Hi Peter, it really depends on how far you wish to go with the service. The carbies are no more difficult to service than any other quantum or tecumseh unit. The main jet is held is screwed into the main venturi and the emusion tube{which generally drops out after the jet is removed}has a small series of holes in it just like a honda and these require careful cleaning when dismantling the carb. There are no orings on the emulsion tube, unlike the tecumseh carbs. The key to easy starting with these is to ensure full choke is engaged at full throttle. After removing the air filter the easiest way to get the carb off is to remove the 2 studs that go into the block to enable you to twist and manouvre the carb to get the linkages off.
As for valve adjustment, unlike the side valve briggs and tecumseh's, clearances are fully adjustable but literature on specs is hard to come by on these. My guess would be the same clearances as a GXV120 or about 0.1mm on both inlet and exhaust (i may stand to be corrected here).
My experience with these motors is that they are quite good for what they are and generally have loads of torque, but the inferior quality of starters, throttle and governor assemblies is what generally lets them down.
Another issue with these in particular is the air filter. They are a dry paper element and if they get oil wet they generally cause the engine to chugg and cough. Admittedly they are available from Kmart for $8 as they are the same as the "Gardeners Choice" which Kmart sell.
Having said all that, take it for a test run, if it runs as it should, do the minimum and move it along.
