2007 GasGas Will Not Start- Need Help

I need help with my 2007 Gas Gas EC 450 FSR. It won't run. It has super low miles, but it sat for most of its life. I have installed a new fuel injector and throttle position sensor TPS. It gets great spark and appears to be injecting properly.
In starting attempts, it will backfire into the air filter, the smell of raw gas is extreme.
Sure could use some help from someone who knows these Gas Gas EFI four strokes 4T. I have a compression tester on the way to verify nothing happened to possibly cause an issue with an intake valve.

[@johnlocatelli1768]

I'm a retired mechanic and seem to gravitate to these testing jobs. Try this in the following order; drain all fuel and fill the tank to half with 98 octane (easier if you're lifting the tank on and off) , remove the spark plug and replace with a new NGK CR8E set the gap .7 - .8mm, remove the spark plug lead from the coil and check all connections - you need to be 100% certain there are no breaks or corrosion anywhere, unscrew the resistor at the spark plug connector and check, remove the air filter and attempt to start if it doesn't fire with a few cranks, stop and spray some starter spray directly into the air intake / throttle body with throttle wide open, then crank again if it fires on starter spray then it sounds like its staving for fuel and you'll need to look into the EFI starting with checking the fuel pressure I think 45 - 55 PSI but check the specs. Sounds like you know the drill... compression, fuel and spark. Hope this helps and good luck.

[@joshdixon5744]

Wow this is the best video I have ever seen in my entire life!

[@joshdixon5744]

Also I'm no help best of luck to you sir!

[@renzobartolotta6839]

Matto cycles in Pittsburgh got me all kinds of parts. I have an 03 ec450fse

[@paulsumner5564]

I had the same problem with a 2007 EC450 FSR I bought. I solved it by discovering that the short tube between the fuel pump and the fuel filter located in the fuel tank was perished and split. This was causing fuel starvation at low revs and starting.

[@scottdixon7891]

Update: After everything I tried, I replaced the spark plug for the third time with NGK resistor type and flushed out all the gasoline that was pretty new. Put non ethanol in it again octane 91 fresh from the pump and what in the world....it fired right up and runs pretty well. I rode it a couple of times since then probably adding about 80 miles to the bike. It seems to have a low rpm problem. It idles fine and runs ok with decent super low rpm chug but my old Honda XR350 had much better lug and chug and get up and go down low than it. So for a 450 I say it acts more like an old fashioned 125 2 stroke that comes alive in mid range. It greatly disappoints down low and finally gets to mid range where it hauls butt. Or maybe even better compare to a 1981 Yamaha IT250. So it still keeps me perplexed.

[@scottdixon7891]

Fresh gas yet again and another new plug and she runs pretty good but low on bottom end power. Sat all winter and started right up after a battery charge. Put about 100 miles on it running that way last season. Handles like a dream. Just had wimpy power until mid range then launched forward like a beast. Will see if I can get the low end power where it should be this go around. Suspect plug or fuel pump issue.

[@gracedixon5801]

This is a good vidio :)

[@joshdixon5744]

Wow I really agree with the intellectual perspective you have approtiatly shared with us

[@chriscameron6811]

Every figure it out?

[@camillevangeld3755]

Hello can someone send me photos from the wiring. I have the same bike convert to crossmotor. But I have no spark. I think it’s problem with the wiring there’s also no key with the bike so maybe I need to connect some cables? And I don’t know which wires I need to put on the batter. Someone please help

[@Mancavechannel]

Where do you find parts for the gas gas bikes? Can't seem to find any parts anywhere. I'm looking at getting one cheap used that needs parts possibly

[@renzobartolotta6839]

Matto cycles in Pittsburgh

[@panagiothsXiloudis]

Hello I have the same bike and the same problem also sometimes when i ride it powers off ..so I would like to know if you solve this problem and how..sincerely thank you!

[@dozicstevica9876]

Same problem. Please help

[@jormandy7]

Good fuel?