TheSamba.com :: View topic - Injector tube accelerator pump/carb issues

Sat Nov 20, 2010 3:00 pm

I have a 34-PICT-3 carb, upon cleaning and trouble shooting , I noticed that my injector tube was missing...so...I ordered one from MidAmerica. The one they sent Part # 378-962 has a base diameter that is too big (will not fit down into pump opening... is ther more that one injector tube for this carb??
My car is a 67, but has a 73 engine in it (1600)

Sat Nov 20, 2010 3:20 pm

Just for clarification. Mid America ordered what I sent...I am not intending to blame them for anything. I am likely the dummy here.

Sat Nov 20, 2010 3:27 pm

If my memory serves me the jet is a tapered to fit in the body of the carburettor as an interference fit and therefore wont drop fully in place

Sat Nov 20, 2010 4:57 pm

This injection tube wouldnt go in unless you pounded it with a hammer...not tapped it, but pounded it. That bugger wasnt goin in without a fight.

Sat Nov 20, 2010 11:40 pm

How does the dump-jet they sent you compare to these? I'm pretty sure the one at the far lower left ought to be what you'd need in that 377-1 carb.

-Andy

Sun Nov 21, 2010 6:49 am

It does look like the one on the lower left, except that the neck rises strait up out of the base a bit more before making the turn. My problem is that the base part of the fitting will not go into the orfice on the carb body....or do I just need to force that thing???????????? im afraid to break the carb. I DID use a hammer and a screw driver to tap it in as Bug Me video indicates. Even after tapping part way, I had to use pliers to get it back out...wasnt even half way there??

Sun Nov 21, 2010 2:59 pm

Sounds they got the taper at the bottom wrong. I was wondering if my photo was large enough for you to be able to compare that as well.

Mon Nov 22, 2010 4:22 pm

Make sure the base of the old dumptube isn't still stuck in the carb body.

When you do succeed in getting it in place, aim the tube so it misses the side of the throat and doesn't hit the edge of the throttle plate when opened. The easiest method is to aim it when the bowl is full of fluid, or at least has enough in it to give you a few good streams when you activate the throttle/accelerator pump. 34mm carbs are notorious for stumbling off idle because of mis-aimed dumptubes.

Mon Nov 22, 2010 7:35 pm

They are also notorious for flat spots because people see the little "+" and "-" adjustments on the accel pump linkage and crank them all the way over to + thinking it'll help. When in reality it adds play to an already worn-out linkage and sometimes it won't start to spray until the throttle is half open. I adjust that linkage until all the play is taken up, and that's almost always to the "-" side of the adjuster. I had one so worn out once I had to have it all the way on the "-" side!
-Andy

Wed Nov 24, 2010 6:45 pm

As a follow up, I talked with a tecj\h guy at Mid America today. He told me there is only one o those things made. (I didnt mention the picture posted above o the 7 or 8 different ones.) He recomended using a little sandpaper and trying to sand down the base of the tube till I can get it in.
I guess Ill give that a go this weekend.
Does that sound feasible to you guys??
BTW, yes, the base of the old is not still in the hole.

Wed Nov 24, 2010 8:35 pm

I think he meant that only one part is currently available for them to sell as a spare part.

In that photo there are doubles - I just grabbed all the ones in my spare parts box and threw them down on my photo scanner. And I'm not sure offhand which ones came out of German, Brosol, Bocar, etc carbs. But that one at the lower left I did go and remove from a German (a 1972 VW325-2 base number) 34PICT-3.

The 28 and 30 PICT series, having a smaller venturi, those didn't need to have accelerator pump tubes that extended as far out as the 34s did.

I think at this point, if you want to make that part work, sanding it down is probably your only option. I'd use some really fine sandpaper on it.

-Andy

Wed Nov 24, 2010 9:01 pm

it is my experience that the replacement ones don't work well for the 34 carb. The taper is wrong. I don't know if sanding will help. I always sourced an original.

Sat Nov 27, 2010 11:36 am

Well, I got it in there. It took a bunch of sanding, but its in and there are no leaks. It definitely seems to run better! Flat spot and hesitation is gone. there is no way that I would consider that tube I bought a perfect fit. Tape is wrong. Istill didnt seat all the way to the flange of the base, but after some "fine tuning, :evil: its in....just in time to put the car away for the Western PA winter!!! Yuck!!

Sat Nov 27, 2010 11:58 am

They don't usually go all the way in until the flange seats. You can see the witness marks in most of the nozzles in Andy's excellent reference photo, about 3/4th's way is normal.
As long as you got it in and it seals, and most importantly doesn't come back out, you should be okay..

Sun May 20, 2012 12:39 pm

Thought I would bring up an older thread as I am having a similar problem...

I am currently rebuilding a Solex/Bocar 30 PICT-1 carb and the injector tube is extremely loose fitting back into the carb and will not stay.

I have other Solex 30 PICT-1's and it fits perfectly in each one...

My question is do Solex - Solex/Bocar carbs use different size injector tubes?

The injector tube is identical to the one in question above, the bottom far left tube in Glutamodo's pic.

Any help would be awesome, thanks.

Sun May 20, 2012 7:57 pm

I never realized the BOCAR units were that different there...I just went and dug up a bare BOCAR 30PICT-1 carb body and tried putting in those various dump tubes as seen in that photo above, to see if they'd fit. I don't know which one came from that BOCAR carb. Most of them were too loose for a reliable fit, but I think a few of might fit tighter if the carb was drilled out further down so they could seat down further.

There was only one that I thought fit tightly, and that was the one in the middle on the left side of that photo.

-Andy

Mon May 21, 2012 1:14 pm

Thanks Andy!

Going to track down some dump tubes to try out...

I too only had the Bocar body and wasnt sure what tube was used.

I also thought maybe the carb was drilled but as far as I can tell it hasnt been. The dump tube I was trying was close to bottoming out also... I would say there is only a 1/16 before it does... so maybe it has?

The Bocar carb body is the only core I have anymore as my Solex throttle shaft is beyond worn. :cry:

Again, thanks Andy, you are a true asset to this site!

Mon May 21, 2012 1:56 pm

You're welcome. Also, I just dug up my NOS Bocar 30PICT-1, date code on the base flange of 2777 (I think that means week 27 of 1977) and took the accel pump dump tube out of it and compared it to that other one. They were different... and that other one was too tight of a fit. Bocar also could have changed the design over the years as well.

Here's a photo:

-Andy

Fri Nov 02, 2012 3:19 pm

does anybody know where to buy online one of these little things for my Solex/Brosol h30/31 carb (made in brazil) carb?

mine seems to be faulty.

Wed Mar 01, 2017 8:43 pm

:popcorn: