poorly merry tiller (needs transplant surgery)

hi, i have an old merry tiller, 3HP briggs & stratton, the engine is past its best, the carb has a mind of its own, i set it up it runs all day the following day it decides its not playing,  now one of the carb bolts has decided to come out with the threads from the block, so to get to the point,rather than struggle on with the old carb & helicoiling the block i think its time for a new engine, can anyone recommend a replacement that will be pretty straight forward to fit and reliable? i have heard honda engines work fine, so i bought a honda powered generator that was running fine with no output 5.5HP so far so good then i removed the alternator and there was a tappered shaft, (not so good) so rather than weld on the pulley i will look for a new alternator and have a good generator, but this still leaves me without an engine for old smokey,any advice please on the right one for the job Regards Paul.

New Merry Tillers, which are almost identical to the old 3hp Majors, use the 5.5hp Honda engine but I personally find that all bigger engines than the 3hp unit make the machine harder to manoeuvre at the row ends. If you have a large plot with long rows the extra grunt of  a bigger engine may be worth it, but for smaller beds the 3hp B & S engine is best.

Regards, Richard

I put a 6.5 HP brand new Honda G220 engine (£90 collected)  on my Merry Tiller, holy moly.  You could take up a tarmac drive with it now, even on low revs. The power is awesome, its totally unstoppable, will easy turn three pairs of tines , if not for the fact a Merry Tiller with 3 pairs of tines on needs two people to hold it back.