I bought this 2003 Grizzly knowing it needed work so I was prepared to work on it. It has 452 hrs. and the guy said it needed an axle and didnt run to good. I go and look at it and see that it was not taken very good care of but bought it anyway.( price seemed right $2400). It started and was quiet (no engine noise and no smoke). He also stated that it sat for over a year so the gas was bad. I get it home and notice the carb. is leaking gas the float is stuck. I pull the carb off and see that someone has dug into it before. I had to replace the needle and seat for the float. I cleaned it up and put it back on. Now it will start and idle fine but as soon as I give it any throttle it will backfire through the intake. It will start right back up but I couldnt get it to take any throttle. I then took the upper part of the carburetor apart and noticed the diaphragm had a very small hole in it. My question is can this be the problem? I dont want to keep putting money into this carburetor and not fix the problem. I can get a new carb for $286 but if I can fix this one I can save about $250. The rest of the carb. looks to be O.K but as I said I can tell someone has been in there before me so I dont know if they screwed up a passage with a piece of wire or something. Thanks in advance for any help you may have.

 

I don't know about the diaphragm causing you any trouble, but it could be getting air through it and leaning it out. The backfiring sounds like your not getting enough gas, if you took any jets out did you count the turns to make shure you have the same settings. If the carb was dirty a jet might have been clogged and they may have messed with it to run the way it was, now that it is clean you might have to adjust it to its factory settings to start over. on my 660 Rhino there is a brass cap on the jets so you cant get to them, was there on yours?

 

The jets looked clean when I had it apart I sprayed them with cleaner and blew them out with the air gun just to be sure. The Pilot mixture screw was out 2 1/2 turns so I put it back that way. That is right according to the book. I know it is lean but wondered if the diaphragm could cause this. I guess it could but dont want to spend more money chasing the problem. So I ordered the Carb today and will keep this one for a paper weight.

 

Wondering if you found out the running problem.I am having the exact same problem have been thru all the same components you have with no luck,did the new carb. work?

 

i have the same problem with my 05 660 let me know what the problem was please good luck if i find out il let you know

 

Yes the new carb. fixed the problem. It starts right up and runs great.