Alright so im not so sure about these new 450 motors, I have an 05 450 with about 100 hrs on it, so anyways i started it up today and it kept killing every minute or so which i blamed on the cold weather (32 deg) after i let it warm up for 4 minutes i took it out and everything and as i was going it just killed acted like it was locked up. SO i pushed it back home and had to put it on the battery charger to start it battery was getting weak due to cold temp, and it cranked over a few times but nothing so I pulled the spark plug and it cranked just fine even gave me a mist cloud of fuel shot out it was prob flooded from the previous cranking. I reinstalled a new spark plug, and tryed it again this time it would crank very slowly once or twice and even pop like it was going to start, but nothing. So i pulled the plug again and tryed cranking some more but this time it won't even make a full turn it maybe makes an eighth turn every time i hit the start button. The cylinder is dry, and was thinking maybe a broken ring or something else bad, but i don't see any metal flecks. The piston is also still moving but is acting like it is binding. It has plenty of oil, any ideas?

 

It still has the trade mark thunking noise from the higher compression piston, do you guys suppose it may have become hydro locked in the head or maybe even iced up?

 

What did you do to your quad in the way of mods? What did you mess with just prior to this happening? If you havnt already, go over to yfz tech, or yfz cntrl (misspelled I know, but it wont let me write it correctly) I am sure you know the site I am talking about. There are some good guys over there that will beable to help you out!

 

No engine mods, except the spark arrestor being pulled, but thanks for the advice i'll go check those guys out.

 

Do not pull spark arrestor unles u jet ur carb thats houw i blew my engine in my old 250ex