I need some help here boys. Here is my problem. Put D&D trail pipes into stock can on my 1000 t-cat today. Machine has 4400 miles on it. Before the pipes were added I drove it and my engine reved at about 84-8500 rpm. After the pipes were added, took it for a ride and the engine reved about 8500 rpm. No clutching changes. Shouldn't this thing rev out more if it was making more power? I know I have to clutch it for about 87-8800 rpm, but I thought it should have reved out higher if it was maker more hp. But than again that is the least of my problems. I come back from a test drive. Adjust my secondary, and go for another test drive. Engine is warmed up 126 deg water temp.I drive 200 feet slowly and than nailed it about 3/4 throttle, the skis lifted and I let off and the engine dies. Ripe the engine apart and the center piston is exploded. Pieces of it everywhere. Cylinder is good and so is the head. But there is a hole in the bottom case, that is not supposed to be there. Upper and lower cases have holes in. What happened and why. Engine was warm and I just rode it for 2-3 miles. Hottest the egt's showed all day were 1200 at wot. Highest it reved was 8500. What causes a piston to explode? Is it the 4400 miles that are on the piston? Should one have put new pistons in with that many miles on, when you add pipes? It was definitly making more power just not reving out yet. Any suggestions?

Now part 2, Who has a crankcase for sale or perhaps a complete egine, 1000 or bigger. Trail only. Thanks guys puss.

hey whipped (sorry about the sled and the name )
Sounds to me like you probably had a tired piston when you switched pipes and maybe the added stress of a different pipe resonance caused it to come apart... As piston wear thin on there side walls from usage they become more and more vulnerable to skirt breakage. I have found this to be especially true with big bore engines!! I have to watch my KX500 (dirt bike) very closely cause it will show NO sign of getting ready to do what you are describing and BOOM - it can happen!! THe best way that I knw of to protect yourself/machine is took take a peak thru the exaust port occasinally and see how each piston is doing!! IMHO the more cylinders you have the less heat wear you get (cause you can run a smaller bore to accomplish the amount of displacement you want) so the more miles you should get from your pistons BUT they still will wear!! Depending on where/when/jetting/seal conditions ect... you needed to check your piston for scuffing sooner!! Also, when those pistons let go they have NO WHERE to go but thru the case! THere is VERY little room between the crank and the case wall and it is VERY common to lose the case halves too!! Try E-Bay (seen a 1000 motor on there last week) and the sled yards for your parts needs!!
Bummer about your sled man!
Woodsy

Thanks Woody :div20: That is what more people think. Piston fatique. The other pistons do look good, nice and smooth. A guess I should have changed them, when the pipes were added. Thanks puss