Does anyone know how to make a MDS 1.48 transition from idle to full throttle? It has had the carb upgrade and it idles good and has good full throttle but tends to cough and sputter at half throttle and will usually quit, can anyone help?

I just went through this . I messed with pumps , head shims , plugs , tapering low end needle , closing one exhaust tube , larger fuel line , different fuels , 4 different carbs , and different combos of these .

I finally got it to run great today after alot of tinkering . I wound up using a Magnum carb off of a 1.08 . I made two head shims to use until the ones i ordered get here . I am running an O.S. F four stroke plug and a mix of 5% nitro and 18% oil with a 50/50 mix of synthetic and castor .
I am using the Bisson pitts style muffler .

I broke the engine in on the test stand with two gallons of 20% oil and burned another 3 gallons of 18% oil since trying to get it to transition well .

My idle and top end was great with all four carbs but the Magnum was the only one that would transition through mid range with out it looking like i was running smoke . Now it transitions clean and i can hover lower to the ground with out worring too much .

Barry

Ditto the carb switch. I put a carb from a Magnum 1.20 on mine, all the problems went away.