OMC 120HP - Water Pump Replacement

[Litetwin4]

I have an OMC 120HP motor with a OMC cobra out drive (mid eighties boat) and I am not getting water flow through the motor with the muffs on and the engine running.

I am thinking the water pump in the out drive is shot.

Can anyone provide advice on what the problem is ?

How hard is it to change the water pump?

Thanks

 

[Don S]

Re: OMC 120HP - Water Pump Replacement

Are you sure you have a 120 or a Cobra drive? OMC didn't use a 120 with the Cobra drive.
If it actually is a Cobra, the pump impeller is easy to change, just pull the plastic cover off the back of the drive. The pump is under it.

EDIT: Just looked at your other thread, if you have select trim, you DO NOT have a Cobra drive, you have a stringer drive. That pump is a job.

 

[Litetwin4]

Re: OMC 120HP - Water Pump Replacement

I just went out and looked at my out drive and it has the word "OMC Stern Drive" on it.

The boat is an 1984 Starcraft bow rider. If the stringer is the older model, I think you could be right.

If it is a stringer outdrive, what does it entail to replace the water pump?

I am engineer by trade so I am mechanically inclined. Usually I can perform most repairs myself.

However, if it requires special tools or is really tricky to reassemble and adjust properly I usually will let a trained person perform the repair.

Thanks for your time.

 

[zbnutcase]

Re: OMC 120HP - Water Pump Replacement

Yup, you got a stringer mount, and the water pump is located at the bottom of the upper gearcase. Job not that difficult, but must remove drive then seperate upper from lower. Get a manual, read it, then decide if its a job for you.

 

[superbenk]

Re: OMC 120HP - Water Pump Replacement

There's a manual you can download & a thread where I posted pics of the job in the Adults Only section at the top of this forum. It's not a difficult job, but it will take a good bit of time and effort. Plan on some bolts & the housing to be tough to remove due to corrosion. Check the swivel bearing seals where the top gear case swivels on the lower gear case and replace if they're chewed up or in rough shape.

 

[Litetwin4]

Re: OMC 120HP - Water Pump Replacement

Here is a good link which includes pictures of water pump replacement on a stringer outdrive. For anyone else that is interested.

http://forums.iboats.com/showthread.php?t=378358