Somehow, I got it into my head that the jets on the 900ss were back to factory spec. Might have been because I was working on the Hurricane at the same time? A few weeks ago, I decided to tear down the carbs again because it was still smelling a bit rich at idle. What did I find you ask? Well, jets, jets that were not at stock config. The main was 127.5, and the pilot was a 40. The Ducati Bible states that the main should be a 140, with a 42.5 pilot. So, I did what the good book says and fattened it up.
With the carbs back on, and the battle with the throttle cables complete (I still need to get a new throttle cable, despite all my effort, I cannot get the throttle to snap closed), I warmed up the bike. I had the mixtures set at 3.5 turns out and it started without issue. Took it out for spin.
I never understood all the talk about the 900ss being a wild machine, even with Hunter S. Thompson's tail of the sausage creature, the bike seemed mild. Fun, but a bit mild. I thought maybe it was because the big twin 1200cc Buell Ulysses set such a high expectation. While it's not match for the XB, the 900ss now feels like I expected it to feel. The front end feels lighter on throttle, where I used to have a flat spot at 6k-7k, it now pulls hard all the way through! Yeah baby!
The ability to tune the mixture screws by ear is not something I have gained, I just can't tell the difference enough to know if it's in the sweet spot. So, I did what I did before and tuned them to allow the bike to roughly idle one cylinder. The horizontal still requires more turns out than the vertical, and I think it's because some chucklehead widened the ports on the throats, and they are not equal size.
So...that is probably the root cause of the mixture discrepancy. Now I am faced with a choice. Do I live with it? Do I get a new carb body and move all the bits over? Or...do I save my pennies and put a set of FCR39s on it and open myself to a whole new world of jetting adventures? ( I really want the FCRs.)
Stay safe out there!
