odd engine failure

[tnt-salvage]

today we went to go for a ride and it went down on mag side. water temp was 122 before we left the trucks, it made it 10k down the trail. egts were in high 12's-low 13's highest i seen was 1325. they dropped to 11xx then one quick short pull of throttle and it shut off.. tried to pull it over and was hard to pull over. pulled plugs and mag side had a few silver speckles on it. seems to roll over fine now but will pull it apart today and see how it looks. any idea what would have caused this? sled has just under 1400 miles. running straight av gas and opti-2 oil

 

[slededjr]

Possible leaned out? Why so high on egt's if not wot? I try not to go above 1260 at wot on long pulls. Like to run high 10 ' s at low end and mid range. Does this sled usually run at those temps? Post a pic of what you find.

 

[tnt-salvage]

yes sled has been running great as it was set up. looks like lack of oil to me though? once on top the egts dont seem to go above 1280 its just a certain spot in the throttle it will climb high. my grampa's 13 is the same way. i will take photo's soon i just got the top end off and it looks like i need to have the cyl plated and replace the pistons.. i was told to get a lower comp head for it. also mainjet is using m8 pistons in there pro's but the guy could not tell me what year they were for. what is the best piston choice for me? i would like to go ridding next weekend if possible

 

[tnt-salvage]

Well it was not an oil issue. It just got hot and started to seize. Ill post picture tomorrow but the cyl has to be replated. I can only think it ran lean for some reason? Crank seal or fuel injector failing or plugged maybe ?

I have been told by mainjet there using m8 pistons in there pros and I have read about all these fix kit's and I would like to ask you all what is the best piston I should be using ? will the standard wiseco pistons work? Or will these have the same issue the stock ones have ? Was also told I should drop my compression a bit with a turbo head. I was running 7.8 pounds prior to today and today after resealing the exhaust I was making 8.9 pounds of boost. Once I rebuild the top end I will be 9-10 pounds and straight av gas. Riding from 6000 feet or higher. Please any advice is helpfull as I am hearing so many different things to do or use