I have what I believe is a CA early 76' model carb that I have started to rebuild. I've been utilizing Pinhead's very helpful rebuild video. When I got the top cover off I realized the plunger for the accelerator pump was jammed in flush with the carb body (see pics below and screenshot from Pinhead's video of how it is supposed to look). It appears someone previously tried to get it out given the etching around it. Any thoughts on dislodging it without tearing up the plunger and or body? Thanks!
Carb rebuild question
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thebigredrocker
SILVER Star
That's called the stopper. The accelerator plunger is in the big hole.
I had a heck of a time removing one also. I used compressed air. I had to block off the main jet holes and power jet hole to build enough pressure. I used m5 screws for the main jet holes and a m6 screw with a small allen head in the power jet hole. I used a rubber tipped air nozzle to pressurize the stopper passage via the tiny brass orafice. You'll need to plug the big accelerator pump chamber. I also blew air the opposite direction, insert air nozzle in Acc Pump chamber. Wrap something around your air nozzle(chunk of bicycle tube) to create a seal and hold your finger over the small brass tube that delivers fuel from stopper chamber. You could also CAREFULLY heat the stopper and add drops of oil afterwards.
The other thing I've seen done to remove a stopper is drill the center to spin it and thus break it free. I'd avoid this if possible. Stoppers aren't easy come by.
Far right is an OEM stopper that was drilled. It was still usable. Left is one I made from a rivet for a carb that had a missing stopper.
I had a heck of a time removing one also. I used compressed air. I had to block off the main jet holes and power jet hole to build enough pressure. I used m5 screws for the main jet holes and a m6 screw with a small allen head in the power jet hole. I used a rubber tipped air nozzle to pressurize the stopper passage via the tiny brass orafice. You'll need to plug the big accelerator pump chamber. I also blew air the opposite direction, insert air nozzle in Acc Pump chamber. Wrap something around your air nozzle(chunk of bicycle tube) to create a seal and hold your finger over the small brass tube that delivers fuel from stopper chamber. You could also CAREFULLY heat the stopper and add drops of oil afterwards.
The other thing I've seen done to remove a stopper is drill the center to spin it and thus break it free. I'd avoid this if possible. Stoppers aren't easy come by.
Far right is an OEM stopper that was drilled. It was still usable. Left is one I made from a rivet for a carb that had a missing stopper.
thebigredrocker
SILVER Star
Make sure you write down your jet sizes
- Thread starter
- #5
Thanks Big Red! This is my first rebuild--what exactly does the stopper do? It seems like with the top cover on the stopper can't go anywhere anyway.
- Thread starter
- #6
Jetlander - that definitely seems like a quick easy fix. I'll give that a try first. I was just worried since it looked like the PO etched the crap out of the sides trying to get it out. Thanks for the advice!
thebigredrocker
SILVER Star
Here's my understanding.
It limits brass weight travel. In conjuction with a rubber gasket(o-ring) on top, it also seals in the discharge chamber.
When you pump your gas pedal, you are basically pushing the AP plunger down which forces fuel into the chamber the stopper resides in or AP discharge chamber. The fuel then exits via a tiny chunk of brass tube that is inserted just below the top plane of the stopper lid. The brass is angled so that it squirts fuel into air being sucked in to your combustion chambers. When that big *ss squirt of fuel/air is compressed by a piston and kissed with spark, you'll have power to climb mountains.
When you let off the gas pedal, the AP plunger is pulled back up and fuel is pulled in for the next big squirt. Underneath the stopper you'll find a brass weight and steel bb that help to keep fuel primed in the AP discharge chamber("stopper chamber") as the AP plunger rises and draws fuel.
-Tip from carb guru FJ40Jim reguarding the two steel bb's found in your rebuild kit "repeat after me, small ball- big hole, big ball- small hole"
If you have a crappy AP plunger stroke you will only get a weak dribble of fuel squirt joining the air being sucked into the combustion chambers. This will cause your engine to hesitate when given to foot command to "go". IOW lack of power. Quote from California carb guru 65swb45
It limits brass weight travel. In conjuction with a rubber gasket(o-ring) on top, it also seals in the discharge chamber.
When you pump your gas pedal, you are basically pushing the AP plunger down which forces fuel into the chamber the stopper resides in or AP discharge chamber. The fuel then exits via a tiny chunk of brass tube that is inserted just below the top plane of the stopper lid. The brass is angled so that it squirts fuel into air being sucked in to your combustion chambers. When that big *ss squirt of fuel/air is compressed by a piston and kissed with spark, you'll have power to climb mountains.
When you let off the gas pedal, the AP plunger is pulled back up and fuel is pulled in for the next big squirt. Underneath the stopper you'll find a brass weight and steel bb that help to keep fuel primed in the AP discharge chamber("stopper chamber") as the AP plunger rises and draws fuel.
-Tip from carb guru FJ40Jim reguarding the two steel bb's found in your rebuild kit "repeat after me, small ball- big hole, big ball- small hole"
If you have a crappy AP plunger stroke you will only get a weak dribble of fuel squirt joining the air being sucked into the combustion chambers. This will cause your engine to hesitate when given to foot command to "go". IOW lack of power. Quote from California carb guru 65swb45
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- Thread starter
- #8
Thank you for the explanation--that all makes sense now! I'll keep you updated on the stopper extraction. Hopefully she comes out without too much of a fight.
Toyota calls it a 'discharge weight stopper' ...
A lot of those seem to get staked down by rebuilders, for reasons beyond my pay grade.
I was able to remove by using a very sharp pick to remove the staking and it popped up.
A lot of those seem to get staked down by rebuilders, for reasons beyond my pay grade.
I was able to remove by using a very sharp pick to remove the staking and it popped up.
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- #10
Good to know. I am going to get on it tonight. It is the last thing to get out of the body before it goes in the carb dip. Thanks for the help!
Are you sure the previous owner staked it down or perhaps the "stake" marks are simply the PO's attempt at removing the stopper? They get stuck in there often without being staked.
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- #13
That was miserable, but finally got it out after an hour. Looked like the PO hammered it in there. The stopper was all distorted and there was no spring (I guess that is why it was so hard to make any progress). I'm going to have to carefully try and file down the edges on the stopper opening where it was hammered to get the stopper to fit smoothly. Thanks for everyone's help!
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- #15
Good to know. Btw, your rebuild video was incredibly helpful!
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- #16
Pin_head - do you have any idea what the size on that spring is for the stopper? I called SOR to see if they had one, but no luck there.
You could measure the length using the bowl casting and plug plus the fact that the spring holds the stopper up by about 4 mm. I might have one in my junk box, but I am too tired to dig through it. It is about the length of a ball point pen spring.
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- #18
Thanks. I'll measure and start disassembling some pens!
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- #20
