38/38 weber?

[Rasp933]

Klassic motion.

Thank you for pointing out the jets.i just took the jets out from the carb n it says 50 on them whereas the original jets that came wit 38s say 45.so iam guessing I should put back the 45s back on dat carb rite?

[KlassicMotion]

I would.  At least see how it runs.

 

You will have to change your mixture settings again, I'm sure.  As long as you've got the carb open, have you double checked the float setting?

[Rasp933]

I think I have to open may b 1/8 to 1/4 turn out .wen using the 45s .and how to check float settings?

[Rasp933]

U think a fuel pressure regulator is needed for this setup or this datsun fuel pump is ok wit it.? Cus I was reading bout webers its says the fuel pressure needs to b 3.5 psi or less for this carburetors.

[KlassicMotion]

http://www.classicinlines.com/WeberTune.asp

 

http://www.jeepforum.com/forum/f8/weber-38-outlaw-927959/index2.html

 

Both these links talk about the float adjustment.

 

The first link has a lot to say about fuel pressure regulators.....  I had not read that before, and I will go ahead and check the psi that my pump is pushing, and determine whether or not a regulator is necessary.

[KlassicMotion]

As far as the Dieseling goes;

This is what the 32/36 uses to stop that:

 

http://www.webercarbsdirect.com/product_p/43914.060.htm

 

I'm going to look at installing one of these on the 38 DGES.

[Stoffregen Motorsports]

http://www.classicinlines.com/WeberTune.asp

 

http://www.jeepforum.com/forum/f8/weber-38-outlaw-927959/index2.html

 

Both these links talk about the float adjustment.

 

The first link has a lot to say about fuel pressure regulators.....  I had not read that before, and I will go ahead and check the psi that my pump is pushing, and determine whether or not a regulator is necessary.

Quoted from link no. 1

"Fuel pressure regulators are OK with stock fuel pumps that put out too much pressure, however a regulator is simply a restricter which may inhibit flow. This can result in a huge loss of volume, which may result in the float bowl going low or even empty under hard acceleration. Regulators can also overload the fuel pump, causing a lot of noise and premature failure. Therefore, if you use a regulator with your stock pump, make sure it's a high quality regulator and that the fuel pump is supplying an adequate amount (volume) of fuel, and that it is capable of keeping the fuel bowl full at all times."

 

 

 

That's what I was saying. Those type of fuel pressure regulators (like the one in your pic) are intended to be used on the fuel return line so as to not restrict fuel flow.

 

A good fuel pressure regulator will not restrict flow, just pressure.

[Stoffregen Motorsports]

And then of course, you need a gauge to tell you what the puel pressure actually is.

 

[Rasp933]

Should I change my s/plug gap to .036.currently I have it at .040.my engine is outta 75 620 pickup.l20b.

[KlassicMotion]

If I remember right, the '76 L20B is recommended .35 gap.  I believe the determining factor is the Matchbox dizzy.  If you have a Matchbox, then leave it at 40.

[KlassicMotion]

Quoted from link no. 1

"Fuel pressure regulators are OK with stock fuel pumps that put out too much pressure, however a regulator is simply a restricter which may inhibit flow. This can result in a huge loss of volume, which may result in the float bowl going low or even empty under hard acceleration. Regulators can also overload the fuel pump, causing a lot of noise and premature failure. Therefore, if you use a regulator with your stock pump, make sure it's a high quality regulator and that the fuel pump is supplying an adequate amount (volume) of fuel, and that it is capable of keeping the fuel bowl full at all times."

 

 

 

That's what I was saying. Those type of fuel pressure regulators (like the one in your pic) are intended to be used on the fuel return line so as to not restrict fuel flow.

 

A good fuel pressure regulator will not restrict flow, just pressure.

 

I understand now what you were saying.  I will buy a fuel pressure gauge first, just to see what the stock pump is pumping, then I will look into spending the $$ for that pressure reg, if needed. 

 

And to answer a previous question, there is no return line on the stock carb, or the downdraft Weber.

[Rasp933]

I think I got it to where I dont c carbon on plugs.no missing at low rpms.no backfiring on deceleration or acceleration.swapped back in the original jets .had to open both bores like another 1/4 turn .regapped s plugs gaps at .035 to factory spec.and also the plugs r kinda turning brownish in color.

[Rasp933]

Wit no fuel pressure regulator

[Sealik]

A fuel pressure regulator is not needed if the factory fuel return line is functional

Which should be a given if at all possible....return all that unused underhood fuel back to the cooler gas tank

No adjustment of float level is needed on a new Weber

 

Typically when a stock CR engine runs on (diesels).....it's either too hot, timing is out or idle is too high. 

 

 

[Rasp933]

I got alot of good info from guys on here (ratsun ). Which I used n got the motor run where it is now .thanx guys

[KlassicMotion]

A fuel pressure regulator is not needed if the factory fuel return line is functional

Which should be a given if at all possible....return all that unused underhood fuel back to the cooler gas tank

No adjustment of float level is needed on a new Weber

 

Typically when a stock CR engine runs on (diesels).....it's either too hot, timing is out or idle is too high. 

 

There isn't a return line on the '68-73 510.  Just a vent line from the tank that uses a (pre-charcoal cansiter) three way valve.

 

Dieseling also seems to be an issue with this carb and the L20B with the large open chamber heads.  I don't remember what the reasons are, but that has been posted in another thread.  The main reason being, this carb is designed for off road use, and does not come with an idle circuit cut off like the 32/36 does.

[KlassicMotion]

Assuming my pressure gauge is calibrated, I got 4.7 psi out of my stock fuel pump,  static....  I will keep running a fuel pressure regulator, albiet I will upgrade the one I have to a better one, but you guys can keep running your carbs without one...  Personal prefference, I will go with what the manufacturer suggests. 

[banzai510(hainz)]

on a 38/38 I just push the pedal down slightly when shutting the Key off.

This will loose vaccume to the carb and shut down hopefully EZER with out dieseling

[Sealik]

There isn't a return line on the '68-73 510.  Just a vent line from the tank that uses a (pre-charcoal cansiter) three way valve.

 

 

 

Well...there is a factory return line on my 69 510

[Stoffregen Motorsports]

Well...there is a factory return line on my 69 510

Isn't that a vapor return?

[KlassicMotion]

Well...there is a factory return line on my 69 510

 

Do you have a pic? My '69 didn't have a return line.  Just the fuel vapor line.  The fuel tanks are not vented through the cap, they are vented forward to the carb.  The vapor valve is on the driver's strut tower.  Is your car stock?  Or, did someone convert that line in the past, to be a return line?