1975 2F Piggy with Weber 38 carb and DUI dizzy...need some insight please:)

[mydogpea]

You did that yourself! Nice work, mydogpea.

Thank you.

 

[JohnnyC]

I've gone off the DGAS sheet. The mixture screws are 1 turn out.

one screw out total? or off base line of 1 turn? so your out 2 turns?

if you are out 1 turn total...go out to 2.5 and report back

 

[jdog35]

That's not an adjustment. It holds the (idle mixture jet?) iirc and should be turned snug.

Copy that. I'll snug it down. I figured it should be snug since it has an o-ring on it. Thanks man. Case of beer to any of the local folks who can get this piggy running OR I will be HAPPY to trade some professional photos/video of you and your rig too. Trying to think outside the box here

 

[jdog35]

one screw out total? or off base line of 1 turn? so your out 2 turns?

if you are out 1 turn total...go out to 2.5 and report back

1 turn total. I'll try 2.5 out total. Thanks Johnny!

 

[JohnnyC]

ohhh and yes thats the idle jet ....the jet is behind that plug/screw..that should be tightened

 

[jdog35]

Okay kiddos. I am officially 2.5 turns out on the idle mixture screws. Both of them. When I start the rig it fires up okay, and idles VERY low (like 300rpm). Soon as I try and put a little gas into it through the throttle, it revs a tiny bit, then dies. And if I really try and goose it, it revs a little, chokes, and then blows a nice big puff of white smoke/exhaust out the top of the carb. Great for getting high, but not so good for actually getting this puppy running:/

I didn't want to play with it too much without some feedback first. Oh, and the timing light is set and clicking well on the bb. If that helps.

Thanks y'all!

 

[JohnnyC]

OK bring the idle mixture screw back down to 1.5 turns out on each....

Jdog are you timing the engine with the vac still hooked up to the dizzy? or is it off and pluged from the carb when you time?

on your DUI....did you install?

had you messed around with the dizzy at all?

 

[jdog35]

I'll crank them back in.

The vacuum gauge is not on the dizzy when I time it. The carb line is plugged into the dizzy.

I did not originally install the distributor, but I have reseated it so that it was pointing in the right direction and in the range of "turnability". The only thing I've messed with on it is that and advancing/retarding the timing based on the dizzy and either the TDC line or bb. Does that all make sense?

 

[JohnnyC]

you need to have the carb line off the dizzy and pluged in order to do timing...nothing need to be pluged into the dizzy when timing

set to 12* and report back

 

[jdog35]

Will do. Correct me if I'm wrong, but the bb is at 7* correct? So 12* is a little bit of an eye-ball measure? And with the vacuum gauge hooked up to the carb, I'm assuming I should be at somewhere around 20psi?

Thanks again for all the help Johnny. This has been a fun and frustrating adventure! I owe y'all!

 

[JohnnyC]

yeah if you dont have a timing light with a dial then yes...just a bit more advanced

 

[jdog35]

Okay. Got a line set at 12* I believe.

 

[jdog35]

Okay. At 12* the psi on the gauge coming off the distributor is 6psi. That isn't good is it?

 

[jdog35]

And when I close the choke plates on the top of the carb the psi holds right at 11-12psi. Hope this illuminates someone since I'm in the dark obviously.

 

[JohnnyC]

the vac nipple off the carb is ported vac...at idle it will be low to none...when the throttle is opened the vac increase....advancing the dizzy


there will be no vac off the dizzy....only from the port nipple on the carb...

1) so you timed with the vac line off the dizzy and you pluged it when adjusting the timing ....correct?

2) manifold vac is full vac at idle...like the nipple on post #45 should be...what is the vac there?

3) where is you idle now?

4) hows it run now? same? dies or not?

 

[jdog35]

the vac nipple off the carb is ported vac...at idle it will be low to none...when the throttle is opened the vac increase....advancing the dizzy


there will be no vac off the dizzy....only from the port nipple on the carb...

1) so you timed with the vac line off the dizzy and you pluged it when adjusting the timing ....correct?

YEP.

2) manifold vac is full vac at idle...like the nipple on post #45 should be...what is the vac there?

At idle (500-ish rpm), with the butterflies closed in the carb, the vacuum gauge read a solid 20psi at this port.

3) where is you idle now?

Right about 550rpm

4) hows it run now? same? dies or not?

Still dies when I apply any throttle:/

 

[JohnnyC]

do you have an oem dizzy and coil to put in to exclude the ignition as being a culprit...just incase the po did something wacky to the dui?

is the dui a store bought? do you know? or a junkie find HEI by PO?

 

[JohnnyC]

also check to see if you have a full 12v going to the DUI ...if you have a coil + wire thats supplying only 8-9v that would be an issue.

 

[jdog35]

do you have an oem dizzy and coil to put in to exclude the ignition as being a culprit...just incase the po did something wacky to the dui?

is the dui a store bought? do you know? or a junkie find HEI by PO?

I don't have the OEM dizzy unfortunately. Wish I did at this rate. It was a store-bought HEI because I still have the receipt from his original purchase. I'll throw a volt-meter on it tomorrow. And the kitchen sink.

Thanks Johnny!

 

[JohnnyC]

you could pull it and have the module tested at an auto store...

are you confident its not in 180* out?

you may want to bring #1cyl up to compression and check that timing is on and that the firing order is correct (1 5 3 6 2 4)