somebody help me please.... Our local shop has my quad and can't figure it out. We have swapped the stator, voltage regulator, battery, coil and plug. We have checked the timing and its 45 degrees or so off center and can't figure out how it got there. I was puling fence posts in Reverse and she died. Now she won't start. Any ideas are good ones at this point. She's been down for two months now and YES it has gas in it.

 

I'm assuming that it fires? But won't run? If it's 45° off from TDC.......I'd hazzard a guess that you've stretched the timing chain or spun the bearing on the camshaft gear. Yo may have even jumped/broke a couple of teeth off. It's no wonder it won't run being THAT far out of time.

At worst you've bent valves/damaged the piston...basically buggered the head, and hopefully it doesn't extend lower. (does it hammer/clunk/grind when turning over?)

I'd drain your oil and check for metal.

Sorry to be the bear'r of bad news.........

 

Or the bevel gear broke and the pieces flying around in the case did the rest.

 

X2!!

 

I bought an 07 400 not running (very well, anyway), found out the cam chain was stretched. It would idle okay, but rev it up it lost power.

Simple way to check that - pop the cam cover off - is the chain at all loose? Check it on the back side, see if you can move it around. Then, check the tensioner, right side of the cylinder on the back, about halfway down the jug. Take the spring out first (center bolt), take the tensioner out (top and bottom bolts), is it ratcheted all the way out? If the tensioner is all the way out and the chain still has some play in it, you have a stretched cam chain.

Not real hard to replace. Take off the belt drive on the right side, drop the chain out the bottom, feed the new one in. I'd suggest you replace the chain guides while you're in there, they don't cost much. Sure runs good once you get a tight chain on and time it properly.

 

Just a heads up - I learned this the hard way some years ago. Reverse gears are weak on just about any transmission, because they reverse the direction of the power. Weren't designed for heavy loads like towing or pulling. You can break them if you pull or tow.