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Discussion Starter · #1 · (Edited)
Hi Guys,

I've recently made a lot of headway with this but I still have some issues I am going to try to be as thorough as possible here so I can get some in sight into possible problems.

Car: 1986 Italian Alfa Romeo Spider S3 2.0L Veloce
Carburettors: Dellorto DHLA 40H - Not original with vehicle (tags are 5336A and 5338P - think these were off a 2.0L GTV)

I had a lot of problems as explained below but I will explain jetting first, NEW is in brackets.

Main Jet: 148 (150)
Idle: 57 (58)
Cold Start Emulsion: 7482.3
Main Emulsion: 7772.11
Air corrector 210

Sparks: NGK B7ES

When I first installed these carbs would get a nosedive at 2000rpm, this problem was smoothed out by changing trumpets to orginal air box - however there was and still is a distinct lack of power. The acceleration is still a bit lumpy perhaps marginally better with the addition of new new jets.

If I am in 4th or 5th gear anything from 1000 - 2000rpm forget about it, I have to press the throttle quite far down just to maintain the same RPM. 2000RPM seems like a real black spot when the engine is under load.

The accelerator pump is probably not right either but that is almost a separate discussion - because i'm more concentrating on gradual opening of the throttle here. With regards to this, if I press the throttle suddenly it will hesitate for a second before picking up speed gradually.

2000-2500 acceleration feels very heavy, indeed it almost always does until your foot is presses right down. I am starting to believe this could be something other than jetting now or it could be Main Emulsion - but I thought 7772.11 was perfectly within range of 2L engines. Timing has been checked and is OK. Engine was recently rebuilt, head skimmed and chain timing done too.

Carbs have been balance with a synchrometer.

Any advice I will be grateful. Thanks
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