Old Outlaw

I have a 2016 Massimo 500 SXS and it has been a beast. I have loaded it with brush, firewood, dirt, gravel, rocks (big rocks) and it has always been a reliable, powerful piece of equipment. One hell of a tool. I have replaced the battery once and the fuel injector. If I went out there right now, it would start, run, and deliver. I cannot speak to others who have either had or have not had different experiences but as for me, I like it. 

Mine did the same thing and I changed out the injector. (easy) It now runs better than ever.

I've seen them on eBay from time to time.

Somewhere, sometime, I remember a video of a guy who reset the ECM on his Massimo 500 after changing out the injector, adding a fuel filter, and some other stuff.??? He did it by starting the machine and then going full throttle while in neutral for X# of seconds. Anyone know this process exactly or point me to the video?

Myself.  I have had mine about a year and will probably keep it.  I work it mostly around my place and don't do any recreational driving in the hills or what have you.  I really like mine.  It serves my purpose.

Yup, welcome to the club.  I have a unit very similar to yours and you are correct on both points.  These units ARE noisy and seem to be a little under powered however, the 500 has ample torque in low gear to master most situations.  I've heard others say they had to winch themselves up steep inclines that were long.  Definition of long???? I have never had to do this but then I don't travel 20 miles up into the mountains.  I can't speak to the muffler thing as I have never tried anything of this sort but it does stand to reason that it would cut some of the much needed power from the small 500 cc engine.  As for the tire replacement, smaller diameter tires equal lower overall gear ratio therefore increasing the effective power of the engine.  There will be a slight deficit in top end but a gain in low end although slight.  There is a performance chip available for this engine that costs about $250 that fools the processor into believing the air entering  the engine is actually colder than it is, therefore increasing the fuel flow slightly and so the power of the engine.  Does it work?  I don't know.  I haven't been able to find anyone who has used one of them.  All of that being said, rather than go through the expense and effort of changing wheels and tires, adding the silencer, and  trying to soup up the engine to get more power, trade it for a bigger unit.  I'm faced with the same dilemma.  Good luck.

Any Progress?

Has anyone tried the "Dyno Boost Module" ?  I would like to get a little more power from my Massimo 500.  Input?  Parts suppliers?  

Has anyone tried the "Dyno Boost Module" ?  I would like to get a little more power from my Massimo 500.  Input?  Parts suppliers?  

So, just wondering how your search for parts is gong.  Have you come up with anything new?  Did you try the performance chip?  The air filter?  Any news?