Im assuming that the bushings in the control are shot hence the popping when i push on it...does anyone know if that control is a 703 or a 704 or a 701???the sticker on the handle says MORSE INCOM on the front...and if i may ask what should the cylinders read for compression???thanx in advance...
Rick