New rider need help

[Meta]

Hello everyone im in desperate need of help so last year I bought a 2022 RE classic 350 reborn signals and its been an amazing bike even got my motorcycle license with it on my first try however recently it doesn't seem to want to start and looks to be back firing through the intake. I've already made a couple repairs on it such as rebuilding and cleaning starter as it seems they didn't install a lock washer and one of the the screw came loose. New fuel in tank and repaired the spark plug wire(thank you squirrels)so now the sparkplug gets spark, fuel pump works and doesn't seem to be clogged at all i even charged the battery and even got a new one. I checked all the fuses and relays. Even checked to see if the exhaust is clogged but nothing. Any ideas are much appreciated on what the issue could be

 

[vectinterceptor]

Squirrels, check the air filter .

 

[Meta]

Squirrels, check the air filter .

I did still looks brand new also even with starting fluid it doesn't want to turn over thinking it my be the valve lash, ecu, or wiring

 

[nmroadrunner]

Swap out the relays to rule out a bad one.

 

[Meta]

Swap out the relays to rule out a bad one.

Thanks will do and just checked the injector wire with a voltage meter and it came out to only 2-3 volts which it's supposed to be 12v right? Just asking cause i wanna make sure im not mistaken ol

 

[severely]

I did still looks brand new also even with starting fluid it doesn't want to turn over thinking it my be the valve lash, ecu, or wiring

Welcome from Texas. I'm thinking tight valves, good luck.

 

[Roy Gavin]

Backfiring through the intake might be a clue , but if it is tight valves it might have been doing it before you switched off last time.
But easy to check and eliminate.
Other possibility is ignition timing, the ECU needs decent volts to perform properly, so if you can check voltage at power input do it.
Relays can affect this , as previous advice, again easy to eliminate, and will probably need to be done sometime..
The procedure for checking voltage at the injector will be in the factory manual- I have a carbed bike so can't help there!
Other possibility is a air leak between the injector and the head - when my size twelves kick one of the carbs loose on my BMW the result can be the same backfire!

 

[Stig57]

Have you checked all the wiring ? if you are only getting 2-3 v when it should be 12 there's either something causing the voltage drop or there's a poor connection.
I'd start at the battery, main harness connectors (one red, one black), clean and replace the relays, check the connector under the tank as it can come loose and the ecu connector.
If you can get hold of an OBD2 reader then that may also help and should give any fault codes.

 

[Alan F.]

I would first measure battery voltage with key off and key on, it wouldn't be the first new battery to cause issues. Also make sure battery connections are both tight.