Weber and Rich Condition

[neverone99]

OK I received the idle jets I ordered and installed a 65 primary idle and 60 secondary idle jet. I was able to get it idling with no smoke! Unfortunately when you rev it in to the primary main jet it still smoked. So I took the top off the carb and the jets inside the fuel bowl at the bottom are both 135. Seems way small...could this have been my issue all along? I have read that the idle circuit does still use the primary jet (I could be way wrong on that).

@splatterdog - you are running a 140 primary main and a 150 secondary main on your 3a. Seems like my problem could very well be that my mains were too small?

[gatemaster]

splatterdog - you are running a 140 primary main and a 150 secondary main on your 3a. Seems like my problem could very well be that my mains were too small?

I am running 140 pri and 150 sec as splatterdog and I am at 7500 feet. I don't know if I went richer if I would get more power. I was trying to maximize power and keep gas mpg at 30+. Having to go that rich on the idle jet means you are probably compensating for too lean main jets.

[gmeddy]

I would really like to know what size jets i should be running, and if i need to replace all the gaskets and seal it up with gasket silicone, see leakiness in last photo.

I think I am running way too rich, the tops of my pistons are all gunked up with sticky looking black, looking in through the spark plug hole i can see this.
and my plugs are the same, all black and sticky gunk on them.




It always smells like fuel when i get out after shutting it down.

I have size 55 pri. idle jet, size 50 secondary idle jet.
I dont know what size the other main jets and air jets are, but just looking down from above when the air filter is taken off i can see two jets without taking the lid off, these are side by side and they are size 165 and 150.

as you can see here... to the left of the throttle intakes you can look down and see two brass jets, are they air jets??


I have to screw out the idle screw around 4 turns to get it to run smooth.
I live around sea level.

the whole weber is quite dirty with oily residue, all around the outside around the gasket seals areas, and looking down the throat, she's quite greasy looking too.



now and then she pop's when starting up, and now and then runs on badly when shutting down the engine. Although not so much when i've got the idle screw turned out a bit more.

This thread has been very informative so far, but i'm not clear from anyones comments yet just what the best jetting is for a 3A engine at sea-level in warm humid conditions.

thanks everyone so much for all these great threads so far.

[dlb]

gmeddy, your pics aren't showing up for me in this thread or the other one you just posted in.

[deejay1272]

The numbers designating the size of the jets are stamped on the jets themselves.


Main jets – Found in the fuel bowl--> #24 and #24A in the photo (primary and secondary)
Idle jet – Primary and secondary are located on opposite sides of the carb --> #38 and #38A in the photo (primary and secondary)
Air correction jets - You can see them from the top looking down into the carb but requires removing the top of carb to replace them --> #79 and #79A in the photo (primary and secondary)

[deejay1272]

This thread has been very informative so far, but i'm not clear from anyones comments yet just what the best jetting is for a 3A engine at sea-level in warm humid conditions.

@gmeddy: this is what the guy at Redline told me about proper jetting at sea level for a 1.5L Tercel with zero performance mods:

Main jets – should be 140
Idle jet – primary (smaller venturi) should be probably .45 or .50 and the secondary the same
Air correction jets - Should be 160 primary – 170 secondary

I have no idea if this is accurate or not. I was planning on diving into this in a few weeks, so if you figure things out, then please let us know. I also live at sea level so I imagine that we'll be jetting our carbs the same way. PM me if you'd like to chat in person to share ideas...

[dlb]

great diagram, thanks deej!

[danzo]

Yes, thanks DJ for the info. Splatter, if you are reading this, do those jet settings make sense to you?

[gmeddy]

thanks for the info DJ, I will hunt down an australian seller of Webber jets, as I did once before but have now forgotten who they were and order what i need once I've pulled the top off to see what's inside.
i'll ask them for their suggestions on jetting for our needs too so we can compare what you were told.
thanks

PS, I dont know why my images would not be showing, they show up whenever I look at the threads, even when i'm not signed in...
if you want to see the shots i've got of my weber and condition of my plugs, here's the link to them

http://www.dropbox.com/gallery/17134827 ... m?h=91875e

[deejay1272]

Main jets – Found in the fuel bowl--> #24 and #24A in the photo (primary and secondary)
Idle jet – Primary and secondary are located on opposite sides of the carb --> #38 and #38A in the photo (primary and secondary)
Air correction jets - You can see them from the top looking down into the carb but requires removing the top of carb to replace them --> #79 and #79A in the photo (primary and secondary)

I'm revisiting this thread because I'm finally ready to put some new jets in my Weber. I've found that i have a bit of stumbling at low throttle and my MPG is not quite what I think it can be (currently hovering in the ~28 MPG range). The reason for the post is that I need to get some help on determining proper jet sizes. Here goes:

This is what I am currently running in the used Weber 32/36 that I got off Craigslist a while back (I finally found time to see what I have):

PRIMARY:
main jet = 140
idle jet = 60
air correction = 160

SECONDARY:
main jet = 110
idle jet = 50
air correction = 170

First thing that seems weird to me is that my main jet sizes are so different in size (a 140 and a 110 seems like a big difference). Does anyone know what jet sizes I should run if I want to maximize fuel economy at sea level?

[gmeddy]

I just got off the phone with a carby tech and he was not very happy about the idea that he give me advice and not make any money out of it.
Even after I explained that I live 5000km away... I guess he didn't believe me...

but he did ask what I have and said that a 32/36 is way way too big a carby for our little 1.4 tercel engine.
he said i should have a 28/30 carby.
the 32/36 cannot get enough air suction from the small tercel motor he reckons... anyway I've got a 32/36 and i'm not spending more money to change carby's now thats for sure!

so here's the jets that I am actually running

Main fuel:135
Secondary 130

Air: 150
secondary 165

Idle 55
Secondary 50

I have also got a 50 and 45 for my main idle, so I can change that back to 50 so they are both the recommended sizes.
but I should probably order the 140's for fuel, and a 160 and 170 for air.

anyone get any further experience with sea level perfect jetting?

[Petros]

I thought I would add my experiance with the weber jetting which I experimented with today. I drove it from Texas to Washington state (about 4000 miles) as it came from the previous owner. It was difficlut to keep running when cold due to the choke being way out of adjustment, and it got poor fuel economy on the drive, plus it was a handful to drive in heavy traffice because it was gutless below about 3000 rpm, so you had to keep the rpms up all the time. Above 3000 it was powerful and ran fine.

it had in it (ran crappy below 3000 rpm):
main jets; primary 125, secondary 140
idle jet; primary 42, secondary 50
Air correction jet; primary 160, secondary 170

I changed it to:
main jets; primary 135, secondary 130
Idle jet; primary 55, secondary 50
Air correction jets; primary 160, secondary 170 (unchanged)

and I got the choke adjusted, and with the new idle jets installed it idles best with the idle mixture screw out about 1.5 to 1.75 turns out (which is what the recommended range is with the correct jet, so that solved the low end problem).

Now it starts and runs normally, and it seems to pull from the low end to the high end without any hesitation or dying off. So it appears this combination works well so far. I have to taking out for a day or tow of driving to see if it is fully "normal", but based on the test drive it is already in much better tune. I tried to match what Gmeddy had found worked, but I did not have all the correct sizes, so I got as close as I could. Seems to run well now. It seems to me with the slightly larger air correction jets in, it should run a bit leaner (if I understand its operation correctly), but not sure if it is enough to harm it. we shall see.