Hi I have a 2000 scrambler 400 that stopped running today. I went to pull it over (starter is crap) and it started up, ran for about 10 seconds, then died. Now it is impossible to pull the rope. Idk if it makes a difference but I was ridin it out in the snow all day and it was only about 2 degrees above out. I recently had the head off to clean it and the piston off and also had the carb apart. I have overheated it a few times in the past and I think my radiator might be partly plugged. Each time I have overheated it the overheat light came on but it did not come on when it died this time. I am wondering if it is seized and I need to bore it out or if it is some other less expensive fix. Let me know what you think.

 

Try taking out the plug and putting in WD-40 to see if it can be pull started after sitting for awhile. If not it could be seized.

 

check the clutches first. a belt could have broke a belt and jammed

 

maybe u could go up a main jet size for cold weather like 2 degrees??