1978 4hp Johnson water pump

theonn

Cadet
Joined
Jun 17, 2009
Messages
7
I need to replace water pump the bolt heads are rounded is there a tool to remove I thought about cutting the heads off went to johnson site one bolt is $28.00 the other is $9.00 anyone know if bolt & threads are a standard size
 

Rick.

Captain
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Jul 30, 2006
Messages
3,740
Re: 1978 4hp Johnson water pump

They are standard thread and size. Any hardware would likely have them for much cheaper. I'm pretty sure they are stainless steel though. As far as getting them out I guess I would try vice grips or channel lock pliers. Something has to work. Best of luck. Rick.
 

mafhuntfish

Seaman
Joined
Mar 20, 2009
Messages
71
Re: 1978 4hp Johnson water pump

I agree with Rick - but those bolts were rounded off for a reason - severely stuck. I would soak them several times for a few days with PB Blaster before I tried to remove them - it's worked for me in the past
 

bankerjohn

Chief Petty Officer
Joined
Mar 21, 2008
Messages
444
Re: 1978 4hp Johnson water pump

I assume you're talking about the bolts that hold the gearcase on (not the ones that hold the water pump on).

I checked a couple sites for those 2 bolts ... and found these prices at www.shop2.evinrude.com:

0302030 - $2.25 (front)
0313332 - $3.06 (rear)

But I also found some different part numbers at another site, with much higher prices:

0315221 - $17.90 (front)
0315220 [0330666] - $7.06 (rear)

I can't fathom how a bolt could possibly be worth $17, or $7 for that matter.

Good luck on getting the old ones out!
 

theonn

Cadet
Joined
Jun 17, 2009
Messages
7
Re: 1978 4hp Johnson water pump

Thanks for your reply Bankerjohn, you are correct the bolts are the long gear case bolts. Is pb blaster available at auto part stores? The bolt heads are rusted so not SS.:D Theonn
 

mafhuntfish

Seaman
Joined
Mar 20, 2009
Messages
71
Re: 1978 4hp Johnson water pump

PB Blaster is available at most auto parts, most hardware stores, Walmart, K Mart, ect
 

bankerjohn

Chief Petty Officer
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Mar 21, 2008
Messages
444
Re: 1978 4hp Johnson water pump

The bolt heads are rusted so not SS. Theonn

They should be stainless!

Sounds like maybe a previous owner replaced the original bolts with non-stainless ones. If that's the case, hopefully the threads were the correct size ... if not you may have to put in some helicoils once you get the old ones out.
 

Vic.S

Rear Admiral
Joined
May 4, 2004
Messages
4,719
Re: 1978 4hp Johnson water pump

Also try to get some heat around them. Thats the way to free bolts from aluminium alloys. Boiling water to start with, cautious use of a hot air gun if that fails.
Propane torch .. last resort.
 

theonn

Cadet
Joined
Jun 17, 2009
Messages
7
Re: 1978 4hp Johnson water pump

Got it appart. Had to cut off the heads and drill the bolts out, then cut bolts inside the extention with a home made drimel. Turns out the water passage under the power head was cloged. Waiting for parts now. Thanks guys for your help.
 
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