butterfly valve seized and jets gunked

[allymoss]

Hello,

I have a 50hp blueband merc, 2 stroke 4cyl from 1979 I think.

Problem is this, butterfly valve is seized on both carbs. I have tried wd-40 every 30 minutes for a day, no luck. I have heard people put in diesel but wouldn't this take ages! Is heat then wd-40 while its hot and it will suck it in as it cools somehow. Is this a good idea. Obviously I would remove any plastic parts first.

Next problem is this
The jets are quite small obviously and have been sitting a while (years) full of cr*p. Now, I used wd-40 and compressed air at 120psi to get everything out but Im still not sure they are spotless. I am 16 and on a tight budget so buying new ones is not an option unless damaged or necessary. As its brass I don;t want to stick something down them incase I scratch the inside and cause them to not work or am I being over protective?

Also, can anyone tell me what the socket on the front of the 50hp merc 4cyl, 2stroke blueband does? Has one cable coming from the back, mines been cut so I don;t know where it goes to!

Thanks

 

[JMRuth72]

Re: butterfly valve seized and jets gunked

You should be able to go to your local auto supply shop and pick up a 3/4 gallon can of carb cleaner. There is one that is reasonably enviromentally friendly and works pretty good. It also has a basket in it. Follow the directions thoroughly. If that doesn't work get a metal can with a lid big enough to put the parts in and fill it with just enough mineral spirits to cover the parts. It is not enviromentally friendly so you will have to make some calls to find out where to dispose of it, but it works. You may have to let it soak for a day or two, but this is what my gunsmith and I use on our parts and it works good. As for the small jets see if you can pass a pipe cleaner through it with out the wire touching the brass. If it will this usually works really good. If they are smaller than that I am not sure, you will probably have to use your imagination. Just take your time and be patient. I once worked on a motorcycle carb where the jets were so small that I could not find any type of brush that would fit. I ended up using very small drill bits twisting them by hand starting small and working my way up until I got the gunk out then cleaned them with more carb cleaner. Time consuming and tedious but it worked great and the bike ran like a champ once I got it tuned up right. Have no idea on the other part. I am new to this and don't know anything about outboards yet. Good luck, take your time , follow any and all directions and be patient and you should be ok.

 

[Chris1956]

Re: butterfly valve seized and jets gunked

I think you need to soak those carbs in a carb cleaner to get rid of the gunk, and then soak them in gas-oil mix to loosen up the throttle plates. Blow out all the passages after the carb cleaner soak, and then again after the fuel soak.


If worse comes to worse, those "butterflys" likely may be removed from the throttle shaft (2 small screws), and the shaft could be driven out. You will likely destroy the shaft it you do this, so have a used one ready to install.

 

[Yepblaze]

Re: butterfly valve seized and jets gunked

I would think it would depend on what is causing the issues you describe.

If it's just gooey gas/oil/varnish that can be addressed with a can or two of Chemtool B-12 carb spray, a stiff acid brush, compressed air, and a probe or two to resize the orifices. (even still if in real bad shape and you decide to remove welch plugs and such it could be quite involved.

If it's a corrosion issue (for whatever reason) you may be hard pressed to make them "Fully Serviceable"

There was a time, or two way back when, when I used to use Chemdip, but that was a long time ago and the stink still haunts me when I get near areas where it ate through the can, got spilled, or even rinsed off.

Perhaps they have changed the composition of it, but I probably won't go there again. I've managed to save a lot of carbs without going for the magic genie in the can.

 

[allymoss]

Re: butterfly valve seized and jets gunked

ok thanks. I will go get some carb cleaner.

Does anyone know about the socket?

 

[ddennis]

Re: butterfly valve seized and jets gunked

I would not use heat on a carb at all unless a last resort. Soak them in cleaner for a day or two and see if that helps. The "socket" you refer to...post a photo of it! at first guess I would think it is the connector for the boat wiring harness to connect to it..

 

[allymoss]

Re: butterfly valve seized and jets gunked

sorry can't take pics but it looks like a normal 1/4 inch jack socket but can't tell. Single core so must be part of an earth circuit

 

[Yepblaze]

Re: butterfly valve seized and jets gunked

What's a jack socket?

 

[allymoss]

Re: butterfly valve seized and jets gunked

standard socket for headphones or stuff like that. Im not sure it is though, doesn't seem that deep.

Does anyone have any idea what this goes to. Where should I connect the wire that comes out the back of the socket. Its single core. What do I plug in the socket and where should that go to. I wiring diagram would be great!

 

[allymoss]

Re: butterfly valve seized and jets gunked

Also, I thought it was thunderbolt ignition because it says that on the front BUT it has a distributor which I have read is not thunderbolt. Merc 50hp, 4cyl, 2 stroke

 

[jimg984]

Re: butterfly valve seized and jets gunked

If Its An Earth Circuit,,,,,, Splice A Longer Wire To It And Stick The Other End Into The Ground (dirt, Earth) Lol

 

[allymoss]

Re: butterfly valve seized and jets gunked

you know what I mean!! Earth as in the casing of the engine