Mikuni on a Monza

[Blaine.Hale]

Anyone have the jetting they used on a 250 Monza for this VM26?
I ordered the Sudco kit and it got me started and idling well. When I'm off the choke and revving off idle, it is hesitant to rev but eventually does rev pretty well but won't come back down to idle. That tells me there's a lean condition, perhaps? Everyone seems to stick with the 5DP7 needle but what should I be looking to change out here, my air, pilot, or main? I raised the needle to its last slot and that still doesn't seem to be enough fuel off idle to get it into the revs without hesitation. Idle mixture backed all the way out but I don't think that's the issue...since that's just an idle mixture.

I haven't ruled out a sticking advance mechanism but I did completely lube and test that sucker out before putting it back in.
Another thing to add: It revs really well when on choke and comes down to idle instantly. So definitely points to a lean condition when off choke, in my opinion.

[themoudie]

Aye Blain,

For my pennyworth, the

When I'm off the choke and revving off idle, it is hesitant to rev but eventually does rev pretty well but won't come back down to idle. That tells me there's a lean condition, perhaps?

makes me think that the slide is not correct?

Have you read DanC Mikuni settings, albeit on a VM30 fitted to a 350 and a 450 in this thread?: 450_Desmo_carb_Page_3_DanC

Just an update on Mikuni VM 30 jetting.

On 1974 450 Desmo.
Pilot 35, Needle 6F5 on bottom notch, Needle Jet P5, Main 180, Air jet 2.0, Slide 2.5
These settings on this bike are giving nice tan coloured plug readings throughout the rev range. Bike starts easily, idles and revs cleanly at all throttle settings. Maybe not the carb size for maximising power but I'm very happy with everyday ride-ability. At my age power isnt important....!

On 1969 350 Desmo.
Pilot 30, Needle 6F5 on middle notch, Needle Jet P5, Main 160, Air jet 2.0, Slide 2.5
Similarly these settings on this bike are giving nice tan coloured plug readings throughout the rev range. Bike starts easily, idles and revs cleanly at all throttle settings.

Is your slide wildly different?

Hope this helps, Bill