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Hi Guys!

I take, I give. Loved to read through forums to orient my assesment on my Sportsman 400 HO 2011. I did not find the exact problem I encountered on the forums, but forums helped me to find it quicker, so I'll explain what happened: Rode my bike wintertime as usual on packed snow, nothing special, but in a matter of about 20 minutes, I've experienced a progessive power degradation. No weird noise, no leaks, just the fact that the bike could'nt go any quicker than 25-30 mph, and hardly get there to say. Idles fine, starts perfect. Removed the big bulky black cover to look at my clutches, all looked perfect and seemed to cycle normally on throttle response. Then I started reading. Checked compression: OOPS! merely 60 lbs = problem. Before to start crying, I've started to read forums. First thing, you can't read this engine's compression the conventional way since it has a functional startup decompressor. Did'nt go too deep in that, so I kept reading. Some guys had a worn-out exhaust lobe on their camshaft and they seemed to have experienced the same power degradation as I had. Although I was a bit skeptical about camshaft issue since my bike has less than 4000 miles on it and been maintained meticulously. Plus the degradation happened a bit quick to make me believe it wore in 20 minutes or so. Another guy told he had an issue with his carb. His needle locking ring snapped off and the needle fell into the jet. That sounded a ring, and other guys told that the newer HO's like mine have a camshaft that will last. So I pulled the airbox flange out of the card and ran the engine a bit. I noticed that the flatside would NOT go up. I looked to me like a vacuum problem. I then removed the cap on top of the carb to see who's responsible : the flatside diaphragm. I fixed it temporarily with super glue and windshield urethane for a testing purpose. I noticed that the flatside guide Inside the carb body is plastic made and has (2) sharp edges that obviously cut my diapragm over time. Needless to say that I filed them round just a bit. Once there, I remove the valve cover and checked the valve/rocker GAP: Under 6 mil=brand new no need to adjust. That made my day. Put everything back together, ripped the trail for a minute, all is fine. RESULTS: I ordered a new diaphragm at my local dealer:133.00 $ CAD. in Victoriaville, QC. Fair. Will ride my thing like a boss this weekend, :cowboy: thanks for your attention. Nic.
 
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