In some other thread I was asked about the Johnson replacement pump for the FL120s original Lehman drive coupler/Jabsco impeller raw water pump setup. As I learned a long time ago from Bob Smith at American Diesel, who designed the drive coupler when he was at Lehman in New Jersey, the drive coupler will eventually break. It's just a matter of when. New ones are no longer available and a weld fix will not last long.
The solution, as recommended by Bob and any diesel shop with experience with these engines, is to install a new Johnson pump in place of the orignal setup.
I took this photo at the boat today. Unfortunately we do not have the pump part number on the boat anywhere obvious. But American Diesel can tell you and your diesel shop should be able to as well.
We have the 1" pump on our engines. This is actually the pump required for the FL135. The pump normally put on an FL120 is the 3/4" pump, which looks the same. But the 1" pump provides more flow and this can be advantageous with regards to cooling the transmission. It definitely is with ours.
The clearance between the fuel injection pump drain plug and the upper raw water outflow elbow is greater than it appears in the photo, but not much greater. This makes it a bit more tricky to change the oil in the injection pump every 50 hours. But I came up with a split water hose funnel sort of thing that makes the job actually quite easy despite the tight clearance.
The solution, as recommended by Bob and any diesel shop with experience with these engines, is to install a new Johnson pump in place of the orignal setup.
I took this photo at the boat today. Unfortunately we do not have the pump part number on the boat anywhere obvious. But American Diesel can tell you and your diesel shop should be able to as well.
We have the 1" pump on our engines. This is actually the pump required for the FL135. The pump normally put on an FL120 is the 3/4" pump, which looks the same. But the 1" pump provides more flow and this can be advantageous with regards to cooling the transmission. It definitely is with ours.
The clearance between the fuel injection pump drain plug and the upper raw water outflow elbow is greater than it appears in the photo, but not much greater. This makes it a bit more tricky to change the oil in the injection pump every 50 hours. But I came up with a split water hose funnel sort of thing that makes the job actually quite easy despite the tight clearance.