Is the electric fuel pump suposed to always have power to it and running the whole time?

 

No, there is a fuel cut relay that recieves a signal from the ignition system when spark is produced allows electricity to flow to the fuel pump. So if you have no spark, your fuel pump won't work either. The relay is located in the black box behind the right rear tire.

 

If you need troubleshooting details on the fuel pump circuit I can give them to you. Bad fuel pumps on that model are not uncommon, and I've seen a couple relays fail also, as well as the much simpler blown fuse. But most likely when you fix your spark problem your fuel supply system will work fine.

 

Would a faulty relay or poor spark cause hard starting--excessive cranking to get it to fire related to this fuel pump?? Where is this fuel pump located??

 

A faulty fuel cut relay would cause it to run out of gas, never seen it effect the ignition system. The fuel pump is just to the right of the carb. I see you have a trx250 SDK, They don't have a pump or relay and are a simple gravity feed. I'm not sure I understood your question.

 

The guy I'm fixing this for had it running, but didn't have the fuel pump properly working. He had this mickey mouse setup where he had a big car battery held onto the back of the 4 wheeler with these taped on wires going straight from teh fuel pump to the battery. He would hook this up to the battery everytime he's about to use the 4 wheeler. I understand where this relay is. Could you give me the troubleshooting details so I can have this resolved before I'm done fixing it?

 

Sure seth22. First off you must have a good battery hooked up, gas in the tank and the fuel valve turned on. Unplug the fuel cut relay, you can't test it directly. Turn the key on and probe the black\brown and green for battery voltage, with green being the ground, you should have it. If not, check the fuse, and make sure the green wire has continuity to ground. If your voltage is good here, drain the carb (or your pump won't run period) via the flatblade screw on the bottem of the carb, leave it open and put a suitable container underneath the machine to catch the gas if you want. Bend a paper clip in half and short the black\brown and black\blue wires of the cut relay coupler. Turn the key on. Your pump should click and gas should run out the drain of the carb. If it doesn't run, go directly to the fuel pump bullet connectors on the right side of the airbox, make sure they're plugged in. If they are, most likely your fuel pump is faulty. You can also apply 12vdc directly to the pump to check it. The pumps CAN fail intermittently, sometimes if you tap it with the back of a screwdriver it'll start to work (for a while anyway). If the pump works when you paperclip those wires, you can assume your power supply and pump is working fine. The fourth wire to the cut relay is a black\yellow, which ends up at the cdi coupler. When the relay reads a signal on that wire, it closes the same ciruit you did with the paper clip. So...if you don't have the spark signal to the relay from your cdi, the pump won't pump. This signal is difficult to read with a meter. If you have spark, and your pump works when you clip the wires, unplug the cdi and the relay coupler and check for continuity between the black\yellow wires. If you have it, the fuel cut relay is bad. Whew...hope that makes sense.

 

Alright. Thanks

 

Well this thread started as an '86 fourtrax question. That is what I have. A 2wd baby utility. Is he talking about a sport 250? That is why I asked about the fuel pump. As far as I knew, mine was only gravity feed like you say. Should they not be the same? Or is he talking about something different than what I have?

 

Your right SDK, I knew seth had an 86 TRX350 from a previous post. It DOES have an electric fuel pump because of the location of the fuel tank underneath the seat. It's the only Honda ATV I can think of that does. All other models, including newer ones, are simple gravity feed.