problems with dellorto twin 40s

[dan23]

i cant get my twin 40s to run my engine i ve got the correct jets from euro carb but it wont idle

how turns in /out should the idle screws have
its running a 1.4 bottom 1.3 head an 1.4 cam

http://img364.imageshack.us/img364/379/dsc00011li0.th.jpg (http://img364.imageshack.us/my.php?image=dsc00011li0.jpg)

[Adam]

Silly question but, is the idle turned up enough?

Will it stay running if you hold the throttle

[Stuart]

take it to an RR for a setup :D

[dan23]

before when i put them on it would stay running with throttle held open but was jetted for 1.3 . i replaced the jets as my engine is 1.4 now it run even if thriottle is held open

[dan23]

surely i should be able to get to run (badly) before its taken for rr setup so they will have something to work with
not just a heap that wont start

[Adam]

What jets/chokes are fitted?

I could find my old jet/choke sizes that my t40d 1400 had, but i ran webers so there iirelevant.

[dan23]

i cant remember off top of my head but i told euro carb the set up an they gave me the correct bits

[tom_beverley]

I will have a look at mine tonight if I remember and note the jet sizes down for you.

IIRC when I got mine they were jetted for a 1600 though, but I ran them on my B+ 1400 no problems. If nothing else it will give you a guide :p

[meritlover]

is the ign timing correct? you able to achieve a perfectly smooth idle without taking it to the Dyno.
what is your fuel pressure?

[dan23]

i dont know the fuel pressure i using a new mech pump an a regulator that came with the carbs

as for timing the timing pointer on the block semed to be missing so we used a wd40 straw on the hole so it could be a tooth out

but after all this was done it ran with the old jets with the throttle held open (the jets were for a 1.3 engine)

sincereplacing the jets its not run on further inspection the idle screws were turned quite alot i ve turned the idle up but still no joy

maybe i should put the old jets back in with the idle up an see what happens

[dan23]

this is one of the old jets you can see it has a rubber o ring seal on it

the new ones dont could this be the problem ?

http://img76.imageshack.us/img76/884/image000zw7.th.jpg (http://img76.imageshack.us/my.php?image=image000zw7.jpg)

[Adam]

Yes

[dan23]

so i need to order aset of those rubber o rings or can they be taken off an swapped over

what do they do ?

[Adam]

Try taking them off and swapping them over.
Looking at them, id say they stop fuel leaking out/air leaking into the idle needle jet

[mad-driver]

God haven't been on here for a while!...

Anyway, might be worth checking what sort of carbs they are. If you're lucky enough to have the emission type dellortos they require totally different jetting to normal carbs. I found this out when i put jets in mine, that should have worked fine, but wouldn't idle whatsoever...

Just an example is that normal carbs (non-emission type) may need a 40 idle jet, whereas emission type carbs like i had, would only run if you upped the jet size to 55/60.

Just a thought, though it could be as simple as Ad says... with the lack of o'rings sealing the jet itself.

[meritlover]

get it running close to idle on the throttle. cup your hands over the trumpets and if the idle steadies then its running too lean. if its worse then its too rich.