Twin 40 Problem - PLEASE help :(

[mikeoxford]

ill have a pair of weber twin 40s and manfiold to suit a 1.3 for sale soon - there considerably pi$$in me off. i cant get to velos for them to sort it out as its too far, and theres no where local to sort it for me.

one good sellingpoint - there off an original nova sport 8) :lol:

ive got some mad overfuelling problem at idle or the middle progression circuit i aint sure - so im assuming there jetted wrong?

although they worked alright / FINE with 28mm chokes, all ive done since is fitted 30mm chokes and short ram pipes, have i done anything wrong?

could i have put anything back together wrong??

under acceleration and everything there fine.

:evil: :evil: :evil:

close to tears - time effort and money, and lack of results is VERY disheartening, ive already staretd searching autotrader in the metro gta section :lol: :oops:

[mikeoxford]

i may try my old 28mm chokes - c what the crack is with those in, is that a plan???

[Jim]

if you have changesd something and it doesn't work, change back to how it was and take it one step at a time. If you don't feel that confident, then I suggest you get to a specialist like Velos.

Jim

[mikeoxford]

thinkin about it i put money on the fact my jets are not compatible with me changing chokes

velos said it was jetted original as a nova sport would be and also with restrictive 28mm chokes that they came with, so i reckon ill change the chokes back 2moro and see what effect it has if any :?

fingers crossed

any other ideas?

[CP]

Umm, its difficult to diagnose without looking at them.

PM me your e- mail address and I'll attempt to send you part of a scanned Lotus Cortina workshop manual which shows how they work and whats what plus how to do the basic set-up- sorry its a bit hazy.
I would take out a set of jets in one carb and find out what they are - the size is printed on the jet tips. If you phone this no. 01223 207217 ( Wilshires Garage nr Cambridge) and ask for Peter Baldwin he may be able to tell you if you are about ball park with the jet sizes you have for what you have done to your engine. He's a good bloke to talk to in anyway

In any event ( unless you are MC) or endlessly patient and prepared to keep swapping a range of jets about, you will need to get on a rolling road. They can set the jetting accurately with CO2 emissions testing plus swing the dizzy to time in the sparks. This will also find any little problems that you maybe unaware of like a shot lead or damaged plug. The above garage will do it - he also has jets. It will almost certainly be a question of getting them set up and the rr is the place to do

[mikeoxford]

cheers CP

what im going to do tomorow is change back to the 28mm chokes, and see if it drives anything like before, if it DOES then im gonna go easy on her, as shes running rich, and then get to velos when dan goes and swap over the chokes there.........

i THINK it is a jetting problem.

[rob.slader]

Mike, hope you get the problem sorted, sounds like youre having a hard time from it?

[mikeoxford]

Mike, hope you get the problem sorted, sounds like youre having a hard time from it?

erm a lil.

i found a load of stuff on the net and i think its just a jetting problem rob m8.

i say this because even with 28mm chokes, occasionally - about once a day, if i have the throttle just wrong, and certain amount of revs, it spits fuel from the carb and makes like a tractor noise - it did it just as i was pulling away from MK! and it had been SWEET all day prior :( felt like an idiot!

erm, basically

now ive changed to 30mm choeks, it does the tractor noise / spitting up until 3000 revs when it clears itself, i guess the main circuit kicks in then and thats jetted up well enough.

SO

28mm chokes go back on tomorow, so i can limp to velos, and whack the 30mm chokes on, and let them sort it!

[mikeoxford]

fingers crossed yeah? :oops:

[rob.slader]

Yeah fingers crossed, you do tend to get them spitting occassionally though, not sure how often yours does it. Mine used to do it when it was cold in the morning first thing on startup, like a popping noise. I had it really bad when I first fitted them before having them set up at the rolling road. The carb balancing has a lot do do with the popping too, don't think it will be the choke sizes. Best get it set up properly as they are pretty hard to get spot on. I would make sure your balance screw in the middle of the carbs isn't loose too, I had that problem and they came out of balance very easily. I just tightened the mechanism right up and that solved it. Good luck mate!