Emissions and Twin carb tuning

Tuning day for Brian and Peter
Brian's 80 era mini had a nice surprise, a Swifttune built 998 motor.
Peter's MK1 S was fun to tune as it had twin carbs.
Here is a chance to see what goes into a Tuning Session as well as before and after data from the gas analyzer.
I found a worn needle and carb, restrictive air filter, bad distributor advance, and had to do a custom SU carb needle profiling.

[@GTE_Channel]

Keep the videos coming! A great addition to AC's videos and really motivating!

[@darrensrestorations991]

Thanks! Will do!

[@mmurphy1487]

Hi Darren,
During the tuning of the swiftune 998 mini you explained that the carburetor was not giving a stable idle when trying to adjust the idle mixture. Can you explain what you did with the brake cleaner to come to the conclusion to replace the carb? I am having a similar issue ie unstable lambda readings at idle. Keep up the good work with keeping mini’s on the road, I enjoy your videos.
Matt

[@darrensrestorations991]

Hi Matt, the non-chlorinated brake cleaner I use is flammable. When I spray into places that have vacuum leaks such as the throttle shafts or intake manifold, it gets sucked into the intake and burned with the air/fuel mixture. This will show on the lambda gauge as a rich reading. It also blocks up the air leak and the mixture reads richer. It's a great way of diagnosing any vacuum leaks.

[@mmurphy1487]

Great Darren, thanks very much for the explanation, I will try it out on my carb and intake.
Matt

[@jonesboy2004]

Great video. With the twin carbs what colour spring was it running and what oil did you settle on to pull enrichment back? Thanks

[@darrensrestorations991]

I think it was a yellow spring and 10w30oil.
Thanks for watching

[@jonesboy2004]

@darrensrestorations991 thanks Darren, am I better off with a leaner needle and thicker oil or richer needle and thinner oil for performance to get the correct 0.85 on the gauge during acceleration? Cheers