I have a 2004 Grizzly 125 and since it was new it has had a hesitation from a dead stop. If you try to take off fast by giving it half to three quarters throttle it will hesitate (the engine will stumble a little) and then it goes. If I try and do a full throttle start it will fall flat on it's face. By flat on it's face I mean sometimes the engine will actually kill and others it will stop just short of killing , It will sputter and then take off. Off idle it runs great. I have tried richening the fuel mixture, I have tried leaning it out and I have played with the idle and nothing helped. It is back at the dealer for the third time for this problem and the service adviser doesn't think it should do it, But the mechanic says it is normal. I also noticed sometimes I have to blip the throttle to get it to idle down all the way. I pulled the spark plug out and it was black and sooty, But the dealer says it is still to lean. It may be lean at idle, But not off idle or the plug wouldn't be black would it ??? I call B.S on the part that it is normal and I told them I don't want it back until it is fixed because the warranty is up in a week. Anyone else have any input?? This is the only complaint I have with the machine other than squeaky front brakes, But it sure is annoying. What recorse do I have it doesn't get fixed this time as it is the third time in for the hesitation ?? Thanks in advance for any help.

 

If you think it's running rich, take the airbox lid off and see if it clears up. Or turn the gas off and gun it and see if the engine runs better as it runs out of fuel.

If you think it's lean, try partially blocking the snorkle tube (assuming it has one). See if it runs better.


1/2 throttle would be the needle jet and it WILL affect full throttle too. Always go pilot to needle to main. In that order.

Are you at an extreme elevation?

 

No I am not at any extreme elevation and I have tried actually adjusting the mixture richer and leaner and it didn't seem to make a difference. Once it is off of idle it runs great.

 

Once off idle or once you get moving? You should not have to mess with your mixtue. That only affects the idle and not so much how the quad runs.

Wondering if it's a carb problem or a clutching problem?

 

It is definately carb because from a dead stop if I try to do a 1/2 to 3/4 throttle start the engine will either sputter a little and then go or it will simply hesitate and then go. If I try and do a full throttle start most of the time it will just sputter and kill. If I feather the throttle to get the bike moving then it is fine, But it will not take off fast. If I go up a small hill and stop in the middle, When I go to start out again and give it enough throttle to keep from rolling back the engine will hesitate.

 

Well, I guess what I'm thinking is if you can pin it while rolling and there is no hesitation and it runs great, then that sounds like it could be a clutching issue. If you do think it's jetting try the tests and see if you get results.

Don't know if the Breeze has the same cvt set up as the mini's? Anybody know?

 

Thunderbolt, to me that sounds real lean. It's hard for me to say though without being there. Sounds like the fuel curve is all screwed up. Maybe a rich idle and a lean main? Who knows?
I would find a new dealer if they told me it's "normal" for a motor to stumble!!!!
Raptorlegs has some very good advice. Let us know how this turns out.

 

I will let you know. The dealer has it right now so we'll see what they say. After thinking about it, The other reason I know it is fuel and not clutch is because if I put it in neutral and snap the throttle it stumbles and sometimes kills. I thought lean to, But the plug is black and sooty. I wish they would just put a new carb on instead of taking it apart 50 times. If they don't get it fixed this time what is my recourse ?? The warranty is up Nov. 10th and this is the third time they have had it for this problem. Maybe call Yamaha ?? I like the dealer itself as they have been good about it, But I am wondering about the skill level of the Yamaha tech. they have.

 

Sorry to hear about the problems, but I think youll be covered. Seeing how it was brought in under warentee, and still hasnt been fixed, its still their problem, even though the warentee is up. Just like car and truck warentees.
Has it always done this? Or did it just start acting up?
Could the gas be old, or water in the float bowl? Try draining the gas, and put new stuff in there,(try to find pure gas and not the ethenol crap, the Spur in Forest Lake sells pure gas, at one of the pumps). Could there be an air leak in the intake ? Or loose bolts on the tube?
I like the suggestion of trying it with the air box lid off, and then trying it with the snorkle partially covered. The air lid removal, will really lean it out, and the covered snorkle will richen it up. One will make it much better, and the other will make it worse.
My guess would be, lean. And this could come from old or enthenal blended gas.
Heres an article on jetting and on symptoms of lean and rich. http://www.motorcyclecruiser.com/tech/jetkit/
This model has a non CV type carb. Its just a slide type, and the slide can be opened fast enough to produce a bog..in fact this is why most atvs have CV type carbs, to prevent that bog. If you open the throttle slowly..is there any drivablity problems? Is the large nut at the top of the slide tight? Is there a gasket, under it?
Let us know how it goes.

 

Drew, It has done it from day one. The carb has been cleaned, the tank has been drained it has had unleaded, premium unleaded and premium unleaded without ethanol and it still does it. If I slowly give it throttle it is fine and after the rpms are up a little it is fine. So this actually could be normal ??