2000 ultra 150 #1 piston failure

[mitymouse63]

need some ideas on what to look at on this unit i just replaced the piston and cyl on this unit also went thru carbs replaced all oil oil injection lines cleaned and flushed cooling system put unit back together ran on hose did great put in the water ran great ran unit for about an hour ran great unit was run for several hours and ran out of fuel was refueled with plus unleaded gas ran for about twenty minutes and the #1 cyl burnt up it is actually burning a hole down the exhaust side of the piston the other side is showing scoring also but has oil all over the piston skirt does anyone have any ideas of something i could be overlooking please help

[Technical Support]

Re: 2000 ultra 150 #1 piston failure

If you ran it out of fuel while running wide open you can cause damage to the engine, the engine will run lean as the gas runs dry and cause scoring.

[mitymouse63]

Re: 2000 ultra 150 #1 piston failure

i have attached a pic of the first piston this is what is puzzling me and yes my first thought was its happening after being ran out of fuel the piston looks like a detonation issue but confined to the one cylinder is there something that i need to look at on this unit i don't want to put another piston and cylinder on unit and return it to the customer and it fail again is there a throttle position sensor on this unit