Hi out there!
My engine is the Surpass 120 MK I. It has not run more than approx 25 hours all together, but it's been lying about for several years after a crash until a got my 1/4-scale CUB finished last year. After consulting this forum a year ago I have run the engine several hours, and flown the model some, but I can't get it to perform reliably. I've had a pump problem no doubt about it. There is a gear within the pump and because there was a slight instability there, the taps and notches (or whatever you call them) could suddenly start catching. This was the reason, I believe, why the engine sometimes overheated. There were no spare parts available and in Sweden, where I live. I could neither get hold of a MK I nor MK II pump for replacement.
So, I decided to convert the engine to a non-pump. I simply got a new back-plate and grinded off the extension on the .....(what the heck is "vevaxel" in English? The part that holds the piston in one end and the prop in the other)..You know. After opening up the fuel needle 7½ turns it runs beautifully between idle and half throttle. I've realized the obvious fact that you must replace the carburetor as well. But, then you must also replace the inlet manifold. But the diameter of the manifold on my pumped engine is 12mm and on the non pumped engine only 10mm, roughly. So there will be a mismatch when it comes to where the manifold enters the crankcase. So we've got a problem here.
As I recall it, I got an e-mail from somebody "over there" after my prior contact with the forum. This someone claimed there was a conversion kit when you wanted to do this. But at the time I thought I'd already solved the problem so I gave it no notice. Now, is there such a thing as a "conversion kit", or how do I go from here? Please just don't give me the advise to sell my engine which is what I got from the OS "expert" in my country.

Looking forward to get some feed-back

Peter Evers