Question

[450R-156]

Had my top end re done this fall on my 450R and i finally had a chance to start it up the other weekend and it was running good for a litle bit then, it started dying on me had to give it a litlle bit of gas every few seconds to keep it running, then I adjusted the idle and it was running fine till it started back firing pretty bad. So I shut it down and this all happend with a period of five minutes. It was late so the next day i tried starting it again and one some kicks it felt like there was no compression. Does any one have any ideas on what this would be, i thought it might be the valves but i am not very good when it comes to engines

Plug?

[pro-rider46]

hey. check to see if your decompression is set correctly. the 450rs have a auto decomp. and need to be set to the correct spec. i dont know it of the top of my head, but i know that it is important to get it set right.

[450R-156]

I started it up again and it does have compression, it starts and runs fine for a minute or so and once it gets warm then it starts to backfire and then die