Alright, shun me if you want for asking about a 4 wheeler on here but it's kind of urgent that I find out the problem. I have a 2003 Yamaha Kodiak 400 4X4 and I went to take it for a ride tonight and it seemed like it had no guts at all and two days ago it ran like a champ. So after it got warmed up I decided to see what it acted like at full throttle and it spit and spuddered like it wasn't getting fuel but would keep the speed that I was at (which wasn't very fast). So I switched to reserve thinking that it was at that point and it still does it. After I got back to my house I kept running it hard for a little bit thinking that possibly the plug was damp from washing it. Well I gave it one last run and when I let off the gas it wanted to keep going!!! Finally it settled down and when I turned around, what do I see? I huge cloud of blue smoke! And it didn't smell like oil. I dont know what it smelt like... Anyways it idles great but when you take off and give it about 1/4 throttle you can already tell that it is guttless. And at half to full throttle it is just horrible. Anyway, I checked the gas just for ****s and giggles and the last time I checked, REGULAR GAS ISN'T BLUE!!! Now, my dad swears that he didn't put 2 cycle in it the other day when he filled it up for my sister and he knows about that stuff too so he wouldn't do that anyways. I asked my sister if she added any extra fuel when she got to the trails and she said no. So, I have no clue how this possible 2 cycle gas got in it. And yes it is carbeurated.

 

when I had a yahaha blaster and it did the same stuff you describe it was a bad carb. as for the gas, someone had to mess up

 

Alright I will have to check that out. And I have literally no idea who could have done it. It may be regular gas but from what I can tell, it looks like two cycle.

 

even if its 2 cycle you can still run it, and it it shouldnt be too bad. Id check the carb

 

Okay. The only problem that it would cause is it would foul the crap out of the plug. And I will check it.