Intermittent Loss of Power After Hitting Submerged Object

chemeguy

Recruit
Joined
Jan 5, 2003
Messages
3
Everything was working fine with the motor on my little houseboat until...I hit a submergered object at very, very low speeds (2-3 mph - 1500 RPM). After stopping, raising the motor and inspecting (everything looked fine) I continued at low speed and experienced some intermittent loss of power (few seconds fine, drop for a few seconds). This was accompanied by a small amount of vibration felt through the steerling whell during the rpm loss. As I continued back to my marina, the problem seemed to rectify itself...in fact it totally went away after a few minutes.<br /><br />On the next trip out, I experienced the same problem for a few minutes while coming up to speed and again it went away until I had stopped and reversed a few times. Then it came back only to go away again once moving forward for a few minutes.<br /><br />Doesn't seem to matter if the throttle is open a little or a lot. Any help would be appreciated.<br /><br />Thanks.
 
D

DJ

Guest
Re: Intermittent Loss of Power After Hitting Submerged Object

chemeguy,<br /><br />I would be looking for a loose or suspect connection somewhere.
 

Hooty

Rear Admiral
Joined
Oct 2, 2001
Messages
4,496
Re: Intermittent Loss of Power After Hitting Submerged Object

Not knowing what engine and size makes it kinda tough but you may have spun a prop hub. If the engine revs up and the boat slows down, that's where I'd look.<br /><br />c/6<br /><br />Hooty
 

miloman

Lieutenant Junior Grade
Joined
Nov 3, 2002
Messages
1,181
Re: Intermittent Loss of Power After Hitting Submerged Object

from what youve said it seems that you damaged yuor prop hub
 

chemeguy

Recruit
Joined
Jan 5, 2003
Messages
3
Re: Intermittent Loss of Power After Hitting Submerged Object

The motor is a 1995 90 HP Nissan.<br /><br />As for the way the this happens. At higher RPMs there is a noticeable but minor decrease in RPM when this occurs. When the RPM is lower, the vibrations are greater and the RPM loss is almost unnoticable.<br /><br />Thank for the help. I will look for loose connections and take the prop off for inspection. Any further input is still appreciated of course.
 

Mumblerone

Petty Officer 1st Class
Joined
May 12, 2002
Messages
344
Re: Intermittent Loss of Power After Hitting Submerged Object

When you test the prop...be sure to mark it with a grease pencil. One mark on the prop, and the other on the prop hub. If the marks still line up after the test ride and you have the same occurance...the prop is OK. ;)
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: Intermittent Loss of Power After Hitting Submerged Object

Hi chemeguy...<br /><br />While you have the prop off, check the run out on the prop shaft. May as well check the lower unit also. Drain the gear lube and see what it looks like. Even at low rpms, stuff can happen to lower units. When you hit, did the engine stall?<br />Good Luck<br /><br />Jim
 

chemeguy

Recruit
Joined
Jan 5, 2003
Messages
3
Re: Intermittent Loss of Power After Hitting Submerged Object

Hi OutboardJim,<br /><br />The motor did not stall. Just a horrible sound of steel against something hard and it was over in the blink of an eye.
 
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