What size carb have you all used

[HMBAtrail]

350 wide case race bike. 40/36mm valves. High compression Omega race piston. That whomper of a 277 profile cam. Building a custom exhaust but will be 1.5" ID pipe with a 16" Cone Performance Max Performance reverse meg.

So, armed with that info, what have you folks seen for carb size? Specifically Mikuni (although I'm not married to a Mik but I have a ton of Mik jets from other bikes so . . .) I've heard folks using a VM32, VM34 and even a VM36. Before I wander down a dead end I thought I'd query you good folks to get guidance.

[double diamond]

Eric Pritchard, who ran 250 and 350 Ducatis in AHRMA some time ago, related the following information on carbs he used:

350: Mikuni "round slide" 38mm, MJ: 270, PJ: 45, NJ:166 P-8, needle: 6DH3, middle clip, slide: 2.5, manifold tapers from 38mm to 34mm

the 250 used a 36mm Mikuni, same jetting except for a 250 MJ, manifold tapers from 34 to 32mm.

Matt

[Eldert]

the smallest carb i use on a 350 is 38 mm . on my own 350 i use a 41.5 mm Malossi carb .
i use a bigger 42 mm inlet valve with a 7 mm valve stem .

Steve Mahanes swears by a VM 44 Mikuni . he also uses very large valves . i think he gets some tuning advice from Reno L

Eldert

[LaceyDucati]

I would agree with Eldert, 38mm smallest. I use a 38mm Amal Mk2 smoothbore on 350's and 450's. In the past I tried 36mm's but nothing was better. However Amal MK2 smoothbore carbs flow more air than std carbs so I think you would need at least a 38mm Mikuni. Amal smoothbores are no longer made. They give good performance in good condition and are simplistic, however Amal carbs are not generally well made and needle jets wear out.

I have customers who have used 38mm and 40mm delorto's, 38mm Mikunis and Gardeners, all with decent results. However I just stick to what I know and It seems to work

Nigel

[HMBAtrail]

Thanks for the great info gentlemen! And Nigel, thanks for pulling together the order for engine parts.

All my best,
Tim O'Donnell