Originally Posted by 00Dan
Still wondering in this. I may need to change carbs and for the price the rotec is an attractive option.
Not an easy change. Rotec now recommends a fuel return line and an air/fuel ratio gauge for setting it up. As mentioned the primer cable, prefilter requirements and linkage changes.
Can't speak to the O-320 size but the O-360 size is about 1.5" shorter in height than the MS carb. I tried one for about 100hrs on my 360 after doing some of the mods Rockett Bob used (1/4" insulator at the sump, 1.5"x 6" dia. plenum adapter on the inlet...Bob used a straight Venturi style adapter, A/F gauge, drilled out a few of the spraybar holes at the WOT end). Never did put in a return line but did not have an issue with hot starting. The engine ran smooth, started and idled great but ran lean at WOT. I got tired of messing with it and changed to the MS. Now have 2 of them gathering dust in the hangar. (Paul gave me a good deal on the second one which was supposed to be the solution...ran worse than the first one - never flew it) Very poor support unless I was spending money. I have read that some people have had better experiences with the O-320 size. I personally know one person that replaced his Rotec radial using the TBI with a carbed Lycoming on his new Hatz Biplane after having 3 engine failures. He also received no support.
My opinion, based on my experience is buyer beware.
Feel free to send a PM if you would like more details.