[todd]

hello I have a late 80's fourtrax that uses a fuel pump to deliver fuel to carb. I have had problems with over fueling, had carb overhauled still same prob. fuel pump seems to run all the time and within a minute or so runs like crap and blows black smoke. Can disconnect wiring to fuel pump and runs good until it runs carb out of fuel. What turns the pump on or is it internaly regulated. Thanks Todd

 

[Pain]

Yes, it is regulated internally, at least mine was. When I bought my fourtrax, it has some aftermarket pump rigged on it, and I eventually replaced it with a used honda pump I got from ebay. The aftermarket rig worked, so you may be able to rig your own if you can't find a honda replacement and want to swap the pump.

 

[Helmut]

Welcome to the forums.

 

[submarine 300]

Welcome to the family.

 

[69quadracer]

Welcome to the forums! if it has a elec fuel pump than it should have a pressure regulator, sounds like a bad regulator.

 

[shadetree]

if you can't find a replacement pump....try this..and it works..been there..done that...go to advanced auto parts store..tell them you need a 12v dc fuel pump...your looking for one that has right around 4 psi..no more than that !..it works great !!..you will have to cut the old wire leads from your old pump..and splice them onto the new pump..then your good 2 go..oh..i'm not sure about your old pump having a internal regulator inside the fuel pump...i'm saying this..because my '89 trx350d foreman has a seperate box that controls the fuel pump pressure..it cuts the fuel off once it reaches so many psi..i'm not sure your bike has one..but i do know some atv's have them.

 

[Helmut]

if you can't find a replacement pump....try this..and it works..been there..done that...go to advanced auto parts store..tell them you need a 12v dc fuel pump...your looking for one that has right around 4 psi..no more than that !..it works great !!..you will have to cut the old wire leads from your old pump..and splice them onto the new pump..then your good 2 go..oh..i'm not sure about your old pump having a internal regulator inside the fuel pump...i'm saying this..because my '89 trx350d foreman has a seperate box that controls the fuel pump pressure..it cuts the fuel off once it reaches so many psi..i'm not sure your bike has one..but i do know some atv's have them.

Shadetree, I would say that his ATV is just like yours, Fourtrax 350, because those are the only ATVs that I know of from the late '80s that have an electric fuel pump. It could be a different year than yours, but I would say the fuel system is the same.

 

[shadetree]

if you can't find a replacement pump....try this..and it works..been there..done that...go to advanced auto parts store..tell them you need a 12v dc fuel pump...your looking for one that has right around 4 psi..no more than that !..it works great !!..you will have to cut the old wire leads from your old pump..and splice them onto the new pump..then your good 2 go..oh..i'm not sure about your old pump having a internal regulator inside the fuel pump...i'm saying this..because my '89 trx350d foreman has a seperate box that controls the fuel pump pressure..it cuts the fuel off once it reaches so many psi..i'm not sure your bike has one..but i do know some atv's have them.

Shadetree, I would say that his ATV is just like yours, Fourtrax 350, because those are the only ATVs that I know of from the late '80s that have an electric fuel pump. It could be a different year than yours, but I would say the fuel system is the same.

if thats the case..then there is a electric fuel pump relay box somehwere on his bike..that cut's the fuel pressure once it reaches a certain pressure..thats what mine does anyway.

 

[Helmut]

if you can't find a replacement pump....try this..and it works..been there..done that...go to advanced auto parts store..tell them you need a 12v dc fuel pump...your looking for one that has right around 4 psi..no more than that !..it works great !!..you will have to cut the old wire leads from your old pump..and splice them onto the new pump..then your good 2 go..oh..i'm not sure about your old pump having a internal regulator inside the fuel pump...i'm saying this..because my '89 trx350d foreman has a seperate box that controls the fuel pump pressure..it cuts the fuel off once it reaches so many psi..i'm not sure your bike has one..but i do know some atv's have them.

Shadetree, I would say that his ATV is just like yours, Fourtrax 350, because those are the only ATVs that I know of from the late '80s that have an electric fuel pump. It could be a different year than yours, but I would say the fuel system is the same.

if thats the case..then there is a electric fuel pump relay box somehwere on his bike..that cut's the fuel pressure once it reaches a certain pressure..thats what mine does anyway.

I would say his is the same.

 

[Pain]

Where is the pressure switch? I don't have a service manual for that machine any longer.

 

[shadetree]

Where is the pressure switch? I don't have a service manual for that machine any longer.

mine is on the back right side..inside a black box..with 4 screws..it sits next to the reg/rect above the right rear tire.

 

[Pain]

Strange. On my 86, the wires for the pump came from the front. Seems strange they would have the switch on the back and the wires in the harness coming from the front. Is your pump wired to that switch, or does it also have wires coming from the front of the machine, on the right side of the air box?

 

[Helmut]

Those Fourtrax 350's had quite a bit of wiring for an older bike. I remember having to trace down a short on one for one of my buddies a couple years ago.