I have a starting issue, this bike has a new aftermarket , fuel pump but it runs all the time when key is on, is this normal? An bike has only been sitting about 4 months, so tried to start it an it hits an try's ..but won't fire up, it won't even try to start if I turn the throttle, only if choke is on all the way... But I was told bike has a tip over relay, is this true? An if so which relay is it. That controls the fuel pump? So yes it sounds like maybe I have more then one problem, please help

 

I have heard another issue maybe on this site about the fuel pump staying running while only the key is on. I am going with the fuel pump relay is faulty. Thats job is to prime the pump, then switch off untill the bike starts and runs to be back running. It is not normal for it to stay running with just the key on.

What do you mean it wont even try? You hit the button and just nothing happens? It clicks? An open throttle, combined with a choke is going to flood the engine, on top of it it is going to cut the air supply and creating lower pressure to pull even more fuel to the engine. TO me that is saying that there is a lot of fuel and nothing igniting it. Typically if you were to hold the throttle wide open and choke this is where you are going to get your highest chance of ignition because what happens is it creates a very rich mixture that is required because cold fuel cannot vaporize fast enough. With all of that said,

Are you sure you are getting spark? Pull a plug and first check if its wet with fuel, (wipe the plug off) then check for spark. Make sure they are. IF one is they probably all are but make sure they are.

I believe they do not have a BAS. There is a Fuel cut relay however. It looks like a plastic rectangle. Here is a fiche you can look at to trace the wiring to its location. I cannot tell you where it is on the F4. Follow the wiring or check the color on the wiring coming out of the tank and check on your CDI or around your main harness for the same color wiring, there you will find your relay.

YOu have to check the main three on your Carbed bike. Spark, Air, Fuel.

Do you have a manual?

Report back about the spark, then we will proceed.

 

Possiblef4I, what I meant by it won't even try lol, is that when I push start button, an try to give it a little bit of throttle, it won't hit, but when I choke it all the way an crank it it, it try's to run then quits...but yes when I turn the key on, the aftermarket fuel pump runs an never stops, I found out that it was wired to key power only... an not the relay, so now I hooked it up to the relay I found on the right rear of the frame, there was a plug not in use, so I used a test light an connected it, so now when you turn key on pump goes on real quick an goes back off..an the relay clicks when this happens. Is this normal, cause bike still doesn't want to start :/ an also I have replaced all plugs, an I do have fire on them.

 

Yes, that is normal, the clicking is signifying proper operation. The pump will prime the system, then turn off untill the bike starts. Good to see you got that sorted at least. Pretty much rules out fuel pump.

Say Im a little confused. Trying to give a little bit of throttle the bike just cranks as in the pistons are moving? And then with choke you say it tries to run? Because to me this is the same thing. Unless you mean with choke it still cranks but sounds different? Its going to with a choke on, you are limiting the air supply into the engine. Choking sounds boggy and more unsteady than a non choke situation. So which is it?

We need to differentiate the two. It is going to help in diagnosis.

Do me a favor. Prop up the tank, get to the carbs, and fire some starting fluid into the carbs while cranking, see if that starts it. Carb cleaner will do the same thing. You do not need a lot, just a little bit will do the trick, its not about getting it to run for a awhile, just to see if it will catch and start. Process of elimination.

Oh and try both ways, with the petcock/fuel off, and with it on, and report back what happens for you.

How soaked are the plugs? Even if you replaced them recently you can still foul them by delivering improper a/f mixture to the cylinders. We are attempting to eliminate the fuel delivery system as one of the potential reasons its not starting.

Ever have any trouble with the CDI on the bike as well? Not sure your level of knowledge based on mechanics either. If you know the basics of an engine and etc, then some of these things may be common sense or you have tried already.

-Poss

 

Lol...I do under stand what you mean, I do feel that the plugs may be fouled, because of this fuel pump being wired incorrectly, as to what I was saying though just with the choke on all the way, the bike tries to run a little, but if I try to give it any throttle it dies, while doing this...hope you understand what I'm trying to explain, but I will get back to you after I've freshened the plugs up, an also I will do the starting fluid test...thanks for your help

 

Ok I have everything hooked up on the bike far as fuel pump, an bike is trying to run, but I have to keep using the choke, for it to run but it will not stay running with choke turned off...you can hear fuel pump running when you push starter button an engine is cranking. An starting fluid keeps it running, when I spray it in the breather, so it seems as if it is starving for gas...so I have removed carbs an have them on the table, an float bowls have been removed, there is some varnish is all four carbs, but all bowls had gas in them :/ so now in continuing on the the low speed jets, an going to examine the throttle diaphragms now...this is my brother in laws bike so I'm just trying to get it running right again...if you have anything you would like to add, or what else I should look for while I have the carbs apart I'm all ears lol...one more thing...this fuel pump reads it makes 7lbs of pressure, is this what this bike should have to run?

 

how was the fuel level sensor hooked up? The bike wont start unless the leads are plugged in correctly. Have you downloaded a service manual yet? They have an extensive troubleshooting guide on getting the bike running. I would trace the fuel and see if it is backed up anywhere, is the tank clean of derbies how does the fuel filter look? have you tried removing the fuel pump all together? The bike can run without the fuel pump if need be. You said it was an aftermarket pump are you sure it has the right flow rate to satisfy the bike? Are all the vacuum lines hooked up correctly?

 

DId you treat the fuel before it sat for 4 months, or was there fuel in tank? If no fuel in tank, did you just fill tank and go?

4 months with untreated gas could be bad gas in it. Not much or no gas in it could have made the tank rust. In turn some of that could of plugged up the fuel filter or hose along the way. You said its getting fuel in the bowls but Im suspect now because perhaps its not getting enough fuel? Pretty much saying what Jardine said. But go back through from the carbs back while you have access to the hoses and check the line back to the tank.

Sounds like its getting fuel, just not enough perhaps. This would explain it starting with full choke and dying when applying throttle. Apart from that, checking the carbs to make sure they are delivering the fuel properly sounds like youre on the right track.

From what I understand you are saying its starting somewhat with choke so if its turning over then that would mean its not sensor??

 

Thank you CJardine, for your input ...you did hit some pretty good things to check, but yes I've checked them the fuel filter is also new, it came on the new fuel pump an I replaced all the fuel line...an it had no fuel in the tank when parked, but the carbs was not drained...so I knew this upon trying to start the bike, but when I add new fuel to the tank I just figured it would run an be ok...all vacuum lines seem to be in great shape, an they all was in tacked...so now I am going to continue on with cleaning the carbs tomorrow, an checking for cracks in the intake boots...Ido you guys know of a service manual PDF or any links on here? I do know that this bike run good before an the fuel pump that was on it then is the same kind that was put back on it, but it is evident that they don't last long.

 

F4 Service Manual