Trojan Boat Forum

I am the new owner of a 1983 Trojan F32 with twin Chrysler 360 engines, The boat has sat for approximately four years. I have the boat running, but I was told there are two rubber impellers that should be changed about every two years to keep my boat from overheating. Is anyone familiar with these impellers and there location?

There in the raw water pump

They should be in the pump that is circled,

Thank you very much I just put a new belts on those units. Do you know of a site where I can order them on line? Are they called raw water pump impellers?

Marinepartssource.com

http://www.marinepartssource.com/chrysl ... -jpump.asp

I recommend that you treat yourself to a copy of Nigel Calder's Boatowner's Mechanical and Electrical Manual at once.

And welcome to the forum!

Yes raw water pump impellers is the name. See the link Jamie posted they can certainly be bought online. I like to order extra gaskets to keep onboard and one extra impeller.

Also you don't want to have the belts too tight. The pumps do not tend to like being side loaded by excessive belt tension.

Be sure to check that the old impeller hasn't ripped any blades off. If blades are missing, be sure to blow them back (backflow the system with low/medium pressure water to push them out), or they will plug things up and cause overheating when you run the engines at speed ...

Congrats on a great boat!

Are you in salt or fresh water? That might change the service requirements. I am in fresh water, and have only changed the impellers once in the 15 years I have owned the boat, and only did that because a bunch of people say you should service them and I hadn't since I bought the boat 10 years earlier... I have only ever had a temperature or overheating issue once but it was not impeller related (after cruising over a weed bog the intake for one engine sucked something up; slowing to idle and turning that engine off to eliminate the suction was enough to let the weeds wash away; after restarting the engine went back to normal temperature immediately).

There were two different models of pumps used in these boats - mine is a Sherwood, I think the other was a Jabsco? They take different impellers, and may require different maintenance schedules.

The essence of this servicing is that if the boat sits for a while, the impellers can take a 'set', and not seal properly within the pump. Also, if the pumps are run dry, overheated, or foreign objects are sucked through the system (eg : sand) pieces of the blades may wear away or break off. If they don't seal right, they can't move water properly. Since yours has sat for 4 years out of the water, there is a greater chance the rubber has dried out and taken on a 'set'. If they dried out, they will be more brittle, and more likely to have chunks break off if you start up. So as one of the other posts says, if you find pieces missing when you pull them, you should back flush the system to try to find and clean out those pieces, so they aren't clogging something downstream.

I know someone who diligently removes his impellers every winter and stores them in a jar of mineral oil, then re-installs them every spring. His view is that this keeps them from taking on a set, and keeps them from drying out and going hard. As I sad, I have only pulled and changed mine once in 15 years. It has worked for me, but 'your mileage may vary'.

Thank you all very much for taking your time to help me with my boat. I ordered a copy of Nigel Calder's Boatowner's Mechanical and Electrical Manual, and I am removing the impellers. Hopefully they are intact and I will not have to back flush the system or I will need some more help. Thanks again, Work in progress
Kevin

when you go to change impeller (assuming sherwood g-5 to g-7)check for any end play in bearings. If so it is fairly simple to rebuild the whole pump, the bearings can be found cheap at bearing supply house, seal not so much, but an easy rebuild with diagram one can get of the net.

I did it simply without a press but a press is helpful, I have one now, just be careful and think your way through it. The hardest part is getting the pully off as it is a press fit with set screws also.

In my opinion most any pump can be simply rebuilt in total if needed. Notice I said most.

Thanks for your help and you all continue to be very helpful, I am now in the process of getting a remanufactured transmission for the starboard engine. My transmission got stuck in forward gear and could not be serviced by the local transmission shop because they could not get the case open. I could not recall if the starboard engine is LH or RH rotation I believe it is right hand, but the shop needs to know before they ship my transmission. I also have some wobble on the starboard drive shaft, I have a friend who is a diver who dove and looked at the prop and said it looked ok. Is the drive shaft something that can be straightened or does it need to be replaced; if so does anyone know a good place to purchase one.

Thanks,
Kevin

The starboard should be a right hand rotation looking at flywheel it would be rotating clockwise( reverse rotation ). Yon can also look at the pump on the old trans , unless of course they removed it then you don't know what direction it was .

There was a thread on rotation in the last week or so . ( it got a little heated )

Thanks but the Transmission has been removed already, I can probably look at someone else boat and see what direction theirs turns. Did you know anything about the drive shaft ?