what causes engine failures

[bustamove]

so im sure you guys have seen my numerous posts... im just trying to cover my.. BUTT, this time. so i completely rebuilt my engine.. new everything...

went riding for about 20km then bam blew apart mag side cylinder.. skirt broke off as well not sure if that was the cause or happen cuz of something eles
i premixed yes.

i did use spi pistons is that the cause?
i also dinged that injector a bit... took the chance of running it... im getting them tested to see if it was running lean
checked carb boots- OK.
heard something about throttle bodies?

anything you guys got throw it at me... i want this to be the last time i put money into this motor... also i have having bad running problems after i went into reverse off the truck.

also can you get just the rod bearing for the big end?

 

[Danbot]

so im sure you guys have seen my numerous posts... im just trying to cover my.. BUTT, this time. so i completely rebuilt my engine.. new everything...

went riding for about 20km then bam blew apart mag side cylinder.. skirt broke off as well not sure if that was the cause or happen cuz of something eles
i premixed yes.

i did use spi pistons is that the cause?
i also dinged that injector a bit... took the chance of running it... im getting them tested to see if it was running lean
checked carb boots- OK.
heard something about throttle bodies?

anything you guys got throw it at me... i want this to be the last time i put money into this motor... also i have having bad running problems after i went into reverse off the truck.

Use only 2006 Polaris pistons, all others including SPI are known to be less reliable.

Yup, probably shouldn't have risked that "dinged" injector, have it bench tested or replace it

Air leaks will kill an engine quickly, intake boots, crank seals etc

Proper warm-up is a huge thing for me, you just can't be too cautious warming up your engine evenly, and heat soaking before you ride.

With the way our oil injection works on specific point lubrication, its a good idea to add some pre-mix to EVERY tank, not just the break-in tank. This will ensure your pistons and rings are getting proper lube.

 

[94fordguy]

Agreed with Dan

Check throttle body boots, seals, tps for proper setting, and a THOROUGH warm up. Check oil lines to make sure you dont have any bubbles and have no lubrication problems. When warming up, you can place your finger on the head next to each spark plug to feel that each side is warming up evenly... that can discount a possible cooling blockage or other issue. Also agreed with the pistons, I would not put ANYTHING except 2006 Polaris pistons in a 900, they have been proven to be the absolute best out there for these sleds.

How much oil did you use to premix? You dont want to clog the injectors with too much oil.

 

[danduvall]

What would you say is a good amount of oil to run in each tank of gas? Id like to keep some sort of little jar or cup on my sled so I can add oil to my tank when I fuel up on the trail!

 

[Z-Man]

IndyDan said he adds 1 pint of oil per tank or 100:1 premix, so that is what I plan on doing.