hi guys

have what i believe to be a weber dfv.

 

had it going ok, but now its developed an issue where if you rev it, it will rev then the motor will stall when the revs settle. you can get it to idle by fiddling with the throttle, but then once you rev it again it will no doubt stall.

 

any ideas?

Sounds like a vacuum leak. When the throttle butterfly closes after a rev, the vacuum beneath the carb increases, which in turn draws fuel through the idle circuit.

If you have a vacuum leak, the manifold vacuum is too low at idle to draw on the idle circuit and she stalls.

Edited August 12, 201214 yr by GJM85

i checked for that with a can of degreaser and didnt find anything, but i'll grab a can of carby cleaner and double check tonight mate

Other ones to look at would be worn throttle shafts or worn throttle linkages holding the throttle plate open or not..

 

I've had it where it idles when you release the throtle slowly and it settles in one place, but if you drop the throttle off quickly it reverts to a slightly different place and kills the idle.

definately not a vac leak.

 

yeh altezza that sounds like my issue.

mate has a dgv i might try my hand at rebuilding. gotta get this thing reliable again its doing my head in.

chucked the old carb back on. its pretty amazing how much they choke the 4k up. better to be choked and running though i guess

chucked the old carb back on. its pretty amazing how much they choke the 4k up.

 

Ah- that's good to know. It means the Weber definately does make a difference. Like my SUs, guys often do carbs/cam/exhaust all at once and I wouldn't know what just changing the carb did.

 

Post up the solution when you find it-