The dcoe 40 is causing the engine to stall when trying to take off, we have hopefully narrowed it down to the idle circuit having some issues.
I have jetted it to Vizard specs for a 1098 mildly worked engine, however the book also states that this set up is for 2.5 turns out on mixture idle screws, whereas weber suggest you should be between 3/4-1.5 turns.
I have a 50F2 idle...also tried a 50F12 with no luck...GR suggested maybe a 40F9.
Can anyone give any insight into even just cleaning out the circuit any similar problems they might have come across?

Sounds like is leaning out.
What are your other jets?
Pump jets are important too. They add fuel on depression of the throttle but stream at higher revs. Changing pumps often affects your main circuit.

Check the manifold is seated properly too, and check your timing.

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1970 Cooper S ex-Bathurst & ATCC
1964 Austin Cooper S ex-Group C race car
1967 Morris Cooper S ex-Group B
1962 Mini Speed sports sedan
1968-71 ex-Peter Manton Shell car

I know you've since thumped the firewall down but I hope the Weber isn't still hitting it when you accelerate. (bloody rodchange boxes...)
I like how Minispares said that manifold will let it clear...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I really hope it's not still hitting! I've made a decent gap under the rams and it will take off if I get it above 4000 rpm which is when I would presume the thing would hit the most. Not the ideal clutch releasing rpm though! Good old minispares... The weber hit even without the rams on!
I've got a 40F9 and 60F9 idle arriving tomorrow so we will see... Start with the cheap fixes and move on...I tried a 50F12 after the 50F2 and it did slightly improve. Slight timing changes have also helped. For some reason I can get reverse at slightly lower revs than going forward??
Bring the strobe tomorrow Kevin

Vizard jetting for 1098 with modified head, semi race cam and extractors:

34mm chokes
4.5 aux
145 mains
180 air corrector
F16 em tubes
45 pumps
50F2 idles

So Ive put this set up with a worked 202 head and an RE83 cam as suggested! Idles so well but nothing under load!

check your fuel lines, filter, and fuel pump

I checked the filter had no effect, how could I check the fuel pump?
It's a brand new facet. Fuel is definitely being delivered..

What pressure is the facet designed to deliver ?????

Although if the fuel holding device is full the weber pump should push enough fuel into the engine to get moving. Do you have a blocked jet ???

Mike

Problem solved!!
The float needle had unwound itself so there was no travel and only about 10% fuel in the bowl!! No wonder it was a bit lean!

i`d check your float level first

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

He did that when he fitted it.

It's all good, the Dr made a house call today. One spark plug was no worky so we changed that, then took it for a run and it's going well. Is a bit rich at idle, I'm sure Sam can sort that out now.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I wish I was in the good Dr's house call range

does Kev have a little black medicine bag full of tricks?

Minis going great now...power increase has been phenomenal!
Increased the idle jets for a better idle and easier take offs...however I still have one issue!
It's happened twice now..if I coast down hill in 3rd gear or so, when I pull up (there's a stop sign as the bottom) it sticks on about 3500 RPM, until I take off.
Anyone had any similar issues? Possibly flooding as I go down hill?
Not a big deal just feel a bit strange sitting at a stop sign making a racket!

Maybe the Weber `cold starting enrichment device' is letting fuel through. This is a known issue with old Webers, so some people plug the circuit off (read that Weber book you have).
Dunno history of your carb, just sayin'.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Could it be the throttle linkage sticking? Is the return spring strong enough or catching somewhere?

Does it happen at any other time - ie on level ground?

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