1965 johnson 40 hp won't charge

Paul Moir

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Re: 1965 johnson 40 hp won't charge

Thanks for the great test Joe. I've got this one bookmarked now. :) <br />I only test these older gearcases with around 5psi of pressure - it sounds to me like you're holding pressure just fine. It's possible it's failing on vaccum though - just unlikely. Due to the gearcases only having single lipped seals, they normally don't hold much vaccuum.<br />The simple fix for seal worn shafts is a thing called a 'speedi-sleeve' manufactured by Chicago Rawhide and sold by bearing/seal parts houses. They're thin stainless sleeves that fit over the shaft in the worn area, increasing the diameter there only slightly. Just about any machine shop can install one for you, but you need to remove the shaft first.
 

dafox99

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Re: 1965 johnson 40 hp won't charge

thanks Joe and Paul!<br /><br />just checked lower unit .. 15 psi all day.<br /><br />One quick question on the lower unit ... they develop vacuum? I guess that makes sense in that they would suck water instead of spewing oil. Just wondering what is happening to create a vacuum in there?<br /><br />Thanks again.
 

Paul Moir

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Re: 1965 johnson 40 hp won't charge

Well, they really have to leak to develop a vaccum. Or get filled on a warm day then put into cold water. Just the little bit of air trapped in it contracts. Not exactly rocket science, and not really a big deal on smaller outboards.<br /><br />On modern lower units they use two seals on the prop and driveshaft. Oil seals really work only in one direction. So the 'point' one seal out (to keep the water out) and one seal in (to keep the oil in). These older ones just have the seal pointing in.
 

dafox99

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Re: 1965 johnson 40 hp won't charge

Ahh .. thanks. Makes sense.
 

dafox99

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Re: 1965 johnson 40 hp won't charge

OK .. I briefly jumped "bat" to "field" on the regulator. Ammeter pegged negative. Haven't taken boat out yet. Oh .. also touched field to gnd (nothing).<br /><br />Now for the really dumb question. I found a little aluminum plate that says, "keep hands out". I would guess it goes somewhere in the front in front of the menacing flywheel, but can't find a bolt pattern to accomodate this. It looks like one side goes on the starter bracket (I have an empty threaded hole there), but can't see where the other side would attach. Anyone know?<br /><br />thanks again.
 

Paul Moir

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Re: 1965 johnson 40 hp won't charge

The generator bracket should have a "hook" cast into it. A longish screw goes through the "hook" and into the threaded hole in the other end of the plate.
 

itstippy

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Jul 17, 2003
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Re: 1965 johnson 40 hp won't charge

Thank you Paul for the "two seals" tip! The seal kit for my 1967 18HP can with two thinner driveshaft seals instead of one thicker one. I stacked the two thin ones one atop the other so things would fit right. It worked well because the two seals rubbed in slightly different places on the driveshaft than the old single seal. It's bugged me ever since why the kit came with two. Now I know.<br /><br />Sorry to interrupt this great thread. It is bookmarked!
 

dafox99

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Re: 1965 johnson 40 hp won't charge

BTW,<br /><br />The ammeter was not registering a charge for about 5 minutes and I figured the regulator was shot. Suddenly, it started charging and has been working ever since! thanks again.
 
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