I've got a 08 800 and the other night it started running terrible. I ran the codes and its flashing a code 21. I've been told it has something to do with LOSS OF SYNCHRONAZATION but nobody seems to know what that means and I'm at a loss. The things backfiring, want idle most times and as soon as you touch the gas it bogs and dies. Any help would be great.

matt

 

hey matt, a loss of synchronzation mean the crankshaft position sensor it sensing a uneven rotation you need to take your machine in and have them put it on the digital wernch software. This software will check/test your machines sensor and find which one is acting up and causing you problems. 07 500 and 700 and 800 had a couple of issues with the tps and maf sensors

 

I've heard of a few bad crank sensers. Might be time to take it in, otherwise you could spend a lot of time and money guessing at parts.

 

Thanks for all the help guys but I ended up tracing it down. Theres a little o-ring around the base of the Mass Air Flow sensor. The sensor on top right behind the trottle body. Anyway I pulled the sensor off and there was a drop or two of muddy water right on the tip were the sensor is. Sprayed it with WD and blew it off with air and it was good to go. Looks like a little sillicon around the top will stop the problem.