Predator 212 backfiring out carb and wont start

[Karttekk]

I have heard this as well but I don't quite understand how a lean engine causes a backfire. Do you have any resources that explain this? I could try putting the stock airbox and carb assembly back on to see what happens but I cant get it to run on ether either so it might be some kind of vaccum leak on the intake side I do know that the manifold is intact though. Unfortunately I have already tried everything in the troubleshooting guide with no luck but now that I know that everything is mechanically in order it has to be my fuel and air or spark causing it to not run.

This is from Mikuni: https://www.mikuni.com/tg_backfires_in_exhaust.html

 

[jonlasaga]

I remade the all of the gaskets on the intake side and installed the manifold with shorter bolts the seal is very good all the way to the carb now. It sounded like it wanted to start second pull but I couldnt get it to fully start for me. I believe it is the spark plug or wire now. I will be replacing those today and seeing how that goes.

I also got new mikuni jets in the mail today so once I get it started I can troubleshoot my full throttle flooding issue.

Update: New plug and wire went on today and the engine actually started for me! I think the weak spark was my final issue but now It is running extremely rich and having very inconsistent revs for some reason but that will just need adjustment most likely. Thanks for all your help everyone.