Ironhead Branch backing plate

[ricusa]

I'm looking for a Branch flowmatics backing plate for a Mikuni VM38 carb. I've seen them on eBay but they all (at least now) state for Lectron or 40-44 Mikuni or just for a Harley Shovelhead. Can't get more info from the sellers. I know the carb openings are different diameters between the 44 & 38 but how about a adapter? The Shovel one looks like it's smaller dia, and closer to what I want. But?? Any incite here?

[bustert]

have that on my 74ch and had the same on the 74fx. same thing.
the size pertain to the venturi and not to the inlet opening. if in doubt, google the carb in question to get specifics. adapters, sure, anything is possible.

[boonoorong]

Gidday ricusa, Apologies for the slow reply, I’ve been working away from home so was unable to take images.

I’ve been down the same path and hopefully the following will give you more information.

Yes, there are BRANCH Air Filter Backing Plates uniquely designed for the VM38 Mikuni (the Backing Plate port fits into the Mikuni venturi) and they have the words “Branch Flowmetric” cast into the backing plate.





The VM38 BRANCH Backing Plates do pop up on eBay from time to time as I sourced mine from eBay USA.

I’ve also attached an image of a VM44 Mikuni with Branch Backing Plate to help differentiate the VM38 from the VM44 design - for the VM44, the Branch Backing Plate fits over the OD of the venturi and has “Branch Flometrics No44” cast into the backing plate.







FYI, I’ve not identified any differences between BRANCH Inlet Manifolds for the VM38 and VM44 Mikuni’s, ie. all the BRANCH manifolds I’ve seen appear to be ported for the VM44, ie. 52mm OD. I’m not saying the VM38 type does not exist, I just haven’t seen one with port diameters that more nearly match the VM38, ie. 43mm OD.

Not sure how steadfast you are with finding a VM38 Branch kit but after initially heading down the path of the Branch products, I’ve since purchased a K&N Air Filter Assembly (P/No ML-085B) that rubber mounts directly to the VM38 Mikuni and allows fitment of a round HD cover. I’ll still use a support for the carby/filter assembly, but the weight is significantly reduced with the K&N design compared to the Branch Backing Plate with Original Air Filter, blah-de-blah.







Opeitelps - Muzz

[sungod]

Originally Posted by bustert

have that on my 74ch and had the same on the 74fx. same thing.
the size pertain to the venturi and not to the inlet opening. if in doubt, google the carb in question to get specifics. adapters, sure, anything is possible.

Ebay seller Legendsmc has the Branch adapter.
Description says the 38 fits 40 and since the 40 and 44 have the same dimension it fit should fit the 44 also.

[boonoorong]

ricusa, to mount my Mikuni VM38 (43mm OD) to the engine I intend to use a BRANCH manifold (52mm OD) but am yet to source an adapter.



Another option I explored was to use a HD inlet manifold (P/No 27021-71A) with a flange to spigot adapter (P/No VM36-200K).
Note : I have not sourced the adapter, only researched.






The following extract from Mikuni for the VMseries provides the critical dimensions of the carb so should assist you to source the correct size mountings and adapters, and I can also confirm that the INLET and OUTLET OD (outside dimension) of the VM38 differs from the VM44 (I have both carbs and their actual dimensions concur with the table), so take care and choose wisely.



In your search for an adapter you're also likely to see references to the Mikuni TMseries, so I've attached a table with their dimensions :



Once again, opeitelps - Muzz

[boonoorong]

ricusa, there is a BRANCH Backing Plate to suit the Mikuni VM38 currently as a "BUY IT NOW" on eBay. Enter the eBay item number: 295639316762 and it should pop up.

[IronMick]

Originally Posted by boonoorong

ricusa, there is a BRANCH Backing Plate to suit the Mikuni VM38 currently as a "BUY IT NOW" on eBay. Enter the eBay item number: 295639316762 and it should pop up.

Get it while you can! These are the cat's meows to mount your Mikuni VM38-9