JohnP wrote:
1. If you have a Lehman 120, has your original raw water pump drive failed?
2. If you have changed out to the Johnson Pump,* was your original drive cracked?
3. If not and you still have it do you want to sell it?
1.* On the port engine, almost, but not quite.* This was at about 2,500 hours.* The starboard engine was fine.
2.* Yes, that's how we found the port drive was almost shot.
3.* No, we retained the drive and pump off the starboard engine as a spare.*
If you are thinking to try to get a second drive to have as a spare my advice is to forget the Lehman drive and Jabsco pump altogether and convert to a Johnson pump.* The problem is that when the Lehman drive fails you immediately lose your raw water cooling.* The engine will immediately and rapidly overheat and unless you catch it right away before the temperature gets too high, you'll most likely kill the engine--- the head gasket will go pretty quick and the chances are good the head will warp.
Remember, the temperature overheat alarm (if it works at all) will most likely sound to tell you that the engine has just catastrophically overheated and the engine is toast.* That's what alarms are for, right?--- to tell you that the piece of equipment they're monitoring has just failed.
* That's why we have a timer at the helm that dings every five minutes to remind us to check the engine instruments--- it's very easy to get distracted on a boat with stuff like whales and the scenery and (up here) looking out for debris in the water.
If you have a single-engine boat, carrying a spare drive is a good idea BUT..... do you want to be down in the engine room doing a major project like changing out the drive, switching pump over to the spare drive, and dealing with the hoses with the boat rocking and rolling in a seaway?
Better, I think, to simply change to a Johnson pump and eliminate the problem once and for all.* If the original pump and drive are okay, keep them as your spare.* You will want to keep the original pump output hose with the Lehman setup, too, since it will be shorter than the one on the Johnson.* Saves you having to cut a new hose or cut down the hose from the Johnson pump.
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