my nephew bought one for 1900 ran great brought it out to my house we were riding in a field (about 15 min doing donuts opening it up some being a 2 cycle wanted to clean it out and get it reved up a little) it started sputtering and stopped when I hold my hand over the exhaust there is no compression when I turn it over so thinking need to pull the motor and rebuild it if OPT has some schematics and parts lists I would appreciate it its just a project at this point no real rush on it

 

Her's a service manual that includes the 400 engine as the 400 engines were the same over the years.Be sure to check out the bottom end,rod play,bearing noise,ect. Just my two cents,I've seen too many that didn't last with just a top end rebuild. Look over the manual as to what's all involved. Index of /ORV Manuals/Polaris/1985-1995 - All Models

 

thank you opt that will help a lot