2013 RMZ 450 Fuel? Issues

So here's the story:

Bikes running fantastic, started 1st kick at the start of the day. I come into the pits, hit the kill switch. Go to re-start the bike and it just sounds dead/empty. Not even trying to start. So here's everything I've done so far.

-Pulled the kill switch, i know kill switches die easily, so i started there while still at the track, didn't fix anything.

-Checked the valves and compression, all is great there, nothing wrong with the motor.

-Checked for spark, the bike has a very strong visible spark.

-Pulled the fuel tank, did a run test on the fuel pump, well surpasses the minimum fuel output requirement.

-Pulled the fuel injector, visibly is clean.

I'm stumped, not sure where to go? The manual isn't very clear about the fi system diagnosis, as to what steps to start with. Anyone have any clues where to start?

Check timing? 

58 minutes ago, BDubb106 said:

Check timing? 

I have not. But I would think I would've known if it jumped timing while I was riding? It ran great. As soon as I hit the kill switch in the pits is when it died.

It will run just fine if it only jumped one tooth. If you bump start it you would never know that it jumped time, but you can kick it till your leg falls off and it wont turn over.

1 hour ago, BDubb106 said:

It will run just fine if it only jumped one tooth. If you bump start it you would never know that it jumped time, but you can kick it till your leg falls off and it wont turn over.

Interesting, I will have to check that tomorrow.

On 8/6/2017 at 11:01 PM, BDubb106 said:

It will run just fine if it only jumped one tooth. If you bump start it you would never know that it jumped time, but you can kick it till your leg falls off and it wont turn over.

So it's been a few days since I've updated. Here's what I've found thus far.

-The bike did NOT jump timing, thankfully.

-The bike does have good, strong spark still

-The fuel injector is opening and closing, i tested by hooking it up to a 9 volt battery, you can clearly hear the clicks of it opening and closing

-If you hotwire the fuel pump to the same 9 volt battery, the bike will start and run, poorly, but it will run.

-The fuel pump is getting 3 volts of power when kicking it, probably why it's not getting fuel/fuel pressure

-The rectifier is working properly.

-The magneto charges 24 volts when kicking, suzukis spec is 100v at 5000rpm....I'm going to assume that the magneto is working properly

-According to the manual I believe the fuel pump relay is built into the ECM. It seems as if the ECM is where the voltage is being lost. 

So I'm wondering if anyone has a way to test the ECM/fuel pump relay? It's not listed in the manual sadly. The bike is definitely not getting fuel, and it's not the injector. It seems to be fuel pump voltage. I'd like to know exactly why before I go drop a few hundred on a new ECM.

I've ran all the EFI tests and everything passes. All the electrical system tests it passes. The motor has good compression, valves are good, spark is good. Bike doesn't run. I'm at a loss.

I am having the same issue with my bike and just made a post about the same issue. I have been going in circles with the bike for over a week now.

The plug on the loom to the fuel pump fails a lot, make sure that is making really good connection, testing the fuel pump won't show this fault because from the plug back every thing will test normal 

Guys, come to find out it was my ecm. Here's the best way to run the test to see if your fuel pump relay is broken on your ecm. Hook a 9 volt battery to the service coupler. At which point your fuel pump should start running. If it does not, backprobe a lead to the ecm probe number 10 (red with black wire) and ground to the frame, if the fuel pump turns on, your fuel pump relay is bad. 

9 minutes ago, Fade said:

Guys, come to find out it was my ecm. Here's the best way to run the test to see if your fuel pump relay is broken on your ecm. Hook a 9 volt battery to the service coupler. At which point your fuel pump should start running. If it does not, backprobe a lead to the ecm probe number 10 (red with black wire) and ground to the frame, if the fuel pump turns on, your fuel pump relay is bad. 

It's good to see that you were able to diagnose the problem. Electrical issues are very frustrating. How did you figure out the 9 volt battery test?

39 minutes ago, Dklassen said:

It's good to see that you were able to diagnose the problem. Electrical issues are very frustrating. How did you figure out the 9 volt battery test?

Well the manual outlines tests with a 12 volt battery. I didn't feel like taking the 12 volt out of my truck or buying one, so instead I just hooked up a 9 volt. I figured if all I'm doing is checking that voltage is getting where it needs, who cares if it's 9 or 12 volts. Some tests like TPS sensor adjustment need a 12 volt though. 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now