KT250 New VM26 Carb Jetting

[stevemather]

I need to replace my old VM26SC carb on my 75 KT250.
The only available option is a new VM26-8074 from the very helpful Mikuni dealer in Townsville.
The problem is that the KT250 original carb uses non standard Mikuni jetting / needles etc and there is no direct jetting conversion to the new carb.

Has anyone fitted a new VM26-8074 to their KT250, and if so what jetting did you end up with?

[pop]

I recently put a Chinese mikuni copy on to a 175, only needed needle adjustment , it will most likely only need minor adjustment being same size, put it on and see how it runs and go from there.

[David Lahey]

Steve I have only ever run the standard KT carby on my KT, but have run KT250 carbies on my OSSA MAR 250 and my Cota 348.
With the KT carby, the 250cc OSSA is perfect but the 310cc Montesa was slightly lean just above the pilot.
I then bought a new VM26 8074 (with jetting provided by the supplier to suit Cota 348) from the UK for the Cota 348 and could not get it any better than with the KT250 carby, and ended up buying a prejetted 26mm OKO, which was great straight out of the box.
I also bought a new VM26 8074 (with jetting provided by the supplier to suit Bultaco Sherpa T model 198) for my Bultaco M198 (238cc) from the same UK supplier but have not tried it yet.
In case it is useful for you, here are the jetting specs that these VM26 8074 carbies came with:
M198 (240cc piston-port induction trials bike)
main 115
pilot 32.5
needle jet 182 N-8
needle 5F21
slide 2.5
air jet 0.5

Cota 348 (310cc piston-port induction trials bike)
main 130
pilot 35
needle jet 182 N-8
needle 5F21 (I found the bottom groove was best)
slide 2.5 (I found a 2.0 slide was better)
air jet 0.5

[stevemather]

Thanks Dave, every helpful, will get a new vM26 after Christmas rush