Duel line connector O rings replaced with Sierra O rings, too big??

[thegipper]

I am new here so first and foremost, hello!

So I have two older 1950's evinrudes with the duel line connectors, one of them developed a leak because of faulty O-rings.

I used a small pick to carefully pull out the old O rings on one of the connectors which came out pretty easy because they were falling apart. I ordered new orings from marine engine which are the sierra brand replacement ones.

When I went to install them yesterday I first noticed that they seem rather big for the hole size. Since they said it was the correct part (and I matched it against what they actually sent me) I went forward with installing them. I squeezed the o ring together and pushed it down into the hole of the connector and using the same pick, pushing it back into its place (grove).

Here is where the problem is. The first thing i noticed was the O ring is too large for the "grove" that it rests in. Because of this, the brass plunger doesn't sit flush against the O ring because the O ring isn't flat in the connector, it's slightly bunched up because it is too large. The other problem is because the ID of the O ring is smaller than the original, it is nearly impossible to push the connector onto the motor. I was able to push it on the motor and when it is connected, everything works fine because it does create a good seal (because it is so small). The problem is, when you take it off, gas leaks out everywhere because the brass plunger isn't sealing against the O ring properly.

My question is, are the sierra replacement O rings too big even though they say they are the correct replacement? I thought I saw on one of these forums awhile back that someone complained about the same thing. Anyone know where I can get original (or at least the correct size O ring) replacements?

I also saw that someone sells jigs for taking these cast connectors apart. I do have an arbor press but don't have the jig, has anyone come up with a homemade way to take these apart?

Thanks for the help guys!

 

[F_R]

It is a fairly well-known fact that the Sierra ones are too big, yet they continue to sell them. If you want to get the correct ones, you have to get genuine OEM parts from a dealer, or somebody selling genuine Evinrude parts. An acceptable substitute is -107 Buna-N O-rings from a supplier such as McMaster.

I happen to be the guy that makes that tool. But selling here isn't allowed and my PM box here doesn't work.

 

[thegipper]

It is a fairly well-known fact that the Sierra ones are too big, yet they continue to sell them. If you want to get the correct ones, you have to get genuine OEM parts from a dealer, or somebody selling genuine Evinrude parts. An acceptable substitute is -107 Buna-N O-rings from a supplier such as McMaster.

I happen to be the guy that makes that tool. But selling here isn't allowed and my PM box here doesn't work.

Wow, thanks so much for the quick response.

I found these which say they are OMC replacements, I'm assuming this is what I need?

http://www.marinepartssource.com/newdetails.asp?pnumber=OMC301824&mfg=OMC&desc=O-ring&mfgno=301824

 

[cajuncook1]

You may be able to find the 107 Buna-N orings at a local hardware store for much cheaper and convenience. Call them up and they can look to see if it is in stock.

 

[thegipper]

You may be able to find the 107 Buna-N orings at a local hardware store for much cheaper and convenience. Call them up and they can look to see if it is in stock.

Just called up my local boat dealer in town and sure enough he has the original OMC ones in stock. I would have never thought!

Going to stop by after work later and get a few ($2.00).

Thanks guys

 

[Steve A W]

thegipper
You have a PM

 

[thegipper]

Hey guys just want to give everyone an update. So I picked up a couple of the OMC O rings from my local parts dealer, I surprised that he had them.

I pulled out the Sierra ones and compared them, they are absolutely too big and shouldn't even be sold as replacements! I put in the new OMC ones but unfortunately they still didn't seal. At this point I thought that either the springs are weak and or the brass plunger is messed up. After looking at the connector some more, I decided it needed to come apart. I took an extra 2mm allen wrench I had and cut off the short bend of it so I had a strong straight piece to push the brass fittings out of the connector.

I pulled out my arbor press and the base plate has a slot cut in it that was just smaller than the outside profile of the connector but large enough for the round brass fitting to come out. I dropped the piece of allen wrench down the fuel line fitting first and with only a little bit of pressure, it came right out! Did the same for the air side with the same results. Now I'm sure having a die makes it easier but if you have any kind of press (maybe could even be tapped out if it was in a vice?) these things come apart with ease.

The plunger on the air side looked perfect but on the fuel side (where the biggest leak was) it was a little marred up from when I originally pulled out the 50 year old O rings. I took some 600 grit paper and chucked the square base of the brass plunger in my cordless drill. I slowly rotated plunger while removing the scratches with the sand paper. A couple minutes later it was perfectly smooth. I found some similar springs that I had laying around but they were about 3/8" shorter but MUCH stronger. I dropped one in there and put the plunger on it to see if it was still high enough to be pushed into where the O rings sit, it did.

I cleaned everything out real nice and put it all back together using the new springs and voila, perfectly sealed connector. I tested it on my Mint 58 5.5hp just to make sure it worked and it was perfect. Anyways, just thought I would share how I fixed mine for anyone else that runs into the same problem. DO NOT BUY THE SIERRA O Rings

http://vid1127.photobucket.com/album...psw3x6r8in.mp4

 

[Sirrobin53]

GREAT motor. PERFECT Love those old motors, (see avitar)

 

[HighTrim]

If you use the 107 o rings, they are a touch too narrow. I double stack them for a good seal.

I have Franks jig. Makes the job pretty easy!