Si 24/24 Carb mixture screw???

[fredperrybruce]

Hi all,,,, I'm sure I know the answer but need someone else's view on this also

My friend has just brought a brand new Dellorto si 24/24 carb but when installing into he's carb box he couldn't get the long mixture screw in due to the starter motor being in the way!!!

So he had a bright idea of swapping the mixture screw over for the older type one which is much smaller,, he managed to screw the thing into the carb but cannot for love or money get the thing running right....

I was sure the to screws have different threads and would f**k the threads in the carb up?? AM I RIGHT?? could this be a costly mistake??


Cheers guys

[bryno]

Yes the screws are different threads, later long one is finer iirc.

If he has effectively recut the thread with the wrong screw and it has threaded well enough to stop air leaking through the threads no reason why it won't work, unless of course the taper on the 2 types is completely different, but even then it should still work just may not be the usual 2 1/2 turns.

[vespasco]

You're right
The tapers are different
As are the threads
It could be a costly mistake or you might be lucky
You should try the correct mix screw for the carb.
Loctite may help if its a sloppy/loose fit. You may have to get rid of the spring too?!

[mickymidas]

I'm sure there is a thread (no pun intended) on here somewhere about an easier way to fit /adjust a mixture screw with a starter motor fitted,....and iirc there was a pic of a re-worked tool made to fit

[henri]

oops , as the above , an micky if ya can find that thread i'd appreciate it ,as its a pig of a job gettin them started on the thread ,H