I was going to install a 440 kit in my 400EX, but I have heard that 440 kits are not durable and thay blow. Than you have to keep buying
440 kits. Like I said this is what a couple of people who have them told me. I now am thinking of getting a smaller bore kit.Anyone who has the kit please let me know.

 

I have had my 440 kit for over a year now. No problems except a blown head gasket, which was my fault(didn't properly torque). One thing that will prolong the life of your 440 would be to go with a mild cam instead of a race cam. I also use 93 octane gasoline, which is much more gentle on your engine than racing fuel. Mine runs just fine with 93 octane.

 

i have the 440kit w/mid cam and have been riding hard for 8months on it. i havent had 1 problem. I called the cyclesports here and they told me i could bore it to a 453cc and it would still be more reliable than a stock banshee. The only rumor ive heard is that they cause the rear end to blow but i havent experienced that either. I have experienced my clutch going out faster than normal but i got heavier springs w/ the stock oem plates and it does fine. Do not buy a barnett, they only hook up good for 2 days until they are toast. want pics, email me

 

Mr Demon,
Are you using synthetic oil? If you are, stop. It puts a glaze on your plates/fibers. In all actuality it's too slick. I went thru 3 cluthes before I started using Honda GN-4, no problems now. I get it for free, that's why I use it. I am still running the stock basket with a Dirt Digger clutch. The only reason I got the Barnett is it was in stock and the OEM was not. I haven't had any problems so far. I've got a Hinson clutch basket with the 250r OEM clutch [1 extra plate and fiber] waiting to go in it when needed. Also, get the TCS shocks. You will be more than happy plus you will get the best service available. Send me some pix of your bike. -RT