hi im having problems with the webers if once you get the car running and idling reasonably if you push your foot to the floor quite quickly the car will bog right down and almost stall im totaly new to all forms of carbs as all the cars ive ever owned have been fuel injected so totaly ew to me but i would really like to learn

i have
34mm venturis
50F9 idle jets
125 mains
F11 emulsion tubes
150 air correctors
45 pump jets

the engine is standard at the minute apart from i have fitted the electronic ignition dizzy kits and the rest is all maintenance but some time soon i will be looking at a cam kit like the kent fr32 fast road kit

from what i have read and learned from the power tuning weber and lots of google reserch i have come to the conclusion the hesitation could be the idle/progression jets so im thinking 45F9 and the pump jets being to big so running masivly rich so thinking 35 pump jets

the more i read i seems like the air correctors are too small but dont know what effect these really have

sorry if i have missed something out like i say its my first car with a carb let alone 4 of them lol

thanks

Are the accelerator pumps actually squirting, often either the jets get choked or the pump or aren't getting pulled down when the throttles are opened.
The pumps are operated by a bell crank lever located between the throttle barrels, a tiny roll pin that locates the bell crank on to spindle often shears.

I know one carb is squirting as I have had it off and got covered in fuel when i flicked the throttle lol but will have a look at the other one later on

I get a puff of black smoke when it bogs so assuming it's running rich

Accelerator Enrichment pump is pouring too much fuel, there should be provisions to adjust.
HTH.

Turbosports forum is a great place for the very information you require.
They will also say that twin 40's are ok for a standard Pinto but you will need 45's if you upgrade the engine.

Pump jets are to big, as i suspect that your idle jets are too for the venturi sizes.

Check the float levels first though (it costs nothing), they have a huge effect on the transition stage especially with F11 emulsion tubes (which are also rich).

Ian

There is no adjustment I can see other than changing the jets was Gunna order some 35s and try that and was thinking 45f9 but only want to change one at a time so which would you do first

I wi have to do some research on setting the floatheight as I have no idea how to do it and what to set them too also could I increase the air corrector to increase the air fuel ratio on the main jets
Thanks for the help guys

Check the float levels first, you can measure it down to the fuel level with a vernier (remove a main jet/emulsion tube/air corrector assembly) or remove the carb lid and measure the gap between float and top lid when held virtical. Both methods are shown if googled.

Whilst the air corrector may not be right, changing them won't help what so ever with your problem, they're more for fuel adjustment at full chat high up the revs (in combination with the main jets).

Ian

I have been googling since the last post lol struggling to understand how to measure it I keep coming across 8.5mm which I think is the measurement when the lid is removed but sti a little unsure and 27mm I think which seems to be down the emulsion tube hole

Canyou just confirm for me I should be having the carbs level then remove the emulsion tubes completely slide the depth measurement side of the vernier down the tube and will it hit something or will it hit the fuel level ect and I would assume this should be done with the fuel pump running so as the bowls are full

Thanks

Have the pump running, and use a torch down the hole to see when you touch the petrol surface (very easy to see). If you do need to make an adjustment obviously the top has to come off the carb to do it any way.

Ian

Thank you for that and what measurement would you recomend for the floats

If i remember correctly 28 - 29mm down the jet hole, but it's more important that they're the same on both carbs. Check what they are, unless they're several mm less than that (= higher float level) then that's not the problem.

Ian

Thanks alot I will have a look this weekend and see what they measure and tweak if need be

Hi, how about buying some bike carbs and putting them on, sell the webers and spend the tidy profit off the sale and saving fuel to buy some thing nice?

Right I had a bit of a play and fitted some smaller pump jets which helped quite a bit it now does it occasionally I checked the fuel filters and they were clean so measures the floats and the front carb measured 31 and the rear carb was 32 does that sound okay and I have also adjusted the ignition timing and it's set at 13 btdc and it was about 8btdc which helped

If anything that level would make it leaner so that's not your problem.

Have you set the idle mixture screws?, if they're set overly rich it'll only make things worse. Set them as lean as possible and still have a smooth tick over.

Have you checked the carb balance?, if that's not right you'll also get a stutter and a rythmic rocking of the engine at tick over. Quite easy to check/set with a peice of pipe to the ear into the carb mouths.

Ian

I tried setting to idle mixture but wasn't too sure what I was doing I have read loads of guides on the net and thought I new what would happen when I tweaked them but nothing really happened when I tweaked the screws either way I tried the listening though the pipe but didn't really know what I was listening for lol They are all set at 3 turns out from lightly seated

I bought some vacuum gauges for balancing and I think it's bang on now as they were out and like you say the engine was rocking but now it's pretty smooth

[Edited on 29/9/11 by Autosri]

Adjust each mixture screw one at a time, screw it in until the engine misfires on that cylinder/it runs on the other 3, then slowly unscrew it until that cylinder runs again and as smooth as possible, then stop turning. Do the same to the other 3. Quite often you'll have to go through them a few times to get it just right. When they're about right any adjustment in or out on any of them will make the engine tick over slower/rougher.

If you had a wide band it would save you a lot of time and confirm your going in the right direction.

Ian

i will have another go on the weekend and see what happens i can always put them back as they were

im gunna be ordering a wideband kit from innovate soon so i can check the air fuel ratio but im getting it mostly for my main car for setting the nitrous oxide jetting