Westerbeke impeller issue...

Pulled the impeller from my Westerbeke genset today. Location made it a pain in the butt just to get the cover off but off it came. Impeller was missing a vane but found it easily in the heat exchanger. Went to put in a new impeller, same make (Johnson) same model number (B10-B1), and the fun began. Can get it in about 75% of the way and then nothing. Compared old and new and see that the metal cross bar in the old one looks somewhat smaller than the new one, picture provided. Happen to have a spare pump so I tried to put the new impeller in it. Stopped at about the same point but when I pulled the vanes back a bit it went right in. Took my new found skill and knowledge down to the engine and spent the next 2 1/2 hours trying to duplicate the install with no luck. Everything is smooth inside the pump, nothing that appears out of order, nothing that should prevent full insertion. The impeller is lubed and slides in and out with relative ease. Just not all the way in. I just cant get it past the point where the cross bar enters the cutout on the shaft. Everyone says to use an electrical tie but didn't have any onboard. Will bring some but just haven't gotten there yet.

Any comments appreciated.

Metal bar APPEARS to be larger in diameter.

check pump shaft for burrs or wear inside slot.

The newer pumps have a smaller "crossbar" or pin than the older pumps. If your pump number is 48080 you have the smaller "crossbar". Easy fix, push the pin out of the old impeller and place in new one. Impellers are the same,

Bar is noticeably smaller but...it went in the same model spare pump. Measured the slot in the active and spare pump as best I could and they seem to be the same size. No burrs.

sunchaser said:

The newer pumps have a smaller "crossbar" or pin than the older pumps. If your pump number is 48080 you have the smaller "crossbar". Easy fix, push the pin out of the old impeller and place in new one. Impellers are the same,

Click to expand...

You mean the newer pump has a smaller slot not cross bar, correct? I believe that the spare pump is the original that the PO replaced before cruising 3-4 years ago. I will check the pump number. As for using the old pin, it looks pretty tired. I may be seeing things but it sort of looks like it has a tiny bit of a bend to it. The picture sort of shows it I think. Is it safe to reuse this part? Seems like it would undergo a lot of strain. Also, it would seems that the hole in the sides of the impeller would be bigger as well which would leave the old cross bar loose?

sunchaser said:

The newer pumps have a smaller "crossbar" or pin than the older pumps. If your pump number is 48080 you have the smaller "crossbar". Easy fix, push the pin out of the old impeller and place in new one. Impellers are the same,

Click to expand...

That is the exact situation and fix that I had on my westerbeke 8 k gen set

Where the pin lodges into the Impaler it is of a larger-diameter. It is reduced in diameter in the center

sunchaser said:

The newer pumps have a smaller "crossbar" or pin than the older pumps. If your pump number is 48080 you have the smaller "crossbar". Easy fix, push the pin out of the old impeller and place in new one. Impellers are the same,

Click to expand...

This is what I have to do with my Westerbeke.

I've been using the same pin for years, so I wouldn't worry much about durability. If it snaps eventually I'll use a stainless screw, or pin, or nail or whatever. Just one more boat thing to fiddle with.

Well now, not going crazy and not alone. Thanks for the comments and fix which I will use. Going to call Westerbeke and Johnson today and see what they say as well. Changing the diameter of the pin on the same model number part seems.....rude. Maybe they have some magic part number for a matching one that no on knows about. Hey, could happen. It won't but it could.

I would think that it is a stainless steel pin but my pic looks like it is brass but that seems like it would be pretty soft?

Yep what sunchaser said! Impellers have been a thorn in my side.

firstbase said:

I would think that it is a stainless steel pin but my pic looks like it is brass but that seems like it would be pretty soft?

Click to expand...

Without getting into the metallurgy of designing pins, retainers, seals, gears etc, just push the pin out out of old just removed impeller and place in new. Remembering that the next mpeller you purchase will be of two pin designs. Order the one with pin that matches your operating pump - not the (possibly leaking?) older used pump.

Impellers are not long lived. Get used to changing them. Preferably before they fail. Welcome to the marine world.

Thanks. Apologies for being a pain. Part of the issue is that there are confusing and conflicting Part #'s and "Replaces ****" listed online. Seems to be, as you say, two different versions. I ordered both will return the wrong one. Thanks for the help!

firstbase said:

Thanks. Apologies for being a pain. Part of the issue is that there are confusing and conflicting Part #'s and "Replaces ****" listed online. Seems to be, as you say, two different versions. I ordered both will return the wrong one. Thanks for the help!

Click to expand...

Order he one that matches your pump cover number. Get genuine Westerbeke not a Chinese knockoff or you could end up with yet another pin design.

I finally sorted it out and received the correct impeller. Operator error. Since a new pump replaced the old one I assumed it was exactly the same. It wasn't. Slight difference, the size of that pin in the same size/profile impeller. Once I realized and found the pump model number as suggested above I tracked it down. Now have a spare pump with a different size impeller that I have to remember but issue solved. Thanks to everyone for putting up with me.