Hi this is my first post so please let me know if anything needs to be changed or clarified.
I just bought a big bear 350 yesterday, the previous owner said he had problems getting it started and running after about three years of him owning it. So far I have clean the carburetor replace the spark plug and have had no luck. I have also tried spraying starting fluid into the intake and pull starting it and it doesn't even pop. Thinking it was the timing I checked that and it seems to be very close. I have not checked the valves yet because I'm not too sure how to. Please let me know if you need pictures or anything else explained or have any ideas what to check next thank you.

 

sounds like could be fire or compression[value could be tight on intake] may have to get an repair on atv guess before do value adjustment if never done one before

 

Check for a spark first by laying the plug on the head.

 

thanks for the suggestions, i actually took the cam out and the lobes on it were very worn down so i think thats my problem.

 

Check the compression To! Put your finger over the spark plug hole and have a freind pull the pull start. If the cylinder cant at least blow your finger off the spark plug hole (while your pressing hard on it) the compression is SHOT