Broken Needle Valve

[geekomatic]

1979 Johnson Seahorse 2HP. I bought a carb rebuild kit plus a new low speed needle valve,which was really worn out when I bought it.I put it back in to avoid losing it.<br />Upon removing the valve, the actual "needle" part has separated (broken off) from the valve and is resting in the hole.How do I remove this tiny piece of brass in order to replace the entire needle valve?<br />Just above the valve orifice, there appears to be what looks like a "freeze plug" that would give me access to this area in order to push the broken piece out.Am I going in the right direction.How do I remove this plug?I just happen to have a replacement if I can get the old one removed.

 

[Joe Reeves]

Re: Broken Needle Valve

Carefully and gently tap the center of that core plug with a center punch which will shrink the outer diameter of it. You may need to then tap a scribe point thru it to pry it out.<br /><br />Be carefull that you do not insert the scribe too far which might damage the carburetor.

 

[geekomatic]

Re: Broken Needle Valve

Capt. Joe, The plug came out fine with just a little tap of a punch, just like you said. The leftovers of the needle valve are a different story.I cannot remove it regardless of what I try.I've tried heat,pushing it out with a punch,etc.IT's stuck in there very well.There's not a lot of room to work with,as you know.Is it possible to use my Dremel and drill the brass out? I realize there's a bit of a taper involved and I've not figured a way around that yet.Thanks again!

 

[Joe Reeves]

Re: Broken Needle Valve

Unfortunately that hole is critical. Attempting to drill it will result in a weird shaped hole whereas any acurate adjustment will be just about impossible. I've been lucky at times in tapping it out of there with a very sharp pointed scribe, but by the same token there's been a few stuck so bad that a carburetor replacement was required.<br /><br />That's a job/problem that none of us look forward to.

 

[AlexeiVT]

Re: Broken Needle Valve

Just an idea...but maybe try to first seal up those other holes (the one's under the removable plug...or replace it w/ a new one, it should be airtight).<br /><br />To get a sufficient quantity of compressed air at high PSI in through the orifice, try going through the fuel inlet (if you remove the carb bowl, you'll see one tiny hole running up the side...that's where the gas goes up, and eventually up through to the low speed idle area...where the needle is broken off).<br /><br />You just want to seal the other areas where fuel would naturally flow out, so you concentrate the force of the air, just on the needle.<br /><br />Aside from that, perhaps using an inexpensive electric engraver will produce sufficient vibrations to loosen things (a bit of penetrating oil also wouldn't seem to hurt, to get at least a microspic layer of material where it can...it can only help to reduce at least some friction).<br /><br />Lastly...perhaps you've already tried...is there any way to just bend a stiff thin wire at a right angle and precisely poke at this? (the carb on my motor may be different, and thus my suggestions inapplicable...but when the low speed needle is fully seated, you can see it protrude just a tiny bit into that area covered by the plug that was removed)...best of luck.

 

[R.Johnson]

Re: Broken Needle Valve

The hole you have uncovered is called a calibration pocket. At the very front of this pocket, and in line with the needle valve drill a small hole slightly larger than the needle valve hole. Take a small, stiff wire and grind the end flat, not pointed. Use it to drive the broken valve straight out of it's seat. To reseal the drilled hole, peen it shut with soft solder just like the hole's closed shut with a lead shot. This has worked for me.

 

[geekomatic]

Re: Broken Needle Valve

Oh Boy.I tried for hours last night to tap the thing out to no avail.It's in there very well.The compressed air trick is pretty much out of the question for me.The area to work in is so small, I'm not sure what else I can try.I'll give it another try tonight, and if it ends up damaged,then I haven't really lost anything at this point.I'm already looking for a replacement.I'm pretty sure I can get a carb from a higher horsepower motor, but I'm not sure how high I can go.These things are a bit hard to find. <br />Thanks for all the tips!

 

[dblowers]

Re: Broken Needle Valve

This totally worked for me... I tried using a nail from a pin-type nailer, but that would not do the trick,, there was enough room in the tiny hole I drilled so I used a slightly larger nail and it worked after I wiggled it around a few times.

Couple of things I would add to the fix:
Strip the insulation off a piece of wire and push it onto the needle before you try to remove it using this method. When it does remove, it will just come out with the insulation instead of dropping somewhere.

Only sand one side of the nail or wire as to create a wedge that will push the needle out. Don't be afraid to wiggle it forward and back as to push the needle out.

Next issue::: the needle was stuck because the needle was bent... I guess a previous owner forced it in or something... now off to find a new needle