Another update,

I think something was wrong with my WT 456, it will not adjust. I had around a WA120 and I said to give it a try. What I did, I took the spring for pump from the 456 and without making a hole in the pump cover, I just stik it under the membrane, close the carby and span the motor. I did not prime ...nothing. When I span the motor I was able to see how the fuel got to the carb and engine started. It holds a real nice Idle around 1800 , it can go down to 1550-1600 but a bit shaky.On high I got top RPM with Evolution 16/6 8600 RPM. Transition is not that smooth, I have to go progresive on acceleration. If I ritchen the low it does better on mid range. And the setup instructions from Walbro for adjustment work like the book say.Why the Wt 456 did not want to ?
Any way I ordered on ebay another 456 to try it out again. ThisWA 120 has a 7.89 ventury if I remember right. How this...ventury afects the engine. How would you know what to get. does the wentury influence the fuel consumption.
It is any other Walbro carb there with acceleration pump close to this 6.5- 8 mm ventury?

Thank you
Adrian