Well, since I bought the 07 Wolverine 450 Special Edition my carb kept sputtering everytime I would go threw mud and would get stuck because of it. Well, I now have 250 miles on the bike and went out last weekend. It has been raining fri and sat and went muddin Sunday hoping to play in the mud. Well, I took my bike out in the myd trails and it did better then ever...So I kept getting deeper and deeper in the mud to play...I wanted to push it....It was doing amazing and it did not sputter...Well, I decided to take it threw a huge mud lake....I was up to my handle bars and my legs were also on the handle bars because of how deep I was..This lake was about 100-200 feet long...The bike went through the WHOLE lake...Floated, wheelied, and just went AWESOME. The Carb did amazing the whole time I was out there..I had a crowd watching me go through the lake and were amazed I made it....I almost sold my wolverine because of the carb but since this, I decided to keep it...It did an AWESOME JOB!!! The ONLY problem I have is my belt gets flooded quick...I might have a crack in my seal...Other then that the Wolverine proved me wrong after 250 miles later...I guess the bike needed broken in...

So here is some info for people with the sputtering problem...Give it time, and push it to its limit and just wait it out....The bike is badass!

 

Yhea I would definetly take the cover off of the clutch housing because I take a creek bed(over handlebars several times) about 2 miles long, atleast 2 times a week and have not gotten any water in my housing. I have to agree though It does seem to get better.

 

maybe its cuz you broke it in with synthetic oil? my ds250 keeps getting better (well it might have stopped now, but it takes a LONG time to truly break it in completely, but after 50 hours of riding you will notice that it is much faster than a brand new one, feels many times faster