1961 Mercury 100 (9.8)

Reg312

Petty Officer 2nd Class
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Jul 12, 2009
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139
My Merc 9.8 doesn't pump water. I'm attempting to change the pump / impeller but have run into a little road block. Yes --- I know i Should get a manual, but at $100 is a little out of my budget. I've attached a picture that hopefully will help. Hole "A" measures approx. 1/2 dia by 2" deep and looks to be lined with a plastic sleeve. The end of the sleeve looks torn or ripped and when I put liquid thru it it runs out the water intake. I really can't see what this port does as when the cover is on it looks like its blocked anyways. Hole "B" is the fresh water rinse and when liquid is poured thru it it also exits at the water intake. So how do I get to the impeller to check / change it? Any help would be appreciated.
 

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Reg312

Petty Officer 2nd Class
Joined
Jul 12, 2009
Messages
139
Re: 1961 Mercury 100 (9.8)

This must be a tough one. So, does anyone have a manual that they can copy and send the instructions to change the impeller on the Merc. I've googled on and off for over a month now with very little results.
 

turtles11756

Petty Officer 1st Class
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Dec 5, 2007
Messages
260
Re: 1961 Mercury 100 (9.8)

are you missing a part ? water tube ? the parts manual is available oldmercs.com $17.00. i have the service manual here and will help if i find impeller change. serial # and HP ? of that engine. the water pump removes as a cartridge with a special tool to release a lock ring ?. try the forums at AOMC.COM antique outboard motor club they will take you thru it
 

Reg312

Petty Officer 2nd Class
Joined
Jul 12, 2009
Messages
139
Re: 1961 Mercury 100 (9.8)

Can't tell you what parts I'm missing. I did see the parts manual at a decent price, but figured if I could find a good repair manual, a parts schematic would be in it. All I've done so far is remove the lower unit and that cover. I found someone posting impeller replace on a 1963 9.8 but he says after pulling the lower unit (which I'm assuming is the part held on with 2 bolts that houses the prop) there are 2 1/4 - 28 nuts holding on the pump cover. Wherever those 2 nuts are --- I have NO idea. ANYWAYS -- 1961 mercury 100 (9.8) serial #1455124. Where the heck is that cartridge? All i see on the lower unit is water passages and the gearing that connects the lower unit to the upper part for the prop to turn. Thanks
 

turtles11756

Petty Officer 1st Class
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Dec 5, 2007
Messages
260
Re: 1961 Mercury 100 (9.8)

a 1961' is totally different to service. water pump cartridge: "by inserting drive end into recesses of lock ring and turning clockwise(left hand thread water pump cartrdge and drive ball bearing are held in drive shaft housing by ball bearing lock ring.remove lock ring with service tool 91-27532A1. on later models (yours)" water pump cartridge is upside down. impeller can be removed without removing water pump cartridge" taken from merc service manual . you need a special tool to get the new impeller in which is up inside driveshaft housing. get the parts manual first
 

turtles11756

Petty Officer 1st Class
Joined
Dec 5, 2007
Messages
260
Re: 1961 Mercury 100 (9.8)

the picture you show of your motor is listed in the service manual under transmission type engine which is different than the instructions i gave .your impeller is located in propshaft housing . if you want me to go thru it let me know.
 

Reg312

Petty Officer 2nd Class
Joined
Jul 12, 2009
Messages
139
Re: 1961 Mercury 100 (9.8)

Thats kind what I thought. Thanks
 

gstraber

Recruit
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Apr 19, 2011
Messages
2
Re: 1961 Mercury 100 (9.8)

I have a 61 Merc 100. It runs great but also needs a impeller. Do you have any details as to how to access the impeller in the prop-shaft housing?

Thanks, Gary
 
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