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Spifire 1500 Carb teardown question

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JodyFKerr

JodyFKerr

Jedi Knight
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Hey Folks,

I was tearing down the Carburetor on mum's Spifire last night and I got to this point. Now, I'll admit I don't have the specs on this specific carburetor, but I've rebuilt plenty in the past.

033_web.jpg


You'll note the red arrow in the photo. This center shaft really looks like it should be removable. I attempted this, but didn't want to force/break the part.

Can someone confirm that this should be removable? If it doesn't come out I'm not certain how to remove the needle.

Thanks!
Jody
 
The center shaft isn't removable. There should be a set screw at the bottom that holds the needle in place. Remove the set screw and then you most likely have to use an allen wrench down the tube to unscrew the needle.
 
If you are referring to the part with the set screw that holds the needle it is removable. You have to force it out. It is retained by a externally fingered push washer. There is an o-ring around the piece that retains the damper oil in the shaft. If you search there are existing threads describing the process in more detail.
 
Thanks for the help guys. Got the carb all rebuilt.

Went to put it on Mum's Spitfire tonight and get the car running and ran into the following issue. The starts and idles, but has no acceleration power, I drove it around the block and barely got it back to the garage. I also noted that the catalytic converter was cherry red when I got the bonnet opened again.

There's a couple possible items that it could be, but I'm hoping the collective wisdom will point me in the right direction.

Jody
 
Sounds like the mixture is off Jody, my guess is too rich from the catatlic converter being that hot. I'd get other opinions...
 
Depending upon your exact carb you should have an ability to control the mixture by inserting a long allen wrench into the top of the air chamber, down into the tube you have the red arrow pointing at. Not every ZS carb will allow this.

Here is a good write up on your Spitfire;

https://www.triumphspitfire.com/Carb.html

Keep us posted.
 
JodyFKerr said:
Thanks for the help guys. Got the carb all rebuilt.

Went to put it on Mum's Spitfire tonight and get the car running and ran into the following issue. The starts and idles, but has no acceleration power, I drove it around the block and barely got it back to the garage. I also noted that the catalytic converter was cherry red when I got the bonnet opened again.

There's a couple possible items that it could be, but I'm hoping the collective wisdom will point me in the right direction.

Jody
Click to expand...
Sounds an awful lot like not having the diaphram/air valve oriented properly.
There are 2 index tabs on the diaphram that insure that the air valve is oriented properly.
The tabs must find their home in the slots on top of the air valve and the carb body.
You really do need to study this, because ZS carbs are obviously unlike any other carbs you've rebuilt or adjusted.
https://www.buckeyetriumphs.org/technical/Carbs/CarbsI/CarbsI.htm
 
Poolboy - wouldn't the diaphragm not being properly installed typically result in a lean not rich mixture? I may be getting thrown off by the cat here, which could be unrelated...
 
Hey all,

So I started the latest round with the carburetor this evening. Headed over to Mum's with a spare carb, tools, and determination. Got down there, did some mixing and matching of parts, tweaked a bunch of settings on the carb, and got her running properly!

Made it around the block just fine, then drove Mum around the block. All excited we got ready to head off to the DMV to get the emissions test. As I wen to pull the car out to go to Emissions it just died. Dead as a doornail!

WE pushed it back into the garage, and I set back to work fiddling with the carb and timing. I'd get it running, then hop in to drive it and it would die. Finally, I noticed as I was watching the carb and mum was hitting the accelerator pedal that there wasn't any fuel coming into the carb. Disconnected the fuel line, turned it over a few times, and no gasoline. Now I'd already replaced the fuel filter and the fuel pump earlier, and figured that there was something in the lines or tank that was plugging the fuel system.

Got down to trace my way back through the entire system, and lo and behold, what do I find? A *second* fuel filter installed in a hard to see location. And the best part, this fuel filter was installed *backwards*!

Slapped a new fuel filter in place and in the correct orientation.....
Sucked a bunch of the air out of the fuel line to prime it with gasoline....
Got in, turned the key, waited a moment and VROOOOOM~!

Decided to see if it had power, so threw it into first, stomped on the accelerator and left rubber in the garage. :smile:

So tomorrow, it's time to retune everything and take it through emissions!

Thanks for all the help!
Jody
 
tdskip said:
Poolboy - wouldn't the diaphragm not being properly installed typically result in a lean not rich mixture? I may be getting thrown off by the cat here, which could be unrelated...
Click to expand...
A lot depends on how the air valve ends up. I've seen them end up as much as 180* off. If the air holes in the air valve aren't exposed to the manifold vacuum the air valve won't rise.
The manifold vacuum has to "pass thru" the holes, into the hollow air valve, up to the top of the diaphram to suck the air valve upward.
 
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