stevestever 0 Posted October 12, 2022 My TRX 420 will crank, but not start. I drained and replaced the fuel, replaced the spark plug. There is not gas on the spark plug. I removed the gas line from the injector thinking if I tried to start it and the pump is working, fuel should come out. None did. I hear a click and low hum when I turn on the key. Now I'm thinking maybe the fuel pump relay? I've see this can be a problem with these atv's. Can anyone give me a clue where the relay would be? I searched replacement parts and cant seem to find what I saw pictured. Any help would be greatly appreciated. Share this post Link to post Share on other sites
shadetree 5,543 Posted October 12, 2022 20 minutes ago, stevestever said: My TRX 420 will crank, but not start. I drained and replaced the fuel, replaced the spark plug. There is not gas on the spark plug. I removed the gas line from the injector thinking if I tried to start it and the pump is working, fuel should come out. None did. I hear a click and low hum when I turn on the key. Now I'm thinking maybe the fuel pump relay? I've see this can be a problem with these atv's. Can anyone give me a clue where the relay would be? I searched replacement parts and cant seem to find what I saw pictured. Any help would be greatly appreciated. the relay will be back near the battery. the 420's are prone to bad fuel pumps. Share this post Link to post Share on other sites
jeepwm69 7,223 Posted October 12, 2022 Welcome aboard. Shot of starter fluid in the intake fire it off? If so, run a jumper wire from the + on the battery to the red/black wire on the coil (just pull the connector back a hair so you can get the jumper wire on the terminal, don't unplug the wire) If it doesn't run then, either your fuel pump is shot (likely) or your injector is clogged. If it's been sitting, especially with ethanol gas in it, fuel pump is likely seized. Share this post Link to post Share on other sites
toodeep 1,733 Posted October 12, 2022 The 2019/2020 had an update for the fuel pump but if yours is a 2021 model it wouldn't be in that. The relays are under the tank cover and I would have to look in the manual to determine which one is for the fuel pump. If you can hear the fuel pump hum when you turn the key on it should be getting power though and that would make me think fuel pump. Checking the power going to the fuel pump would confirm that. 1 Share this post Link to post Share on other sites
Charlie 11 Posted October 12, 2022 Even though the recall doesn't seem to include the 2021 models, I would call your dealer or Honda just in case, as you just never know . Honda Fuel Pump Recall.pdf 2 Share this post Link to post Share on other sites
stevestever 0 Posted October 12, 2022 Found the relay, and it seems to be getting power. We are going to look at the fuel pump tonight and see if it is seized. Thanks for the comments. Share this post Link to post Share on other sites
