hi guys I posted a couple weeks ago about blown powerhead. I have pulled apart #6 piston broken bent rod block vented.wil be replacing assy with reman. trying to find cause have questions and hope you u can help. I am mater Toyota tech 25 years. still learning my boat motors I have 2 others 50hp merc 85hp force boats for years run great. just purchased 4 mos. ago 1996 nitro 884 savage 150xri efi nice boat. only got approx. 4hr use before this happened.now apart I see very worn cylinder walls a lot of unmaintained use my fault but I own it so want to do this right. I thought it would be caused by fuel issues. installed fuel inj pres cleaning system to fuel rail 36psi injectors fire in pairs test show flow rate and pattern on all 3 set the same. res test injectors ok. since only #6 failure #5 fine same ecm output can I assume emc ok ? was running at 60+ mph just before this happened. was told was pro tuned just before purchased. my fault for trusting seller. icleaned fuel sys fresh no eth fuel before I started first time. what else should I check any advice would help did not check link and sync or timing, sensors, oil sys. not sure why only 1 cly failed has 3 different piston in eng so has been apart before. I only want to do this once. sorry does seem detonation prob and cause
