Hey all.

I'm putting a 31PICT Carby on the 1600 twinport engine that's in the Baja.

I was just wondering what jet sizes people would recommend with this setup?

Currently main is 130.
Looking down the throat the air correction appears to be 110.

Also does anyone know what these jets are on the RHS of the carby? One must be the idle but what's the other?








The one on the right is a g52.5 and the one on the left is also a g52.5.

Which is the idle and what's the second jet for?



Smiley

Read here

http://www.thesamba.com/vw/forum/viewtopic.php?p=4378212 

Seems to be a bit of history with these carbs

Ok.

So the carby is on the car now.

Runs quite well, but it won't idle.

Timing is set to 32° advanced and that's around 10° at idle.

As mentioned above main jet is 130.
I've changed one of the jets on the RHS to a 55. Then swapped them. No real difference either way.


Can anyone advise what the problem is?


Smiley

Do you mean it will not run at idle speed? Or it can't idle: ie. it runs above 1000rpm all the time?
Maybe one of the jets has been plugged to act as a 'blank' to fill the hole where a e-mag cut-off idle jet was.
The idle jet should be the one to the left as shown in your pic....?

The second Idle jet on the 45degree angle is the aux power jet.

If you're getting a hesitation on acceleration in the mid range you need to go bigger with it.

I ran a few of these on 1600 twinports, those sizes are still for the stock 1300tp, it should still Idle slightly though.

I'll check when I'm in the shed what sizes I went with for a 1600DP

It took alot of trial and error but I got it set perfect from idle to redline.

Just had a look the same carb I've got on a bog stock 1600Dp with 4into1 header and quite pack muffler has a G60 in the power jet (left one) and a G55 in the Idle jet on the right.

That took alot of experimenting to get right but it was dead smooth after all that though

I would say it had a 135 main jet too.

Thanks.

I'll have to buy some larger jets.


Smiley

The one on the left (at 45deg angle to body) is the idle jet, original size g52.5.
The one on the right (at 90deg angle to body) is the aux. fuel nozzle, orig. size g45.

So the idle is the one one the left.

The main should have x130 originally.
The air correction jet/emulsion tube should have been 170W (maybe that is what appears to be 110 as seen from top?).

The cut-off idle solenoid (or its plug) should be on the other side of the unit. You need to set the idle bypass (large) and mixture screws (small) like on the 30Pict3.

Seems this setup was originally for a 1300 engine. The main will need to be at least about 135 probably.

Pffft I'm always right

joke, Brutus could be, to be honest I've never looked into it, I just ASSuMEd it was the idle jet on the right as thats stock postion on all other carbs and when I was having stumbling on acceleration at revs playing with the left jet sorted it, where as the right jet was more down low.

There's very little technical literature on these carbs out there, if you mention 31pict-3 on thesamba you will get crazy orrrstralian no such carb exists, but then they say that with 1300DP engines too.

Ok.

I'm still having the same problem.

Have just rebuilt the carby. Cleaned everything out completely.
Jets are as follows -

Main - 135
Idle - 55
Power Correction - 60
Air Correction - 110Z


Car still will not idle. It runs great as soon as the revs are up a little about idle, sounds very strong and revs smoothly. Have yet to take it for a drive. As soon as the revs drop down to idle it just cuts out.

Dizzy is 009, what should the timing be set to?
Could this cause it not to idle?

Any other ideas what the problem could be?

Just went and double checked the timing.

Is around 32-34 degrees at full advance.

Drops back to around 10 at idle before stalling.


Smiley

Is the idle with these carbys adjusted with the stop screw on the throttle arm like the early carbs?
Or is it adjusted with the bypass screw like the later carbs?

Or is it a bit of both?

I'm really at a loss as to what's not working.


Smiley

Throttle stop screw is ONLY for fast idle adjustment ie. while the choke is on. It should be set initially at about 1 turn in after it engages the fast idle cam when in the running position. Back the screw right out until you have an air gap to the choke fast idle cam, then screw it in to touch and then +1 turn. Idle speed is adjusted at the air bleed/bypass screw (the big one), then set mixture and reset speed then mixture again.

Didn't you have the pop-rivet in the throttle butterfly hole? Is it still there?
The main problem IMO is the 009....get rid of it or the 34pict.

I couldn't get the 34 to run, tried two different carbies and 3 different dizzys.

So I ditched that idea and went back to the 31PICt-3 and 009 Dissy off my 1300 that died. I've never had a single problem with tuning or running this pair. But now it's a no idle.

So I caved and just rebuilt a Bosch 014 Mechanical/vacuum advance dizzy and am about to tried that.


Smiley

What timing should this Dizzy be set to??

I can't seem to get it to run right at all now.



Smiley

Ok.

I give up now.

I've tried every single combination and every suggestion and idea that anyone has put to me.

The piece of shit still won't run.


Anyone want to buy a Baja? $50 and you can have it, I'm over this shit.


Smiley

You may have a manifold leak, Mr LookoutorImayjustburnmybajaSmiley.......

not if there's not enough fuel to idle up

why all the dissy changing?

Timing around 10* initial/30* total can't go wrong.

Just cause you put in new parts doesn't mean there's no leak, check with an aresol can of carb cleaner or the like.

Going out now... good luck

Quote:

And it does have the cutoff solenoid on the LHS of the carby. Smiley

Quote:

Originally posted by pod Quote: And it does have the cutoff solenoid on the LHS of the carby. Smiley is this still working??

Set vac total with vac disconnected, check idle solenoid with compressed air while powered