Never owned a carbureted truck before.

Is it normal for a carbureted engine to have exhaust that smells like gas?

I get the idea of running rich, but Im not seeing any black smoke or any bogging, but the exhaust still has a strong fuel smell and if my back window is open man do I get a good whif of it.

Should I try leaning out the carb at idle on the adjustment screws to see if it may be off?

Carb is a weber...

 

What is your fuel mileage??

 

With engine off count how many turns idle mixture screw goes before it lightly bottoms out. write it down. should be between 1.75, and 1.25 turns before it bottoms out. if its less then 1.25 turns idle jet is too big. more than 1.75 idle is too lean.

Idle speed screw should be honestly less then one turn after contact is made with stop.

Redline says 1.5 max on idle speed adjustment, but that opens throttle plates too far on my 32/36 and exposes enrichening holes also causing a rich condition.

 

is it a 32/36 or a 38?

above instructions are for 32/36.

you have 2 idle mixture screws on a 38.

38 is similar but baseline is a little less.

 

Hmm, not sure - how do I tell? it just says the serial which is #39662

 

Not sure yet, calculated 20 mpg driving 65 on the highway but that's the only measure I've gotten so far

 

20mpg is pretty killer. If no black carbon buildup around pipe, prolly good. May wanna just check lines including return to tank.

carb will have stamp on base. but around back @ accelerator linkage there will be 2 gears if its a 38.

also if its 38 it will have 2 idle mixture screws one on passenger side one on drivers.

32/36 just one idle screw on passenger side.

 

Looks like a 32/36 I'll try making the adjustment today

 

Wow, so I got 2.5 turns

Edit I guess this means the existing jet is too small ? That must mean that this has been re jetted before as I'm at 6500 feet in elevation...

I was able to push the screw in maybe a quarter turn before it started stumbling

 

two other things of note seems to have a slight miss at idle

And idle is set at 1k assuming the tach is correct....

 

ok so backed the idle speed screw down till the idle hit 750. Then leaned the mix screw in about 25% until she started running rough, seems the best I can do right now.

Good news is backing the idle speed screw out got rid of the miss

 

did some more searching about the need for a fuel pressure regulator on these webers with the mechanical fuel pump to avoid dumping excess fuel into the carb ...

Again the weird thing is she runs great , but definitely heavy fuel smell from the exhaust

 

Here's what I think is the existing FPR

 

Just got off the phone with LCE - Im gonna start with the proper fuel pressure regulator set at 2.5 PSI and then see where Im at at the carb.

Can anyone tell me if the piece above is even a FPR ?

 

That's a fuel filter.

 

factory mechanical pump is low pressure anyway. that stumble was because of idle speed screw being to far in. when you backed it out it closed those enriching holes in bowls. try to readjust the idle mixture screw now. idle mixture screw wouldn't have been doing naught if idle speed screw was too far in.

Honestly there are many people who disagree. but factory fuel pump was a low pressure pump and the need for a regulator is relative.

at this point its all in the tune. more than likely your floats need adjusting too.

 

Hmmm ok , LCE suggested a regulator and then rejet if that didn't fix things - maybe they were just trying to sell me a regulator ?

I had read that the mechanical pump is around 8psi and the webers like 2.5 ? That's just what I found when searching ...

 

I read in some old Toy literature factory pressure on the mechanical pump was between like 2.9 and 4.2psi the regulator is just something to throw at it.

 

no 20r or 22r mechanical pump delivers 8psi, that I've ever seen the specs on.

 

if you get one get a gauge too, and hook the gauge up first before you install regulator, and let us know.

There's lots of tuning on that carb.

Pull it off truck, pull the top plate off and see how its jetted do one side @ a time passenger side is primary drivers is secondary.

while your in there check float height. there are instructions and videos on the web to do it all.

to pop that top lid there is a little c clip or cotter pin, that holds choke linkage don't lose it and 6 screws. hardest part is that little clip imho. Doing it off truck you can confirm lower butterflies are not exposing the fuel ports in the sides of the barrels.

if you are running 2 piece adapter buy a one piece. transadapt makes a nice one.



post your jet sizes and we can go from there.

my 32/36:

Idle Jets 55/50
Main Jets 145/140
Air Corrector 180/170
Pump 55

my 38

Idle Jets 60/60
Main Jets 145/145
Air Corrector 185/185
Pump 70

neither setup run rich @ any circuit