Start 5 of the Moto Guzzi Calisportia.

Start 5 of the Calisportia hotrod.
When I ran the bike during start 4, it was noticeable that the revs were a bit slow to drop.
I was aware of it at the time and and I was sure it was only because I was running the lightest possible springs in the carbs (Dellorto part 8550) which were fine before with the old small valve, low compression, 844 motor, but that they were not strong enough with the MUCH more powerful V11s LeMans motor.
later that evening I fitted some medium strength springs (Dellorto 8532) and with the motor off the difference was immediately obvious but I had to wait for new rocker cover gaskets to arrive in the post before I could test it with the suction from the motor.
For anyone who isn't already aware but interested, the vacuum from the motor that pulls the mixture into the combustion chamber, also pulls the carb slides forward against the inside of the carb body and springs need to be strong enough to overcome that suck as well as any friction in cables and the twist grip.
That is why people used to CV carbs always moan about how heavy the throttle is on old Guzzis. CV carbs don't need heavy springs as the cable only opens a butterfly and usually has a closing cable too, then the vacuum lifts the slides and when you close the butterfly there is no vacuum acting on the slides from the inlet port to pull on the slide forwards causing resistance to the slide closing. (If you doubt this is true, have a look at your pfh or phm slides and you will see the wear is on the front facing side).
Likewise FCRs can have very light springs because of the trolley like slides (ingeniously the slides in FCRs run on tiny wheels so can't get stuck against the carb body) AND FCRs usually run with closing cables too, whereas poor old Dellortos have no wheels and no closing cables so have to rely on heavy springs to overcome the engine pulling the slides against the inside of the carb, the only possible slight fix is adding weight to the slides instead of heavier springs, I've heard of people putting lead in the slides!
Anyway, that's the issue.
While waiting for the postman, I thought I may as well check and adjust the rocker gaps, they were slightly big so I set them to a bigger than 'book' 0.15 and 0.2, (The factory book recommends 0.1 and 0.15 for this motor but as I'm not running an oil cooler I thought it made sense to go a bit bigger).
The postie came and I fitted the new gaskets and adaptor plates with my old round covers and I am absolutely delighted with the look.
Then I got to fire it up with the medium springs to test.
As you can hear the rev's now drop smartly and it was as I suspected just the springs, no air leaks or anything else untoward.
The carbs are still only balanced by ear, and I think it already sounds fantastic, rev's pick up and drop SO quickly.
Its amazing that such a slight difference in spring has such a dramatic effect, the light ones are 1.1mm wire and 125mm long, and the medium springs are 1.2mm wire and 132mm long. To me that doesn't sound like much but you can really feel the difference.
Looks like I'll soon have my old Popeye arms back (10 spring sport clutch too).