Webber 44 IDF idle circuit??

1969bluebug · Post by **1969bluebug** » Sun Nov 02, 2003 5:05 pm

Since I had my 44 IDFs on a 1915, 042 heads 009 dizzy, the #1 and #2 idle adjustment screws do nothing to the motor.

This has just been this way. I have tuned the car. It has electric ignition, petronix II with coil.

I have taken up the carbs and put new gaskets in.

So now with my new exhaust Kymco 1 5/8ths with a phat boy, I am getting alot of exhuast backfires on decelleration and some at high RPM's.

I have my fuel pressure set at 3.5 lbs.

I dont know how to adjust the float, since if the butterfly is closed and the idle screws are all the way in how is there gas still getting to that side of the motor?

Is there a good way to find an exhaust leak? Im pretty sure there is none.

Also I have a flat spot at around 45-50 in third if I stay steady on the gas, the car just seems to not fire correctly ( dont know if this is a flat spot) just sounds wierd from the exhaust. Not a constant groan.

So idle misture screws what would cause this?
And what is a flat spot sound like?, do all 009 dizzys have it?

thanks for your help

Greg Ward · Post by **Greg Ward** » Sun Nov 02, 2003 5:30 pm

What are the idle,main and air corrector jet sizes now?

How many turns out are the idle mixture screws?

How many turns on the idle speed screws?

One idle screw more turns than another can have the effect at idle you are describing, because it is running on half an engine e.g, the 3,4 side.

If you can answer the other q's above,maybe can help you more.

1969bluebug · Post by **1969bluebug** » Sun Nov 02, 2003 6:05 pm

Here are the carb specs
F11
52.5 idle
140 main
200 air

The idle screws on 3&4 are about 2.5 to 3 turns out.
Speed screws on 3&4 are closed.

The idle screws on 1&2 are the same as 3&4
and speed screws are out a little maybe 1 full, to even out both carbs to match 3&4
When I synched them I had to let more air in since it was not pulling as hard as the left side...

So any ideas? I dont believe there is an intake leak and I can seem to find an exhaust leak by holding my foot over the muffler and listening for a hiss or anyting...and no black soot by the header connections on the heads. The slip joints were a bitch to get on so I also doubt they are leaking.

Any idea about my flat or weird sounding spot ?

JEFF KYLE · Post by **JEFF KYLE** » Sun Nov 02, 2003 6:33 pm

Read this link to setup them correctly http://www.redlineweber.com/html/Tech/i ... ntrols.htm ,but every time mine have acted like that the idles have had trash in them.You should be able to see lite thru them.I have a strand of small wire if it will not blow out to get it out.I solved the problem by getting new K&N filters..the problem was dirty air,not fuel.

Float settings are very important too!!

Greg Ward · Post by **Greg Ward** » Sun Nov 02, 2003 6:42 pm

Ok,

So you are saying that the idle speed screw on the 3,4 side is totally shut?

I'd suggest you start from scratch. Only take you ten minutes.

Disconnect the arms from the linkage, so that has no effect, put both idle speed screws at one turn (very important start) put all mixture screws at a base of 1.5 turns.

Connect your arms again and make sure both carbs are opening at the same time. Look at each throttle stop and make sure they open together, one ahead of the other, even a small amount is no good. If you have to, unlock the nuts on the arm and wind it till they open the same amount just off the throttle stop, tighten nuts on linkage arm again.

Now you have done all that you can begin to sync the carbs!!

Start the car and let it idle, if it is too high, reduce it by backing off the idle speed screws by the same amount each side.

Now with your fingers, turn #1 cyl idle mix screw out until the engine runs worse or changes note, then back in to where it runs fastest.
Repeat for other 3 cyls.

If after all 4 are done and the engine is idling too high, then reduce idle speed , again do both sides evenly.

Now take it for a drive and see if the 4500 miss is still there.

Tom Simpson · Post by **Tom Simpson** » Sun Nov 02, 2003 6:53 pm

I agree with Greg on this. It really sounds like your carbs are out of sync and just need re-tuned...

drkoontz · Post by **drkoontz** » Sun Nov 02, 2003 7:42 pm

1969bluebug wrote:
The idle screws on 3&4 are about 2.5 to 3 turns out.

Speed screws on 3&4 are closed.

The idle screws on 1&2 are the same as 3&4

and speed screws are out a little maybe 1 full, to even out both carbs to match 3&4

1969bluebug · Post by **1969bluebug** » Sun Nov 02, 2003 8:38 pm

well to be honest I did start just as you said...

but when I got to 1,2 just trying it to get any form of change from

1 or 2 with the idle adjustment screws really did nothing..

I will start all over but for some reason I mean NO CHANGE AT ALL,

it doesnt seem to help or work.

Its getting dark here pretty early so hopefully i will have some time before dark to do this tomorrow
thanks for all the replies

rocky point mex · Post by **rocky point mex** » Sun Nov 02, 2003 8:45 pm

what is your maximum rpm?

what altitude will you be running at most of the time.

first first first.... check your floats since they determine the progression circuit.... 10-12mm from top and 28 to bottom

i ran your engine numbers and
if your running a 1915 at max 6000 rpm then 44 webers are correct.
you should be running about 36 venturies with 200 air correctors then you should be running 130 to 160 mains

if your idle jets are at 50 then you should be running just fine. turn them all the way in and then back out 1 1/2 turns. Find your lean best idle. sync up the carbs and if you still have backfire something is plugged. get out your cans of carb cleaner and the compressed air.

1969bluebug · Post by **1969bluebug** » Sun Nov 02, 2003 8:53 pm

not sure why?

I still have to put my tach in but my gas heater is kinda in the way of the dash for now.

I could hook it up in the car if you want me to read it

rocky point mex · Post by **rocky point mex** » Sun Nov 02, 2003 9:38 pm

set your fuel pressure betwen 2.1 and 2.8 psi

and by max rpm i'm looking for the fastest rpm you'll run your engine.

1969bluebug · Post by **1969bluebug** » Sun Nov 02, 2003 9:42 pm

not to fast or high rpms at all..

its my daily driver.
so I baby it plus I only now have my stock 69 tranny which is way old.

I got screwed over with my purchase a while back of a freeway flier and the dam thing blew up

Now I am saving up for a new one from a reliable place

rocky point mex · Post by **rocky point mex** » Mon Nov 03, 2003 5:36 am

ok lets say 5000 max would call for a 32 main venturi and 110 to 140 mains.... according to weber tuning manual. the procedure for the low speed jets remains the same. start at 50 and you'll probably work down to 45.

george brown · Post by **george brown** » Mon Nov 03, 2003 11:30 am

Idle mixture screws out 2.5 turns is way too much, they should be out about 1 to 1.5 turns. Make sure the idle air bypass screws are fully closed. Check the enrichment circuit to make sure the valves are seating fully closed. Check the idle air inlet bushings (brass, hole should be 115 with a Weber jet gauge) in the carburetor body top to make sure they aren't plugged up. Blow out all idle passages with compressed air to make sure they're clear.

When you set your float levels check the float needles and seats for sealing, and check the floats for leaks. A leaking float will sink in the float bowl and raise the float level, causing an over-rich condition.

Also check the fuel inlet on the carb top - clean the filter if necessary.

1969bluebug · Post by **1969bluebug** » Mon Nov 03, 2003 1:15 pm

I never adjusted the floats before can you give me a link or a detailed explanation in doing this thanks.