force 150 vibration

[1bernerd]

Vibration starts at about 1500 to 2000, shakes the whole boat. Idles perfect,problem started when boat was loaned out. Prop was dinged up, but not to bad. Replaced prop, perfect compression,fires on all 5,prop shaft appears not to be bent, new powerhead 3 years ago. 2 mechanics and a year and a half later still dont have a boat to use please help.

 

[12Footer]

Re: force 150 vibration

You may have a bent prop shaft. If this guy whacked your prop, he probably did a number on the shaft too. Stand behind the boat,and turn the prop by hand,and note if the propshaft wobbles in it's orbit.If so, the gearcase must be torn down and propshaft replaced. Check all transom mounting bolts also.

 

[sony2001]

Re: force 150 vibration

Sounds like an intermittent electrical problem. There is a loose electrical connection. Could be as simple as a loose CD wire that came about from the foot hitting the bottom of the lake. I bet a cylinder is not always working.

 

[Acker1]

Re: force 150 vibration

Hello, I had the same problem, replaced prop and everything on a 96 40h.p. model. I found out it was an adapter plate gasket that had blown out. The adapter plate was cracked as well. $170.00 later in parts and about 1 hour of labor I was back on the water. The adapter plate is the plate at the bottom of the power head, that is inbetween the head and the leg. It is actually what directs the exhaust and the water through and out of the engine. If it is blown out, water gets sucked into the bottom clyinder, and if it is blown bad enough, water will come out into the housing. Do not run until fixed. Vibration is a very bad thing on Forces especially.