Tell Tale Fitting

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BigTerp

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Noticed water coming out of the bottom of my cowling yesterday. When I popped the hood I found my tell tale fitting "cap" had cracked and it was shooting water into the cowling. Apparently my motor (1994 Johnson 50/35) has 2 tell tale fittings. The main one with the water hose is functioning properly and has a nice strong stream of water. But this one, on the side of the crankcase water passage cover, was apparently plugged with a cap at some point. First off, I didn't realize there was another fitting. Secondly, why is it capped? Third, where can I get a new cap for it or how should I go about plugging it back up? Yesterday I just used some electrical tape I keep on board to tape the old cap on as good as I could to prevent water from getting all inside the engine.

Here is the piece in question.
IMG_20150614_113338_zpszm7bvxnj.jpg


IMG_20150614_113352_zps15ndkckp.jpg


IMG_20150614_180511_zpsra37oz1r.jpg
 
Could also be a fitting to attach to an in-dash pressure gauge. I'd replace the fitting with a plastic plug. The threads are 1/8" NPT. You can get a fitting online, you might be able to find one at a hardware store.

Definitely go with the plastic to prevent galvanic corrosion.

Good luck!
 
kofkorn said:
Could also be a fitting to attach to an in-dash pressure gauge. I'd replace the fitting with a plastic plug. The threads are 1/8" NPT. You can get a fitting online, you might be able to find one at a hardware store.

Definitely go with the plastic to prevent galvanic corrosion.

Good luck!

Thanks!!

That should be 3/8" though, right?

Just one of these? https://www.usplastic.com/catalog/item.aspx?sku=64717&gclid=CLO43ZW7qLYCFac7MgodfkoAQA
 
take it to the local hardware store - they usually have a board with all the different fitting sizes and thread pitches for you to thread your old one into and match up so you know what you need as a replacement...much safer than trying to guess @ home.
 
Picked this up at Lowe's today (they didn't have any plastic ones) and it doesn't fit. Looks the exact same size and thread size of the old fitting. But it's really hard to thread into the hole. Afraid if I force it anymore than I already have I'll end up cross threading the crap out of the the hole. Any ideas?
IMG_20150615_192814_zpsgvyo62en.jpg
 
Skiffing said:
brass on aluminum?

Yes. Just a temporary fix until I can get a proper plastic plug or figure something else out so I can get back on the water. 1/8" - 27 npt plastic plugs seem hard to find.

Need to figure something out. I'll never use that plug/port so I'm not opposed to some sort of permanent fix as well.
 
It looks like the right one. The plug should turn in easily for about one or two turns and then tighten up. It's a tapered thread, so it doesn't go all the way in. If you can't get a half turn by hand, don't force it in. If you can get a full turn, then tighten it up and you're good to go. Normally you use teflon tape or pipe dope to lubricate the threads while tightening, but that could potentially leave something to get stuck in your cooling channels, so I'd stay away from the tape for now.

I agree with the comment above that you don't want to leave a brass plug in for long. It will definitely eat away at the aluminum around it before too long. A month or two won't be a problem though.

Another temporary way, if you can't get the brass plug in is to take a very short piece of tubing that will fit over the original barb. Melt one end and while it's hot, clamp it with a pair of pliers to seal the end off. then you can put the other end over the barb and you've made a VERY temporary cap. Make sure to clamp or zip tie the tubing to the barb.

Good luck!
 
Thanks.

That seems to make sense. The brass plug would start sort of easy, but then quickly get really hard to turn in. Definitely couldn't easily get a full turn though. I used a tiny crescent wrench to work it in, but didn't want to torque it down to much for fear of breaking something.

Will a plastic plug go in easier/further than the brass? Is standard nylon OK? I can find nylon, polypropylene and Kynar ones online. $10 just to ship one of those tiny things though :shock:

Any idea what I.D. tube I would need to fit over the original barb?

Here is what was on it before. Looks like just a sort of rubber cap. It obviously worked though, but finally cracked and deteriorated. If I could just get another one of these I would be good to go.
IMG_20150615_193450_zpsiumyvck3.jpg
 
Any material plastic plug will be fine. The plastic will go in easier because it has give to it. I wouldn't be surprised if they manufacture that hole smaller than normal pipe standards because of that reason.

it looks like 1/4" tubing will fit, maybe 3/16". You'll need to use some type of plastic tubing though, not rubber. Rubber tubing won't melt, just burn.

Good luck!
 
I'd stick to the black nylon for the temperature range rating - your motor will be at its warmest right after you shut it down and there is no longer water circulating through it. The nylon is rated high enough that the motor shouldn't come anywhere near it's max rating, whereas the next one being rated for 226 it is entirely possible for it to warm to that point.
 
Ok, you made me curious so I had to go in the garage and look at my 40 hp Evinrude. It actually has a metal plug that takes an allen wrench. It's painted along with the block so I can't tell what the material is.
 

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