3.5 SU Fast Idle Setup
Posted: Wed Nov 29, 2023 1:05 pm
Hi,
I’m looking for some advice setting the fast idle on my 3.5 running twin SU HIF6s.
My engine will start with the choke out after a few turns but it is lumpy and poppy and does not have a smooth fast idle.
With the choke pulled out, I can confirm that the fast idle quadrants in both carbs are maxed out (I.e as rich as they can get) but I am not sure what my idle should be when fast.
I have tried to match the butterfly openings on both carbs with the choke partially open, but it goes off the scale on my meter with the choke fully out. I think the carbs need to be drawing a little more air with the choke out.
Is it assumed that the choke should always be out as far as possible for a cold start? Is there a nifty way to set this?
Thanks,
-Tom
I’m looking for some advice setting the fast idle on my 3.5 running twin SU HIF6s.
My engine will start with the choke out after a few turns but it is lumpy and poppy and does not have a smooth fast idle.
With the choke pulled out, I can confirm that the fast idle quadrants in both carbs are maxed out (I.e as rich as they can get) but I am not sure what my idle should be when fast.
I have tried to match the butterfly openings on both carbs with the choke partially open, but it goes off the scale on my meter with the choke fully out. I think the carbs need to be drawing a little more air with the choke out.
Is it assumed that the choke should always be out as far as possible for a cold start? Is there a nifty way to set this?
Thanks,
-Tom