Need help finding correct water pump impeller please!

07Tahoe

Seaman Apprentice
Joined
Nov 17, 2017
Messages
31
Hello all,

Looking for help. I am having a hard time tracking down the right water pump impeller. Please see attached pictures of my outboard engine id plate and old impeller. According to that serial number this is supposed to be a 1984 Chrysler/Force 85 HP. I need the correct sized water pump impeller for it. Here are the ball park measurements of the needed impeller that I took off the old one:


Inside bore diameter: .875" (7/8")
Height approx: 1.300"
O.D. approx: 2.250"

All my internet searches keep throwing a part #47-803630T with the following measurements which is not going to work:

Inside bore diameter: .820"
Height: 1.750"
OD 2.250"

I don't know if I have an odd ball lower unit or what is going on. Thank you for any help you can provide.

John




 

kbh121956

Chief Petty Officer
Joined
Jun 30, 2013
Messages
474
Ebay has them, type in your number of 47-89984 3 anywhere from 20 - 30 dollars.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
F523065-1 is the Force/Chrysler part #
This site should have it.
Or e-bay.

The # on your part is a Mercury #

It looks like the impeller is missing parts.
Very important to find them.
Take the thermostat housing off and backflush the system.
​See if they flush out.
Can cause a blockage and overheat???

Oh yea Welcome!!
 

Nordin

Commander
Joined
Jun 12, 2010
Messages
2,428
Maxrules (Mastertech) has an aftermarket, # MTM89984 17,25 dollar.
 

07Tahoe

Seaman Apprentice
Joined
Nov 17, 2017
Messages
31
Thank you for all the responses and the welcome. I am still confused why when I look up the part number by the serial number it does not match what is physically on my lower unit. Is it possible the lower unit is from another power head? Why would the impeller be bigger than what the parts book lists? Is there any way to identify the true make and specs of the lower unit? It has a 2 piece 7/8" drive shaft, plastic pump housing with stainless cup. This has me walking on egg shells worrying about buying the correct parts for the lower unit.I did pull the thermostat and checked the operation of it and back flushed the water passage. Only impeller debris I found were stuck in the pump housing cavities and they all matched up to the impeller and are accounted for. I bought this engine used recently and mounted it to my Bass Tracker boat. It fired up and ran real good except for the impeller issue.

Also, should I worry about replacing the timing belt or you think it should be ok? Are they know to "rot out" and go bad after time? This is my first outboard with such a setup. Thanks again for the advice!
 

kbh121956

Chief Petty Officer
Joined
Jun 30, 2013
Messages
474
Your timing belt should be fine. Look for cracks on the inside of the belt. I wouldn't replace it unless it needs it. To replace it you will need to pull the flywheel off.
 

kbh121956

Chief Petty Officer
Joined
Jun 30, 2013
Messages
474
Also both jerryjerry05 and Nordin are very good. Those part number that they gave you for the impeller will be correct.
 

07Tahoe

Seaman Apprentice
Joined
Nov 17, 2017
Messages
31
IF??? you have a 2 piece drive shaft???
​Then the lower unit is not the OEM.

​They started using the 2 piece shaft sometime in 89.
The impeller and housing are different.
​The stainless cup uses a smaller impeller.
F694065 is the part # for that drive.



Yeah here is some pictures of everything. I was talking with kbh121956 in PM's. He has high regards for you guys btw. He suggested checking out Amazon for the part # 47-89984 3 impeller. The seller had the exact dimensions listed that I was looking for and also had pictures with the micrometer showing it at the link below. Can you believe I ordered the part yesterday at 3:30 pm. Paid #13.63 for the part. It offered shipping for 6 bucks to be delivered on the 27th or for 10 bucks I would have it by 9 pm Sunday. I went with the 10 bucks, figuring there was no way that was going to happen and I should at least get a refund on the shipping. I never ordered an internal part for an outboard motor that would show up that fasat at that kind of price. It arrived at my door at 12:30 pm. That's under 24 hours shipping! ON A SUNDAY! Holy crap!!!! It says on the shipping label it came from Kentucky?? I can't believe it. I am absolutely floored by this! And happy! :) Eat your heart out eBay!!!!

https://www.amazon.com/47-89984-47-...coding=UTF8&psc=1&refRID=F93RSPRMS6HZ76YMTTWP

You can see in my pics it looks like a perfect match. Any other thoughts of the items in the pictures and other part numbers to help identify this lower unit? Thanks again all!!

















 

kbh121956

Chief Petty Officer
Joined
Jun 30, 2013
Messages
474
I have never seen a lower unit like this. Jerryjerry05 is correct. The man knows his outboards.
 

07Tahoe

Seaman Apprentice
Joined
Nov 17, 2017
Messages
31
I put this in the river and ran it last night. Idles fine, no overheating issues at all. Lots of stuttering under load though. Will hop up on plane under full throttle and take off but still stammers/misses intermittently through the entire RPM range except for idle. I have a feeling it is the spark plugs. I will replace them and see how she runs.

I also found this while I was installing the lower unit. This is definitely a custom hack job?








And here she is mounted up on Darth Vader. (That's my boat's name.)





 

Nordin

Commander
Joined
Jun 12, 2010
Messages
2,428
jerryjerry is right, that LU is not OEM for a 1984 year 85Hp.
The 2 piece drivshaft came in 1989 and under the Force brand.
Your engine suppose to be a Chrysler, BUT Chrysler sold the OB business in 1984-85 to US marine and then it was under the Force by US Marine brand.

The mod at your LU is made for making this LU to fit your midleg because the 2 piece LU has another housing for the impeller.

BTW Be careful with the bellow at the shift shaft, it act as a seal to the gearoil and is N/A.
 

07Tahoe

Seaman Apprentice
Joined
Nov 17, 2017
Messages
31
jerryjerry is right, that LU is not OEM for a 1984 year 85Hp.
The 2 piece drivshaft came in 1989 and under the Force brand.
Your engine suppose to be a Chrysler, BUT Chrysler sold the OB business in 1984-85 to US marine and then it was under the Force by US Marine brand.

The mod at your LU is made for making this LU to fit your midleg because the 2 piece LU has another housing for the impeller.

BTW Be careful with the bellow at the shift shaft, it act as a seal to the gearoil and is N/A.


Oh dang! I did not know that about the bellows. This one seems in good shape. Thanks for the heads up!
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
Pack the shift shaft bellows in grease when putting it back on.
Will keep it soft and supple and maybe not go bad?

​GEEZ!! that's quite a hack job on that lower unit.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
He might have one of FrankA's motors??

You remove a decal of a Mermaid?

Frank Acampora lived in south eastern PA.
 
Last edited:

07Tahoe

Seaman Apprentice
Joined
Nov 17, 2017
Messages
31
He might have one of FrankA's motors??

You remove a decal of a Mermaid?

Frank Acampora lived in south eastern PA.



Yes it did I took the decals off it. You seem to know more about this engine than I do! Small world!! I bought it off some dude on CL. I like in King of Prussia in SE PA.

Now I am trying to figure out what plugs it should have, the parts books don't seem to list them. It currently has NGK BUHW's it right now. Is that the correct plug?
 
Top