Dellorto acceleration issue.

[dougal9887]

I've just put in the 60 mile 1st stage of running in.
Jetting to QED spec for the 420 cams seems pretty much spot on. Plugs are clean. Steady acceleration is smooth but foot to the floor acceleration produces a hesitation. Pump jets are still standard big valve spec. Carbs are rebuilt. Diaphragms are new. All 4 barrels squirt although quantity not measured. Actuating rod not altered from new.
Before I try a larger pump jet, I wondered about the diaphram springs which were not changed. Anyone found a necessity to change these?
Otherwise I suppose I should attempt to measure the quantity squirted. The distance squirted was certainly not the metre suggested in the Vizard book, maybe half that.
The other symptom that makes me wonder about quantity being squirted is that the engine doesn't start on the customary 2 pushes of the pedal but does start straight away with the choke out.
Anyones experience with such an issue appreciated.
Dougal.

[terryp]

Have a look at this.
lotus-carbs-f40/difficult-cold-starting-dellortos-130-t15934-15.html

When I had my +2 I changed from vertical to horizontal jets and the difference was amazing

Terry

[Europatc]

Hello Dougal, I have to use choke on my Elan and Europa. The Elan is going in to be set up next week on a rolling road following an engine rebuild so it will be interested to see if there is any difference. Both cars run on Dellorto's
all the best
Stuart

[dougal9887]

Thanks for the replies.
I found I had some larger pump jets in my spares so that was easy to try and indeed fixed the hesitation.
Interestingly the ones I removed were forward squirters and the replacements are downwards. I haven't had time to do all the starting permutations yet but will report back.
Dougal.