Bumping noise in OMC Cobra outdrive

[dinjun]

I just bought a 1988 Bayliner 2159 with a 3.0 OMC engine and Cobra outdrive. The engine runs very smooth but when placed into gear gets a bumping noise at the outdrive. The boat shop said it could be the prop, but it checks out fine. I was hoping someone else might have a idea of what it could be and how much trouble it is to repair...

 

[olbuddyjack]

Re: Bumping noise in OMC Cobra outdrive

Is it a steady bump or intermittent? Could be a bent prop shaft, chipped lower gear or dog clutch slipping. Everything in the drive spins with the engine in neutral except the prop shaft so I would look around down there.

 

[seahorse5]

Re: Bumping noise in OMC Cobra outdrive

The bumping noise may be the clutch dog jumping out of the fwd. gear. Most of the time it is due to wear, stiff or mis-adjusted linkage, cables, etc., or poor shifting practices.<br /><br />On your 17 year old boat, it is probably a combination of all 3.<br /><br />Have it checked by a QUALIFIED person and most likely you will need gear and clutch dog replacement.