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Offroad => MXU => Topic started by: mdllucas on December 24, 2014, 05:54:00 PM

Title: need help
Post by: mdllucas on December 24, 2014, 05:54:00 PM
While warming up my MXU 500 with the choke on it stopped (after about 10 min run time). It would not restart. This happened before and had to take it to the dealer for repairs.The dealer said they had to rebuild the carb.It has only ran about 2 hrs. since rebuild and is doing the same as before. Is there anything I am doing wrong and can i fix it myself? The dealer is two hrs away.
Title: Re: need help
Post by: BettinANDlosing on December 24, 2014, 07:22:28 PM
While warming up my MXU 500 with the choke on it stopped (after about 10 min run time). It would not restart. This happened before and had to take it to the dealer for repairs.The dealer said they had to rebuild the carb.It has only ran about 2 hrs. since rebuild and is doing the same as before. Is there anything I am doing wrong and can i fix it myself? The dealer is two hrs away.

How long ago was the carb "rebuilt"? If it was months ago, and youve only used it for two hours since then your carb is dirty again. You HAVE to drain the fuel out of the carb if the bike sits.
Title: Re: need help
Post by: souzamoto on December 24, 2014, 10:03:47 PM
I think 10 minutes on choke is way to long. I would check the plug as it it likely fouled. You may want to bump up the pilot jet a size or two so warm up time and idle is improved. Fresh fuel is recommended also.
Good Luck
Title: Re: need help
Post by: zombie on December 24, 2014, 10:58:26 PM
I am thinking something similar... Have you adjusted the Idle Mix screw?
Not to the "factory preset" of 2.5 turns but actually adjusted it for the best idle?
Title: Re: need help
Post by: mdllucas on December 27, 2014, 05:14:25 PM
The rebuild was about two weeks before deer season(gun) it ran fine for 4 to 5 days at camp then it turned cold and i was letting it warm up and got side tracked,that is why it ran for about ten min.I will check the plug and drain the gas for winter.I hope this will fix the problem.  Thanks for all the help.
Title: Re: need help
Post by: mdllucas on December 27, 2014, 05:41:52 PM
Just wanted to add that this is my first ATV, I am 65 years old and use the atv to get to my tree stand now that my legs don't work like they use to. I know a little about motors but these new ones,(2008) do i have to say more? I do appreciate all the help i can get.
Title: Re: need help
Post by: zombie on December 27, 2014, 06:02:22 PM
The engine is the same as any old lawn mower you have had.
The CVT is what throws folks off.

Maybe this will help some... There is a large spring that holds the rear pulleys closed. That makes the belt ride high on the pulleys, and holds a low gear.
The front pulley has "rollers" inside. They are basically weights. As the rpm goes up those weights force the rear spring/pulley to open, and that raises the gear ratio.

Lighter rollers take more rpm to open the pulleys, and heavier rollers open it w/ less rpm.

https://www.youtube.com/watch?v=5a70U5-n984 (https://www.youtube.com/watch?v=5a70U5-n984)

https://www.youtube.com/watch?v=iPA6VK9cP20 (https://www.youtube.com/watch?v=iPA6VK9cP20)

https://www.youtube.com/watch?v=iPA6VK9cP20 (https://www.youtube.com/watch?v=iPA6VK9cP20)
Title: Re: need help
Post by: BettinANDlosing on December 29, 2014, 07:29:25 PM
If it ran with the choke on for 10 minutes maybe the plug is just fouled.
Title: Re: need help
Post by: mdllucas on May 21, 2015, 08:24:27 PM
Thanks for the help everybody and BettinANDlosing was right it was just a fouled plug.Replaced it and it fired right up.Again thanks