I had recently seen articles written "challenging" anyone to explain how to change an impeller on the Passage 450. I read them and registered them but did little to research it UNTIL. Prior to seeting out to the Southern Cal rendevous I thought it might be a good idea to "check" the condition of the impeller. ANSWER: YOU CAN'T, even though it is a required maintenance item in the Yanmar manual. (does this affect the warranty?) After listening to the diesel engine session given by the great guys at the Boatswain's Locker, I just had to ask the question; "How does one change the impeller on a Passage 450?"; ANSWER: You either REMOVE A MOTOR MOUNT OR REMOVE ALTERNATOR- - OR BOTH, to gain physical contact with the pump. YOU STILL CANNOT SEE IT! Then if your lucky enough to get the cover plate off the pump YOU STILL CANNOT GET THE IMPELLER OUT and even if you do you can't see to get the new one back in. According to the experts, your better off taking off the pump to get the impeller out! The spare impellers I purchased to have on board in case of a failure will probably rot in the packaging; they are useless. I would hope that if I ever experience a failure at sea that I have a spare pump, calm seas, and about 7 or 8 hours of time in order to change the impeller. I now have a new understanding of why true cruisers take a long hard look at engine access before they buy. My Passage 42 allowed the change (or inspection) of the impeller in about 10 or 15 minutes. Shame on me. Live and learn. By the way, the starter motor is an even bigger horror story! If anyone has a mechanically inclined relative with several addition joints in each arm and the ability to see around corners please get them in touch with me. Have I got a job for them!
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It takes 90 minutes
You're correct that changing the impeller on the 78HP Yanmar in a 450 is a pig of a job. The easiest way is to get at it by removing the alternator then reaching around and doing everything by feel. I don't try it myself as I have never had a chance to see what it looks like! I have it done once a year by some poor sod of an unwitting mechanic. Once it took two hours, once 90 minutes. I installed a Speedseal cover, which does make it a tiny bit easier. Advice: if you are ever at a boat show where there is a Yanmar 4JH2 engine on display, take A LOT of pictures of the impeller cover so you will know what it looks like if you ever need to change it in an emergency. I missed my chance to do so and have regretted it ever since. (The Yanmar workshop manual is no help as it has very poor illustrations.) Good luck!
You're correct that changing the impeller on the 78HP Yanmar in a 450 is a pig of a job. The easiest way is to get at it by removing the alternator then reaching around and doing everything by feel. I don't try it myself as I have never had a chance to see what it looks like! I have it done once a year by some poor sod of an unwitting mechanic. Once it took two hours, once 90 minutes. I installed a Speedseal cover, which does make it a tiny bit easier. Advice: if you are ever at a boat show where there is a Yanmar 4JH2 engine on display, take A LOT of pictures of the impeller cover so you will know what it looks like if you ever need to change it in an emergency. I missed my chance to do so and have regretted it ever since. (The Yanmar workshop manual is no help as it has very poor illustrations.) Good luck!
H450 Yanmar Impeller
Lots of businesses claim to have Yanmar mechanics. Most don't attend annual engine training updates. I can attest to being able to change the impeller in question in approximately 48 minutes. The first time took roughly 90 minutes, but after installing a speed seal and removing the alternator to get at the pump, time was improved to 48 minutes. This is not a repair to be experienced for the first time underway. The speed seal and first learning curve should be done on a cold engine in the slip. While many will throw up their hands and howl in dispair, a bit of can-do attitude and determination will leave those people behind on the beach. A good work lamp and a mirror is also an aid to expedite the process. I must be related to the poor sod of an unwitting mechanic. Funny how all that money and education that most high rollers have doesn't prepare them for the everyday chores of boat ownership.
Lots of businesses claim to have Yanmar mechanics. Most don't attend annual engine training updates. I can attest to being able to change the impeller in question in approximately 48 minutes. The first time took roughly 90 minutes, but after installing a speed seal and removing the alternator to get at the pump, time was improved to 48 minutes. This is not a repair to be experienced for the first time underway. The speed seal and first learning curve should be done on a cold engine in the slip. While many will throw up their hands and howl in dispair, a bit of can-do attitude and determination will leave those people behind on the beach. A good work lamp and a mirror is also an aid to expedite the process. I must be related to the poor sod of an unwitting mechanic. Funny how all that money and education that most high rollers have doesn't prepare them for the everyday chores of boat ownership.
Thanks for the input
Thanks for the replies to my post. I am now in search of a source of the "speed seal" cover for the raw water pump. I guess I am a bit "spoiled" by my past experiences with my P-42. The "task" was a 20 minute job and you could actually inspect the pump and impeller visually to make sure the housing was in good shape and the impeller fins were installed properly. To Phil, it is a Yanmar engine. I'll go at the change with a "can do" attitude at the dock. If I have a failure at sea I can guarantee an entirely different attitude. Thanks to all for the help here.
Thanks for the replies to my post. I am now in search of a source of the "speed seal" cover for the raw water pump. I guess I am a bit "spoiled" by my past experiences with my P-42. The "task" was a 20 minute job and you could actually inspect the pump and impeller visually to make sure the housing was in good shape and the impeller fins were installed properly. To Phil, it is a Yanmar engine. I'll go at the change with a "can do" attitude at the dock. If I have a failure at sea I can guarantee an entirely different attitude. Thanks to all for the help here.
Glad I have a Volvo Now!
I always wished I had gotten my boat equipped with the Yanmar instead of the Volvo since Yanmar parts are much easier to come by when traveling. But after changing my impeller in less then 10 minutes sitting on busy Lake Erie, I am really glad I have the Volvo after listening to the horror stories of changing an often needed item such as the raw water impeller. I must admit however, if I ever have to change the alternator, I may have to take out the engine.
I always wished I had gotten my boat equipped with the Yanmar instead of the Volvo since Yanmar parts are much easier to come by when traveling. But after changing my impeller in less then 10 minutes sitting on busy Lake Erie, I am really glad I have the Volvo after listening to the horror stories of changing an often needed item such as the raw water impeller. I must admit however, if I ever have to change the alternator, I may have to take out the engine.
I have done it twice now
I am not bragging but I have replaced my alternator twice now. Yes it is somewhat simular to the impeller on the Yanmar as you must work blind on the mounting bolts. Sounds like our Volvo is a lot more servicable. I guess Hunter realized their mistake about access when they came out with the new 420 as you can get access in the head. Volvo mechanics don't visit traning required on our engine, most authorized Volvo dealers say HUH? when you mention our engine!
I am not bragging but I have replaced my alternator twice now. Yes it is somewhat simular to the impeller on the Yanmar as you must work blind on the mounting bolts. Sounds like our Volvo is a lot more servicable. I guess Hunter realized their mistake about access when they came out with the new 420 as you can get access in the head. Volvo mechanics don't visit traning required on our engine, most authorized Volvo dealers say HUH? when you mention our engine!
3JH2E Yanmar on 376 isn't much better
My 376 Hunter has a 3JH2E Yanmar and I have to remove the starter to get to the impeller. I guess it will be a job for my mechanic I also just paid my mechanic to install a special relay to increase voltage at the starter, because the length of the run from the ignition key was too long and caused a voltage drop and the engine would not crank. Where was the engineer on that one?
My 376 Hunter has a 3JH2E Yanmar and I have to remove the starter to get to the impeller. I guess it will be a job for my mechanic I also just paid my mechanic to install a special relay to increase voltage at the starter, because the length of the run from the ignition key was too long and caused a voltage drop and the engine would not crank. Where was the engineer on that one?
The Yanmar JH Pump is different
I ordered and received a "SpeedSeal" kit for the Yanmar 4JH in my 450. It is quite humerous (tongue in cheek) that the instructions sent with the kit actually show a gentleman "blind folded" and in the process of changing the impeller. Was the photo shot at Hunter with the "engineer" who designed this installation? In any case, just wanted to let everyone know that the pump on the "JH" series has the "O" ring in the face of the pumpand NOT in the cover. This makes the inspection and changing of the gasket a tad more challenging since it remains "unseen". A bit of insult has been added to injury. I am grinning (and bearing) whilst I install this new adition.
I ordered and received a "SpeedSeal" kit for the Yanmar 4JH in my 450. It is quite humerous (tongue in cheek) that the instructions sent with the kit actually show a gentleman "blind folded" and in the process of changing the impeller. Was the photo shot at Hunter with the "engineer" who designed this installation? In any case, just wanted to let everyone know that the pump on the "JH" series has the "O" ring in the face of the pumpand NOT in the cover. This makes the inspection and changing of the gasket a tad more challenging since it remains "unseen". A bit of insult has been added to injury. I am grinning (and bearing) whilst I install this new adition.
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