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| Weber DCOE Cold Starter Jets - Sizing https://ausmini.com/forums/viewtopic.php?f=2&t=100972 |
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| Author: | MINI66 [ Fri May 21, 2021 12:07 pm ] |
| Post subject: | Weber DCOE Cold Starter Jets - Sizing |
Hi there Is anyone with a weber on here actually using the cold start device on their weber? I am interested in what size starter jets you are using. My wife struggles with the current cold start procedure of 5 pumps and then light throttle crank to fire. Which works fine but I would like it to start nicely using the choke knob. I currently have 65F5 jets in a 45 DCOE on a pretty stock 1275 and these are not big enough. I almost get a stumble with full choke but nowhere near a fire up. If I use the choke it does however decrease the amount of pedal pumps required so it is doing something. I was thinking I need about 90F5 and have ordered some tiny drill bits, but don't want to go too far as the starter jets are expensive. Just after a baseline. cheers Rick |
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| Author: | Gambo [ Fri May 21, 2021 1:48 pm ] |
| Post subject: | Re: Weber DCOE Cold Starter Jets - Sizing |
When you say starter jets, are you referring to the idle jets? I had to blank off my choke/starting device as it was leaking fuel due to the manifold angle. This is my jetting, based on David Vizard’s How to modify your mini book. Running a 1275 with LCB extractors and a 45 DCOE, not sure if the cam but think it’s stock. 36mm choke 150 main jet 180 air corrector F2 emulsion tube 40 pump jet 50F2 idle 4.5 aux Venturi Cold start is fine, couple of pumps and it fires up. Have to give it a little accelerator due to the lack of choke till it warms up a bit. My idle mixture needs a bit of fine tuning though as it’s running a little rich. Sent from my iPhone using Tapatalk |
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| Author: | timmy201 [ Fri May 21, 2021 2:05 pm ] |
| Post subject: | Re: Weber DCOE Cold Starter Jets - Sizing |
I use the starter circuit/choke on my Dellorto. I don’t need any pumps or throttle to get it to start and idle. It does make it really rich, if you sit and idle it for a minute or so it’ll foul the plugs, so I normally start driving soon after starting |
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| Author: | MINI66 [ Fri May 21, 2021 2:19 pm ] |
| Post subject: | Re: Weber DCOE Cold Starter Jets - Sizing |
Hi Timmy Ok, cool. That's the outcome that I am after, don't suppose you know the size of the starter jets you have? Cheers Rick |
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| Author: | MINI66 [ Fri May 21, 2021 2:42 pm ] |
| Post subject: | Re: Weber DCOE Cold Starter Jets - Sizing |
Hi Gambo No, I mean the actual cold start circuit jets, not the idle jets. I have my 45 DCOE tuned perfect with jetting quite a bit leaner than you, but I am in a warm climate at sea level. My AFR = Idle 14:1, Cruise:13.5:1, WOT/ full load: 12.5:1 I get exactly the same fuel economy as the HIF6/44 SU that was on the car for run in of this engine, and no dreaded 'Untunable lean bog' that so many people warned me of. My jetting: Italian 45 DCOE 13 34mm choke 145 main jet 190 air corrector F16 emulsion tube 30 pump jet 40F8 idle 5 aux Venturi 60F5 Cold Start jet No dashpot oil! 1293 stock cam, LCB's Maniflow 1 & 7/8 twin box system. These carbs are great. I was previously an SU man but no longer (sorry purists). So, as you can see my setup in idle and pump jets is substantially leaner than yours, so it makes sense that yours would cold start much easier. My wife forgets that she has to pump the pedal 5+ times and gets the shits that it wont start. The cold start mech with the right jets should solve this. Cheers for the input Rick |
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| Author: | ausdino [ Fri May 21, 2021 10:21 pm ] |
| Post subject: | Re: Weber DCOE Cold Starter Jets - Sizing |
Hi Rick, I haven't played with webers for a long time. Below are the jets in the two webers I have and have used on my previous Cooper S's. Hopefully, its of some use and doesn't muddy the water any further. I will be using weber #2 on my Mk 2 currently under restoration, suitably reconditioned and re-jetted to suit the new motor. Your jetting: Italian 45 DCOE 13 34mm choke 145 main jet 190 air corrector F16 emulsion tube 30 pump jet 40F8 idle 5 aux Venturi 60F5 Cold Start jet My carbs: From what I can remember , both seemed very good on their respected engines - no flat spots. It worked particularly well with the 649, nice grey exhaust pipe. Weber #2 - Last used 1983 : 1310, period 35/75 cam & later a 649, lcb-1 7/8" single muffler, good head, balanced etc Italian 45 DCOE 13 34mm choke 130 main jet 175 air corrector F2 emulsion tube 50 pump jet 50F9 idle 4.5 aux Venturi 50F9 Cold Start jet Weber #1 - Last used 1980 : 1310, period 30/70 cam , sonic long 3-1 ,1 7/8" single muffler, mild head, balanced. Unfortunately, it has a broken flange when a mechanic tried to over tighten a bolt on the inlet manifold - hence weber #2 Italian 45 DCOE 13 34mm choke 145 main jet 180 air corrector F15 emulsion tube 50 pump jet 45F9 idle 4.5 aux Venturi 60F5 Cold Start jet For what its worth, I've never used a choke on any of my webered cars, ranging from the Minis to a Alfetta Gt and my Dino. Just a couple of pumps and start with a bit of throttle as others have previously said. |
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| Author: | MINI66 [ Sat May 22, 2021 11:57 am ] |
| Post subject: | Re: Weber DCOE Cold Starter Jets - Sizing |
Thanks ausdino. Those starter jets are also small. I will just have to start drilling mine out and see how i go. |
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