i think i seized the crank bearings.

[shad0]

today i got the new reeds/reedcage, intake, carb and air filter for my sons quad... 90cc polaris scrambler X

i spent the entire afternoon installing the new equipment and disabling the oil injection.

after a bit of fiddling, i finally got it to run. once i got the idle screw set, it seemed to run great. i had already mixed 32:1 and drained the tank before adding the premix.

i had it up on the stand running, and it seemed to run great, until you would open it to WOT. then it would start to sputter and cough. up to 2/3 throttle it ran great and had great response.. after trying to run it at WOT for a few seconds and it sputtering and coughing, it started to smoke pretty bad out the exhaust.. when it became appearent the smoke wasn't a momentary thing, i let off the throttle to prepare to shut it down. as it was winding down, the motor seized and the motor won't crank even applying full pressure to the kick starter. i have to work in the morning and i was disgusted so i shut down for the night. tomorrow i'm going to tear into it and see wth happened, but i'm thinking the crank bearing seized or a ring gave out.. what do you guys think.

 

[dharbeck]

yes it sounds like the pilot and needle settings were right but that the main jest was off.

 

[Hairyblackdude]

It sounds like you melted the piston...

 

[89custom]

its cuz its a polaris.

 

[wrench man]

Yep, lean top end and seized the piston.

 

[blasterboy91]

bummer =/

 

[blasterman312]

I bet your boy is pissed!

"daddy, your a poopyhead!"

 

[shad0]

It sounds like you melted the piston...

we have a winner!

i pulled the head and cylinder off. luckily, no damage to either of them at all. the rod feels sloppy as hell on the crank. alot of side-to-side wobble. but the piston shed 25% of it's mass. going to split the case either tonight or tomorrow and see where i'm at. i was talking to the guy i get my parts from, he doesn't think the crank or rod will need replaced, but he wasn't surprised to hear about the piston. if i get lucky and i only need crank bearings, seals and a piston, i'm looking at a relatively cheap fix ($60'ish). if i need a crank, add $100 for a race crank. but being that he races and sells mini atv's, he thinks he'll be able to come up with somebody who has a used 90cc crank lying around if it comes to that.