Simple Aisan Carburetor Question..anyone? (1 Viewer)

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I'm rebuilding my aisan carb on my '87 fj60 and I noticed the needle seat in the rebuild kit doesn't have holes like the original. Should I use the old seat and new needle or would the new seat without the holes be okay. Not sure what the holes are even for. Any help would be greatly appreciated!

Thanks,
Isaac
 
Since the Toyota needle valve is no longer available, install that needle valve if it fits and see what happens. No harm trying it.
 
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these holes are what I'm talking about. I just wanted to prevent having to take the top of the carburetor off if the new one doesn't function properly. Still has all the smog crap installed.
 
@OSS what do the holes in the needle valve do? Do you happen to know? Wondering if this is why I have a consistent high idle after rebuild?
 
The carb I have dissembled is a solid seat and the rebuild kit I have for it is solid too. I didn’t think to open up my spare stock carb... I would guess it has something to do w/ lessening pressure. Marc @mwebfj60 do you know?
 
I just rebuilt a carb recently and noticed that difference too. I’ve heard it runs well. Must not make a difference? I used a Hygrade Carb Kit.

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Perhaps I should take out the word "simple" from the title lol. I agree it's probably pressure related. I was having issues with the fuel bowl filling up and on the rare occasions that it does the fuel level would be right in the middle of the sight glass but drain out completely if left running. I don't think my fuel bowl issue is directly related to this but just wanted to make sure I was using the right piece for my puzzle. I appreciate the help with trying to figure this out.
 
My best guess as to function is that the holes allow gas to flow out of them when the float goes down and the needle is released from its seat...maybe a little less turbulence for the flow coming in? I use the new set just so they are matched. These look to be the same size, I have a couple sets that are different lengths.
 
I have a couple NOS Toyota kits for the 60 carb and they both have the holes in the seat. The aftermarket kits do have that extra machining. mwebfj60s guestamation above seems reasonable, but ultimately, it probably does not make much difference.

I'd use the new one.
 
Awesome, I guess ill go with the new one and as OSS stated "No harm in trying it". If it doesn't work then hey.. what's another week waiting for more parts to arrive :bounce: Thanks guys! :beer:
 
Awesome, I guess ill go with the new one and as OSS stated "No harm in trying it". If it doesn't work then hey.. what's another week waiting for more parts to arrive :bounce: Thanks guys! :beer:
Digging this thread back up- @Mudh8U did you have to revert back to the seat with holes? I’m at this point in the assembly process and wondering if I go “new without holes” or the original with holes. I can’t find a consensus one way or another.
 
I ran into this same issue. I think some fuel can flow around the needle as it opens but even more can flow from those holes - the bigger holes are better. I thought using the one with the big holes would solve my problems. I still had trouble with fuel getting into the bowl and it was the old fuel pickup/suction tube in the gas tank being clogged with rust!

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Digging this thread back up- @Mudh8U did you have to revert back to the seat with holes? I’m at this point in the assembly process and wondering if I go “new without holes” or the original with holes. I can’t find a consensus one way or another.

My guess is those holes are there to increase the flow into the float bowl, so fuel doesn't have to push its way past the needle, only.

The NAPCO kits have the needle/seat with the small holes, as above, as well as the screen strainer. The kits are only available on ebay, from overseas, usually Thailand.

The various other domestically available kits Keyster and SMP and their rebrands all have a Needle/seat without holes. Does it make a difference? If your fuel level stays in the middle of the sight-glass, then probably not. But I do like the small strainer on the end of the seat to capture any dirt that manages to sneak by the fuel filter. More than one 2F carb has been left disabled by a speck of schmutz.
 
My guess is those holes are there to increase the flow into the float bowl, so fuel doesn't have to push its way past the needle, only.

The NAPCO kits have the needle/seat with the small holes, as above, as well as the screen strainer. The kits are only available on ebay, from overseas, usually Thailand.

The various other domestically available kits Keyster and SMP and their rebrands all have a Needle/seat without holes. Does it make a difference? If your fuel level stays in the middle of the sight-glass, then probably not. But I do like the small strainer on the end of the seat to capture any dirt that manages to sneak by the fuel filter. More than one 2F carb has been left disabled by a speck of schmutz.
I got stuck on a steep hill climb this summer. The fuel pump was supplying just enough fuel to keep me idling, but if I put my foot on the accelerator at all it would bog and try die. Now I know all carbs will be susceptible to fuel issues when they're topsy turvy, but I wonder if having the original larger holes would have helped in that situation. And to be honest, I don't even know what's in my carb. I had it rebuilt a while back, but didn't do the work myself.

This thread has me thinkin'...
 
but I wonder if having the original larger holes would have helped in that situation.
The original stock FJ60 carburetor and fuel pump will supply ample fuel to the engine on any slope that the vehicle could conceivably climb. 45° easily. (But vehicle won’t climb 45° due to inadequate traction)
 
I got stuck on a steep hill climb this summer. The fuel pump was supplying just enough fuel to keep me idling, but if I put my foot on the accelerator at all it would bog and try die. Now I know all carbs will be susceptible to fuel issues when they're topsy turvy, but I wonder if having the original larger holes would have helped in that situation. And to be honest, I don't even know what's in my carb. I had it rebuilt a while back, but didn't do the work myself.

This thread has me thinkin'...

I doubt it would cause fuel starvation at low RPM (with the hole-less seat), but possibly at high RPM of highway speeds. Again, if you notice fuel isn't staying in the middle of the sight-glass, that's your answer.
 
In order to avoid having to disassemble the carb no more than I have to, I’m gonna opt to clean up and reinstall the seat that I took out…there shouldn’t be any harm in that I suppose.
 

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