Here is my question to hopefully someone that can help me. My 04 Rhino 660 runs great when its cold. Once it warms up it seems to have a spark issues. If i make a complete stop and then floor it, it just sputters till about 4mph and then takes off!!! Once its up and going it runs good but still has a small misfire. If i try going up a hill from a dead stop it sputters so bad that i cant even go up the hill there is just no power. It is the same exact thing that it does in reverse when it hits the reverse limiter. Any ideas?

 

Yes, ... pull the engine cowling off and check the green wire with white strip that you will find near the oil filter. That is the wire for the reverse rev limiter, and it may not be connected securely enough. Good luck.

DV

 

Why would that cause it to run that way in the forward gears also? And only once the engine has been warmed up?

 

First thing to do is to clean your air filter and put in a new spark plug, Second thing is to make sure your choke is operating properly closing and also releasing. It may be sticking a tad and causing a rich condition. Lastly clean your carb with carb/injector spray and also put some in your gas. You may eventually have to take the carb off and thoroughly clean it.

It sounds like your pilot jetting system if off a tad. Your pilot system is most dominant at idle to 1/8 throttle. This is why you can't run good until about 4-5 mph..., when the main jet then becomes most dominant but it takes a few seconds for your engine to adjust to your rich pilot settings, that probably is also why it sputters. Same effect as if your choke was still on.

If you have EFI, take it to the dealer and have them adjust it.
If you have a carb, than you can adjust it yourself.

On a carb the pilot air/gas mixture screw is generally located on the bottom of your carb. (Not the idle adjustment screw)
Turning it in will generally lean the mixture, turning it out will make it more rich.
In your case it sounds like it is too rich and needs to be turned in.

To set it, you turn it all the way in and then out 2 turns, this is your reference point and your machine should idle fine.
While the engine is running turn it in until it stops to idle smoothly - make a note.
Then turn it out past the initial 2 turns and keep turning it out until it stops to idle smoothly - make a second note.
Split the difference between your two noted points and you should be dead on, I generally will tweak mine 1/16 turn out to be a tad on the rich side.

While turning it in or out allow about 10 seconds for your engine to catch-up with the adjustments. So turn them in and out slowly.

Another less effective way to set the pilot, is to run wide open and then completely get off the gas if it doesn't pop or backfire then lean it out a little and do it again - keep leaning the pilot screw until it pops or backfires, then richen it up until it doesn't pop or backfire.

 

Ive cleaned the filter and changed the plug. I can change all the jets and change the air fuel mixture screw and still it does the problem im having. It seems like the reverse limiter is doing it in forward gears too.

 

Mine recently started popping when I let off the gas and then started to stumble. I replaced the fuel filter (behind pass seat) and it solved my problem.

Rude Dog