All these jets!!(Weber Re-Jetting)

[matl59]

I just swapped out my solex for a weber 32/36 DGEV last weekend. It was brand new from OGTS and after install and adjustment to the best of my ability I seamed to be running on the lean side according to the instructions with the carb. I turned the mixture screw in and the rpms dropped as the instructions stated. From that point I turned the screw out and it never really reached a spot were it ran worse even after several turns out. The Idle speed screw is about a half a turn in. It idles fine (something the solex never did) but bogs pretty bad right off idle. It then accelerates good but at steady speed the motor surges. No noticable smoke from exhaust. My current jets are as follows,

Primary idle 60
Primary air 170
Secondary idle 50
Secondary air 160
Emulsion tubes are F50
main jets are 140

I am at sea level, the engine is a 1.9 bored to a 2.0 but otherwise stock as far as I know. Stock intake, aftermarket header. Anyone have some suggestions as to what jets I should try out? I have no Idea other then the instructions saying that I need a larger idle jet. Any help would be appreciated.

Thanks

[RallyBob]

Connecticut uses pretty heavily oxygenated gasoline, I've found that over the years carbureted cars have had to be jetted richer and richer to compensate in this state. It used to be that the winter fuel blends required two full jet size enlargements to even run (back when I drove Opels in the winter still).

Bob

[matl59]

So would you suggest that I try increasing the primary and secondary idle jets one size or two and see what happens? Would this change alone possibly fix my bogging and pulsing at speed? If I change the idle jets two sizes should I change the main jets or primary and secondary air jets as well?

[RallyBob]

Originally Posted by matl59 So would you suggest that I try increasing the primary and secondary idle jets one size or two and see what happens? Would this change alone possibly fix my bogging and pulsing at speed? If I change the idle jets two sizes should I change the main jets or primary and secondary air jets as well?

I would not make large incremental changes. Two sizes on the idle jets is a lot, but keep in mind a change in the main jet affects the idle jet (since the idle jet is fed its' fuel from the main jet).

So perhaps one main jet increase, re-adjust the air-idle mixture and see how it runs. If this is not enough, then try one size larger idle jet. I suggest adjusting one barrel of the carb at a time too, starting with the primary side for driveability.

Bob

[matl59]

thanks for the input, I'll take your suggestions into consideration when I order new jets.

[cbehm]

I too have bored out my engine to 2.0, I have new flat top pistons, torquer cam, aftermarket header, pertronix ignition and the weber 32/36 DGAV. I'm lost on what jet sizes to order. Currently I have to have the speed screw turned just about all the way in and the mixture screw backed out about 5+ turns just to get an ilde. I've checked for vacuum leaks and couldn't find any. I believe I need to re-jet. Let me know what you think about jet sizes.

Thanks.

[GoinManta]

I am going to get a straight concise answer on this sooner than later.. I know most these questions in one form or the other have been asked, but I don't think any of them have completely answered concisely in one thread. Hopefully I can artfully ask the question so all us that haven't jetted carbs can get a better feel for it. Because I find it intimidating and bit like voodoo..

Emulsion tubes

1A) Emulsions tubes do what?

1B) IF you only change from F50 to F66 or vice verse what happens?

1C) What is affected as far as the other jets go?

Main (Fuel) & Air Jets

2A) I assume increasing main jet size increases fuel to barrels - Thus richer

2B) I assume reducing main jets limits fuel - Thus leaner

2C) I assume reverse is true for air jets

2D) If running lean is better to increase main jets or reduce air jets?

2E) If running rich is it better to put smaller main jets in or larger air jets?

2F) How can you tell if you have to go with air or main jets when your dialing in the carb?

2G) I assume that if the carb is running rich or lean you dial these jets in and not the idle jets.

Idle Jets

3A) I assume primary purpose is idle

3B) Where do you start with these? Is it best to start with a set of 50s and get the air and main jets dialed in and then deal with them.

3C) What symptoms would one see from improperly sized idle jets? But you have the main and air jets right...

Walk-through..

Could you walk us through the decision making process in which set of jets you start adjusting and when you go to the other parts.

How can you tell if the Primary or Secondary is dialed in, but the other side isn't. I.E. the primary is perfectly set the secondary is out of whack, or vice verse.

If you carb gurus could simply explain these things, I think the "magic' of the process would disappear for a lot of us. I am about to put the 32/36 double pump on my sons Manta and know I will have to play with the jets.

Thanks,
Charles

[73 gt man]

Talking about jets, I live in Phoenix with a 32/36 water but also have an electrical line to it so what is going on with that and what jets do I need as I am rebuilding within the week, I am at a little over 1000 ft in elevation.

Thanks

Sean

[baz]

Originally Posted by 73 gt man Talking about jets, I live in Phoenix with a 32/36 water but also have an electrical line to it so what is going on with that and what jets do I need as I am rebuilding within the week, I am at a little over 1000 ft in elevation. Thanks Sean

its an electric assisted choke (comes off even quicker )
cant help on chokes as im at sea level

[cees]

My engine is the same as yours and I have the following jet sizes;

primary main jet 140
secondary main jet 140
secondary idle jet 50
primary emulsion tube 50
secondary emulsion tube 50
primary air correction jet 170
secondary air correction jet 160
accelerator pump jet 50

The car drives great! Please make sure your float assembly has been set correctly and that you are not flooding the engine with petrol.

[nobody]

Cees, long interlude between posts, hope all is well with you and your very nice yellow GT. Don't be such a stranger.

[RallyBob]

Originally Posted by GoinManta Because I find it intimidating and bit like voodoo..

Where'd I leave that Goin voodoo doll anyway?

[73 gt man]

How can you tell if the float is set correctly

[GoinManta]

Originally Posted by RallyBob Where'd I leave that Goin voodoo doll anyway?

Well arent we the smart butt Would you mind answering the post ?

[kwilford]

Go to:

http://www.opelgt.com/forums/aftermarket-down-draft-carbs/6765-final-how-jet-weber-thread.html

with your answers

[GoinManta]

Originally Posted by 73 gt man How can you tell if the float is set correctly

Proper way is with a very thin MM ruler.. I dont have the dimension handy.. but its in my Weber book and I will get it for you.

You can also eye ball it..

The flat bottoms of the floats when the top is upside down should be parallel to the face of the top. Looking at it from the side.

But like timing your car by ear or setting the points with a matchbook cover, it will be close enough to run but not perfect.

Charles

[RallyBob]

Originally Posted by GoinManta Well arent we the smart butt Would you mind answering the post ?

I already have on most counts....just gotta look over three year's worth of posts. It would take a considerable amount of time to re-write all that info on one post. I suspect a few thousand words at least.

I'll answer your last two questions though.
Always get the main jet correct first. It feeds everything else in the system. If you get the idle jet perfect, and the air corrector perfect, and then change the main jet, you'll have to start tuning all over again since everything feeds from the main the jet. In other words, build the foundation before you put up the first floor!

Get the primary barrel dialed in first. It does all your idling, and all your normal driving duties. The secondary is for power only. Often if I am short on time I'll dial in the primary side, and will 'get to' the secondary tuning later on....often weeks later. Also, if you concentrate on the primary side, then when you get around to the secondary you won't have to worry about the effect the primary side has on the secondary when you're at full throttle.

Bob

[Travis]

Only three years Bob? Here's one of Bob's better posts on carb tuning from 03/01 on the classicopels list

-Travis

-------------
>I need some advice. I had a standard 32/36 Weber on my car running great,
>>smooth idle, smooth take off, running clean, plugs looked great. BUT... I
>>have a "double pumper" 32/36 that I just installed on the car. It
>>has accel. pumps on both barrels
>>instead of just on the primary like the standard Webers. With this carb,
>>the car will tear up the brand new 195-60-14 tires. The difference in
>>power is amazing.



*****Same throttle bores, same venturis. There should be no difference in
power unless one is badly jetted. The throttle response however, is notably
better with the double pumper (IF correctly calibrated, otherwise it may be
worse)


>>The only problem is the car has a bad stumble when you first mash the
>>pedal, the engine stumbles then the revs scream and the car takes off. >>I know it is running
>>way rich, when I rev the car in nuetral it stumbles and emits a puff of
>>black smoke, and the plugs are a bit sooty.


*****The secondary accelerator pump is actuated only when vacuum drops in
the secondary venturi, so at that point more fuel is squirted into the carb.
After confirming the main jets and air correctors are the same as the
regular 32/36, try installing a smaller secondary idle jet, this is what can
cause the stumble you spoke of. Normally, the secondary idle jet does ALL
the fueling when the secondary throttle plate initially opens, but with the
extra pump shot, it will likely be too large.

>>The mixture screw seems to
>>have little effect on the idle quality other than the fact that when it is
>>all of the way in, the idle speeds up a bit.


*****Bingo. If it gets smoother when you screw it in (leaner), then the
primary idle jet or main jet is too big. Remember, the main jet feeds
EVERYTHING. The idle jet is a fine-tune of the main jet for the low rpm
circuit (between idle and 1500 rpm's or so), and the idle mixture screw is a
fine-tune of the idle jet (affects idle and just off-idle only). Changing
the main jet means re-adjusting everything! (i.e., new idle jets and idle
mixture)

>>The idle mixture screw on
>>the carb I had on it before was extremely sensitive. I dont think I have
>>any vacuum leaks, I cant hear the usual hissing indicative of a leak.
>>
>>My question is: does anyone have any tuning advice for this carb? I have
>>a few extra idle jets around that I could swap in. I was running a 45 pri
>>and 55 sec and the car really screams, but it stumbles on throttle tip
>>in (these are the same as I was running on the other carb that ran great).
>>Could it be that the mixture is too rich everywhere? Why does the idle
>>mixture screw seem to have little effect?


*****Check the main jets! Even if the idle jets are the SAME, if the mains
are bigger on one carb, that carb will run richer even in the idle range.
The idle mixture screw is a FINE adjustment. If everything else is out of
whack, it will do virtually nothing.
Wanna know how I baseline my main jet settings? Gotta tune it barrel by
barrel. I'll set the idle speed screw for about 3500 rpm's, and walk away
from the car for 5 minutes. If it's seriously lean, and you're worried abot
doing damage, don't worry, there's no loading on the engine, and a very lean
engine will "pop" and sputter significantly enough to warn you. After the 5
minutes are up, I'll shut the engine off clean. Don't drop the rpm's! Now
check #2 spark plug. Why #2? It runs the leanest, at least on a 1.9 head.
If I'm happy with the color of the plug (light brown to tan porcelain),
then I'll "rough-out" the tuning of barrel #2. Bring the idle speed back to
normal, in fact, close the primary throttle plate down to nothing. The car
won't idle, but while you're dropping the idle speed down via the idle speed
screw, start to open the secondary throttle plate by hand. Back off the idle
speed screw completely so the primary throttle plate is out of the picture.
Now, keep in mind you won't have very good throttle "tip-in" on the
secondary side unless you have a double pumper, but that's not what we're
after right now. Open the secondary throttle plate up enough to maintain the
same 3500 rpm "idle" speed, and retain the linkage so the rpm's hold. A
screwdriver inserted into the linkage should work, or needle-nose vise
grips. Wait 5 minutes until the plug gets colored up, and shut the engine
off clean. This time, I strive for the same color plug as the primary, but I
will immediately go up 2 main jet sizes on the secondary side to get more
fuel for better power. Remember, the primary side is your economy and
cruising barrel, the secondary is for power. Now, time to check idle jets.
Bring everything back to "normal", set the idle speed and turn the idle
mixture screw for smoothest idle, or about 1/4 turn out from the point the
rpm's start to drop. Hit the throttle and feel for the bog. Sputters, pops,
bogs or backfires? Probably a lean miss, you'll need to increase the idle
jet, reset the base idle, and readjust the idle mixture screw. Keep testing
until it's crisp. Black smoke or a SLOW bog on tip-in? Probably rich. Rejet!
Next I try cracking the secondary throttle plate on its own, without
the primary. Yes, it will bog a lot. But keep messing with the secondary
idle jet until a slow tip-in is smooth. Now try to crack the primary and
secondary together, and see if it's boggy or crisp. If you got the secondary
idle jet right, it'll rip! Lastly, there's the air correctors.
Realistically, you can only tune them by taking it out and romping on it,
then checking plugs again. As a baseline though, expect the air correctors
to be about "30" to "45" higher. By this I mean, if you have a 140 main jet,
you'll probably need somewhere between a 170 to 185 air corrector. The
exception is with a hot cam, it'll need about "20" to "30" higher, this will
allow less air to emulsify at higher rpms, making the mixture richer at
those rpms. This is VERY basic, and I always fine-tune on the road or track,
but you can get yourself 90% of the way there in your driveway this way.

Bob Legere

[cees]

Hi Gary, nice to hear from you. I trust you are well Indeed, I should participate a lot more. I am not as active as my New Zealand friend Jim.

My car goes great, especially after I fitted Koni dampers and I installed sway bars. I highly recommend this combination to everybody, as the road holding has changed dramatically. It is beyond me why Opel did not fit sway bars to the American GT versions as standard!

[tekenaar]

Originally Posted by cees Hi Gary, nice to hear from you. I trust you are well Indeed, I should participate a lot more. I am not as active as my New Zealand friend Jim. My car goes great, especially after I fitted Koni dampers and I installed sway bars. I highly recommend this combination to everybody, as the road holding has changed dramatically. It is beyond me why Opel did not fit sway bars to the American GT versions as standard!

Simple . . . $$$$$$!!

[73 gt man]

Does anyone know where the video was posted for the weber rebuild I have the kit for mine and would like to rebuild it today, I have a 32/36 I will find out what jets I have and repost later.

Sean

[BQS4]

Sean;
You need to ask "opeldean" real nice and he'll send you one.

[73 gt man]

Here are the numbers from my jets, I am not sure where the idle jets are so I do not have those numbers.

Pri 160
Sec 170 (almost looks like 710 or 770)
mains both 140

this is not the way it is supposed to be is it?

And where are the idle jets?

[opeldean]

send me your address, i will mail you the dvd. its all on there.



the cost is $5 to cover shipping/the dvd and the label.

[73 gt man]

I need some input please I am finishing my carb rebuild and I need to reveiw the jets I am at 1000 feet in elevation and my jets are as follows

Pri air 160
Sec air 170
both mains are 140
I am pulling the idles now but I have the california weber with the solenoid on the side with the pri idle

as always I appreciate it, Dean your video was awesome thank you for the help, my carb is just like yours the money is on the way.

Sean