Disassemble carb 33hp Evinrude

[ward cleaver]

I am working on the carb on my 1970 33hp Evinrude. Problem is the low speed needle valve will not come out. I have put the knob back on and screwed it down but when I turn it, the knob spins but does not turn the needle valve. Trying wd-40 and even some old liquid wrench i'm sure my dad bought 40 years ago. Anyway, how do I back out this valve without destroying anything?

 

[rickryder]

Re: Disassemble carb 33hp Evinrude

atf and acetone mixture make a great penetrating oil

And Ward don't be to hard on the beaver tonight!
Just had to say that!

 

[ward cleaver]

Re: Disassemble carb 33hp Evinrude

atf as in automatic transmission fluid?

Theodore is still a handful.

 

[rickryder]

Re: Disassemble carb 33hp Evinrude

yup

 

[F_R]

Re: Disassemble carb 33hp Evinrude

So you are saying the needle won't even rotate? That's mighty unusual. Is the carb highly corroded or something?

Well anyhow, the needle screws into a threaded bushing. The bushing is held in by the packing nut and packings. That means by removing the packing nut, the needle should pull out, bushing and all. If you can't pull it out by hand, try clamping the needle shaft in a vise, then gently tap the carburetor body away from it with a plastic mallet or something.

Once it is out, you can examine it and figure out why it wouldn't turn.

Correct procedure for reinstalling it is important. Slide the packing nut onto the needle, along with new packings, and the bushing, turning it into the bushing a few turns. Then slide the whole assembly into the hole. Snug the packing nut down enough to keep the bushing from spinning. Now screw the needle all the way in till it GENTLY seats, then back it out 1-1/2 turns. After final adjustment on the water, tighten the packing nut enough so it stays put.

 

[ward cleaver]

Re: Disassemble carb 33hp Evinrude

This motor hasn't run in a looooong time.

Don't have any acetone. How about carb cleaner?

Well, if the bushing is suppose to come out along with the needle, then I have a problem with the high speed side since all that came out was the needle. How about I disassemble the rest and soak that whole part in carb cleaner?

 

[AlTn]

Re: Disassemble carb 33hp Evinrude

looking at the carb diagram at marineengine.com...#37 needle packing x2...#38 washer x2...#36 x1 needle bushing...should be in the idle mixture needle passage along with the needle as it won't come out?..I'd give F_R's suggestion a try first. Have you removed the core plug for the idle holes < on top of the carb at the end of the idle mixture passage >? You might gain a little lubrication by spraying carb cleaner on that end of the needle passage/bushing. I don't know from experience whether soaking in carb cleaner will degrade the plastic bushing and washers. I know the packing will be.

 

[ward cleaver]

Re: Disassemble carb 33hp Evinrude

Thanks for all the advice.

Back to the needle that came out ok - I picked the packing out of the passage but the bushing still would not come out. So I found a screw that mated with the bushing and grabbed the screw with my pliers and yanked the bushing out. The bushing is metal. So I assume the other one is too. Didn't see any washers.

The needle that is still stuck did not respond to soaking in wd-40 overnite. I tried to grab the needle with pliers and I'm afraid I can't squeeze hard enough to hold it without damaging the needle. I suspect it is the packing that is keeping the needle in there because I see a stripe of packing on the needle that did come out. So I'll try soaking in carb cleaner. BTW this needle will not even turn.

The interior of the carb is heavily coated with varnish.

 

[AlTn]

Re: Disassemble carb 33hp Evinrude

are you referring to the lower needle in the carb..the one in the lower casting?...you removed a metal bushing from this passage?..I dunno..maybe there's a seat in the passage that comes out ,but I don't see one in the carb diagrams at marineengine.com

 

[F_R]

Re: Disassemble carb 33hp Evinrude

The original question referred to the low speed needle, and that is the wone I wrote about---with a bushing.

Now we seem to be talking about the high speed needle all of a sudden?? There is no bushing on that one, it just unscrews. Period.

 

[ward cleaver]

Re: Disassemble carb 33hp Evinrude

Sorry for any confusion. I removed the low speed needle valve, packing and bushing.

The needle that is stuck is the high speed needle which I assumed had a bushing like the other one. But now I can see in the drawing I have that it doesn't have a bushing -- just packing and a nut. The nut came off fine. But the needle won't budge. This is the needle that is on the float chamber casting. Now that I can see better inside the float chamber, I can see a substantial amount of black goo (which I assume is varnish) on the end of the needle inside the float chamber. Most of the goo has been removed after soaking in carb cleaner for 3 or 4 hours. What's left of the goo may be keeping the needle from turning. Should I let it soak overnite and see if the goo is gone and the needle turns so I can get it out?

 

[F_R]

Re: Disassemble carb 33hp Evinrude

Yes, it has to be squeeky clean anyway.

 

[ward cleaver]

Re: Disassemble carb 33hp Evinrude

After a lot of soaking in carb cleaner and some scraping, I finally got all the goo out. The needle came out pretty easily after that.

Thanks for all the suggestions.