[hawkins109]

So I'm looking at a couple different bikes and don't really have a huge budget so I'm looking at some 400ex's that need some work. One I came across is a 2007 that has apparently jumped time and also needs valves, but appears like mostly everything has been left stock. A friend of mine said it may possibly need a rebuild as well. Overall it doesn't look like it's in the best shape, but it's for sale for $500 and I'm wondering how much it would be to fix it and have something to ride around on? Another one I've found is also one that looks to be in much better shape for $500 as well but its a 2003, which also has a 440 kit but needs rings and a starter button. Would the one with a 440 kit be the better option and cheaper to fix, or what would be the best option?

 

[SlammedRanger]

I would go for the 07. They added reverse to the 400ex in 05 so as long as the motor on it is original it will have reverse. They also added some other updates that make it more trail oriented. Also the 440 big bore kit is a ticking time bomb. If not done properly they will blow head gaskets weekly. I personally turn and run from any 440. Way to many hacks out there building quads that havent a clue as to what they are doing. My.02 Welcome to the forums!

 

[hawkins109]

So let's say the 07 does need a top end rebuild, how much would I be looking to spend to get it up and running? Or does jumping time and needing valves fall under a completely different category? I'm fairly new to the atv scene, but I know some people who would be more than willing to help me get one running. Haven't rode in a while, last thing I rode being a dirt bike, so any and all help is much appreciated. Thanks for the welcome note as well!

 

[dr. feelgood]

If it jumped time, worst case your looking at is 2 or 4 bent valves. You could replace all of them for around $60 (Shindy). Since motors don’t normally jump time it would be wise to replace the timing chain for around $40 (OEM). Figure another $20 for a top end gasket kit with valve seals.

If it were me and I had a bit more cash to spend, I would consider putting the next size piston in it while it was torn down. That would be around $100 for the piston kit (Wiseco) and around $50 for matching bore at your local (trusted) machine shop.

Rob