Hammer knocking noise when in gear over 3000 rpm
#1
Registered
Thread Starter
Join Date: Dec 2001
Location: Rapid City SD
Posts: 809
Likes: 0
Received 0 Likes
on
0 Posts
Hammer knocking noise when in gear over 3000 rpm
Helping a friend out with a 26ft cabin boat with 350 carb motor, Bravo3. At the dock on the trailer, if you rev the motor upto 5000, there is no extra noises. When you put it in gear at about 2500 it starts with kind of a exhaust leak noise but as you throttle up it starts sounding like a hammer hitting in the back, by the coupler & drive shaft. We pulled the drive and checked the gimbal and u-joints and found no problems. We can shift the drive and spin the drive shaft over by hand smoothly. Any ideas what to try? Coupler, flywheel.
I have a spare bravo1 off my 502 that we could use to try and isolate the problem. Will it fit on the 350, Bravo3 mount?
I have a spare bravo1 off my 502 that we could use to try and isolate the problem. Will it fit on the 350, Bravo3 mount?
#2
Registered
What year engine?
#4
Registered
Thread Starter
Join Date: Dec 2001
Location: Rapid City SD
Posts: 809
Likes: 0
Received 0 Likes
on
0 Posts
Not sure about year but guessing around 2006-2008. I forgot the mention he said he hit a sand bar with the prop earlier in the weekend, and an hour before the noise, it quit running while under power, but started right up. Guessing that is when the sound started, but he was idling then to go get gas so he wouldn't have had the noise.
#10
Registered
iTrader: (7)
If insured have him contact his agent. I've had a couple covered over the years. One was a sand bar and other was a dead head at over 80 mph and that one took the drive right clean off. That one I had my hands full trying to get the boat under control.