Question for the Pro's!!!!

I have bought a 88 glasstream bass elite with a 150 yamaha 2 stroke on the back. The boat does wonderful out of the hole, but when you begin to reach about 4200 rpms the motor seems to want to start jumping rpms and the prop threatens to kick out.....I cannot trim the motor up and inch or it will kick out(causing the motor to over rev) I still have control as soon as i back off the throttle its pulling. Some would say lower unit, but out of the hole I can stand the boat on end I think it would give there before giving while already moving. The boat also want's to start pulling rpms and slowing down when trying to make the simplest turns at medium speeds, the prop is the recommended pitch of 21 though it is an alluminum prop and could possibly flex??? I don't know what's going on. The hub in the prop appeared to be in good shape with no missing chunks of rubber. The gear on both the motor and the prop are also in good shape and with the motor trimmed down the bottom of the boat his exactly half way on level with the water intake jackets. Please Help!!!

[Timmstng67]

This Might help.

Hi

I am not a pro but have been Boating for many years, It sounds to me like the motor is mounted to high, I am not sure what type of hull is on your boat but once on plane from what you have described about the hight of your water intake area in reference to the bottom of the boat it sounds like the cavitation plate "this is the thin wide area just above the water intakes" would be out of the water which would cause it to blow out or over rev. if the cavitation plate is out of the water when on plane it may be the cause of your problem. As I said I am not a Pro but something to take a look at .

Tim