The OKO is a copy of a Keihin, I bought  a cheap OKO off ebay and it was rubbish. Apparently the genuine OKO is good , so I assume you should buy one off a dealer rather than ebay. Keihins are 28mm and you can buy OKOs that are 30mm but they are bored oval to obtain the larger size, the width is 28 but the height is increased to 30mm

I do Get them off the dealer.

 

 

On 5/31/2017 at 0:26 PM, bondy said:

I have a oko on my 199A runs sweet

 

 

What size OKO ?

i want to fit one to my 199A but have been told sizes to put on are 26, 28 and 30 so far. Can anyone confirm a size that works nice?

All the current new bikes use 28 keihins which is what is on my 199A and it works fine. They are a very clean crisp running carb that works well even if the jetting is slightly off. The 199A came with a 28 Bing so I would stick with 28

markg, I have three Sherpas, a M159, M199 and my M199B with a M151 engine in it. I have 28mm OKOs on all of them and they all work great. I had to richen a couple up on the needle and lean the other one off one notch on the needle. You also need a new carb to barrel rubber. The In Motion ones for a Mikuni work very well and are the correct size. Graham.

Just put the Mikuni 26 on from Steve at Motocarb in Liverpool and it worked fine on the settings it came with.

Also supplied were a selection of jets either side size wise of the fitted ones for fine tuning.

Im ?.

Its all personal choice at the end of the day.

Going to stop fannying around with it , now it's had all its faults sorted and ride the thing.

i use the 26mm and a qiet a few i know use 26mm runs very nice no issus straight from the box at a fraction off the cost just got 1 for my mate.