Alfa Pages

[fluffyduff]

Guys just wondering if anyone can shed some light on a problem Ive been having for a little while.

The vacuum advance unit off my 1350 engine got *ahem* damaged while i was swapping the engines. I swapped the unit off the 1490 and mated it with the dizzy from the 1350. Happy days.

But since then Ive developed a bad miss under full throttle. Ive ruled out everything except this vacuum unit and the carbs (which seems to be ok as it idles and holds revs smoothly. Ill check these tomorrow anyway but im wondering if there's a difference between the vacuum units that could be adding to the problem.

the original unit has "110 3151" stamped on the arm that fits inside the dizzy and the one off the 1490 engine has "110 2295"

Anyone know the significance of these numbers?

[Admin]

Hi

Think there were a couple of different vacuum advance curves in the old series 1 manual. However I would not think that the difference between the 1300 and the 1500 would be enough for a severe misfire.

It would be worth checking with a timing light that the timing does actually advance / retard as the revs go up.

All the best

Keith
_________________
I owe, I owe, its off to work we go.
Bimota Forum
Stafford Christmas Lights

[fluffyduff]

the timing is advancing but not far enough i think. at 4500rpm its all over the place but if you hold the vacuum on it manually its fine.

I'm gonna stick a new one in as the one I'm using is an unknown quantity and that other engine sat in a corner for a long time before i bought it.

Interesting that there were two different curves on the s1. There's about 10 years between the two engines so maybe something changed in that time.

Thanks for the heads up

[Admin]