2011 Suzuki RMZ 450 not wanting to fire up.

Fuel pump or dirty fuel filters.

Paw Paw

Paw Paw wrote:

Fuel pump or dirty fuel filters.

Paw Paw

This. Pull the fuel line and check if it's coming out smoothly.

Could be clogged up injectors as well.

I pulled fuel injector out and kicked bike over its spraying fuel. I can smell fuel trying to start bike. Tried different plugs also. Kicking bikes over with plug out it sparks blue.

If the injector is dirty and leaking it will make the fuel mix too rich at the first start up.
Try cleaning you injector.
Also, check your oil smell to see if it smells like gas. If so, the injector is leaking and causing the hard starting.
With you smelling fuel when you are attempting to start sure indicates a leaking injector.
Paw Paw

I just had injector cleaned plus I've tried another injector. I do not smell fuel in the oil nor does oil look diluted.

If your injector is spraying fuel, and you have spark and all your valves clearences are in spec
There should be no reason it's not starting. It could be a faulty tip over censor, but it has spark so that should eliminate the tip over censor . How much fuel is the injector spraying? Is it alot or barely enough to see?

6 hours on head/ valves? Preventative or did it blow up ? Bad starting just after rebuild done? If piston hit the valves the cam sprocket could have spun on the cam causing an ever so slight timing issue. Have had this happen myself and its hard to diagnose because timing looks correct but isnt.

Hey guys thanks for the responses. I just sent the head out to have it double checked. Valves are sealing! This could very well be a sensor. I was told by Vortex that these models are known for having bad wiring harnesses. I'm in the process of putting bike back together. I got a new MAP sensor and a new water temp sensor. The stator Ohms are in spec. I believe it's an electrical problem, but not sure where to start or how to test. Does anyone know how to test the Condenser?

Both mine and a friends 2011 450 had this problem (l posted an explanation back a few weeks ago here), turned out to be the blue/white (l think?) wire terminal in the plug that goes into the ECU. The wire is the ignition coil wire, because it pulls tight on the wire harness, it is the first to get pulled out.

l pushed the wire pin socket back in with needle-nose pliers and got a hot glue gun to secure it in. Bike never misses a beat now and they both start first kick hot or cold.

http://www.vitalmx.com/forums/Moto-Related,20/RMZ450-lost-spark-problem-solved,1311838

Oh it was quite a ways back, sorry :-)

Johnny89superbike thanks for the post I'll check that out. How did you find this? Can you tell from the top looking at the pins or did you find it from underneath at the wires?

1st, l had recently had the ECU off to fit a CRF steering damper.
2nd, l called a local ECU expert, he said very rare for an ECU failure, normally bad pin contact in the plug.
3rd, Sometimes when l pulled the ECU plug in hard by hand l would get an occassional spark at the sparkplug.
4th, The workshop manual shows the blue/white wire from the ECU goes to the ignition coil.

With those clues l went looking, found the blue/white wire had been pulled back out of the plug, pushed it in, starts first kick and has not missed a beat for over a year. My friends went after mine, we went straight to it :-)

Johnny89superbike- I see the wire your talking about, but all of mine seem secure.

Your name says new to 4s. Are you touching the throttle while starting? You will flood it that way. If you are indeed new to 4 strokes, just kick it from the top of the compression stroke. No gas needed.

Acidreamer I'm not new to four strokes any longer. When I signed up I was. Yeah I know the starting procedure. This is a new problem. My bikes never started super easy but this is something I've just recently had problems where bike will not start at all.

So the bike has no spark at the sparkplug?

Johnny89superbike wrote:

So the bike has no spark at the sparkplug?

Yeah that's what it looks like or it's real weak. Stator tests good. Got a new MAP sensor and temp sensor just haven't had time to mess with bike lately. Just pulled plug and kicked over hand wasn't seeing much spark. Not sure if I was turning it over quick enough. I'm thinking maybe my Condenser went bad? Thoughts?

Check the coil mounts for dirt and or rust.
Also check the kill switch.

Paw Paw

Paw Paw wrote:

Check the coil mounts for dirt and or rust.
Also check the kill switch.

Paw Paw

Thanks I will!

ls the ECU still mounted on the headstem?

Johnny89superbike wrote:

ls the ECU still mounted on the headstem?

Yes

CHeck the wiring my friend had a problem where the harness plugs in at the steering head. on of the wired broke at the connector. couldn't see it without very close inspection.

hassbeen wrote:

CHeck the wiring my friend had a problem where the harness plugs in at the steering head. on of the wired broke at the connector. couldn't see it without very close inspection.

Thanks I have some parts coming to swap out and see what's going on. It's been erratic that's for sure. That's why I thought it was the ECU when I swapped them out it would start, but my ECU tested fine.

Can you let us know what the problem was when you find it, thanks :-)

Johnny89superbike wrote:

Can you let us know what the problem was when you find it, thanks :-)

I sure will! Switching some parts right now. Haven't had time to work on it till now.

Guys still haven’t found the problem. Just ordered a new wiring harness. A guy I know gave me some parts to swap out. The wiring harnesses he gave me actually looked worse than mine, so i don’t know . Changing wiring harness on the advice of some of the industry people I’ve spoken to. I’m thinking I might have a stator problem. I had a very hard time getting OHM readings from the plug. When I was able to get them they were in spec, but it shouldn’t have been that hard to get readings with the meters needles.

Hmmm, as you say "checking the stator shouldn't be that difficult"? Maybe take it to a shop and get them to do it?

One other thing I did with my RMZ is I ground/filed the outer plastic surround of the wiring plug that plugs into the ECU so that the pins went further into their matching plugs. I then taped around the join to make sure it was water-tight. Our local ECU expert told me that on some models the pins don't have enough penetration (and you know that can be a problem ;-) ), it did appear so with mine.

I check in here everyday to see how you are going :-)

Johnny89superbike wrote:

Hmmm, as you say "checking the stator shouldn't be that difficult"? Maybe take it to a shop and get them to do it?

One other thing I did with my RMZ is I ground/filed the outer plastic surround of the wiring plug that plugs into the ECU so that the pins went further into their matching plugs. I then taped around the join to make sure it was water-tight. Our local ECU expert told me that on some models the pins don't have enough penetration (and you know that can be a problem ;-) ), it did appear so with mine.

I check in here everyday to see how you are going :-)

Johnny I’m not sure the wiring harness has even shipped yet, so it might be a week or two. I sent my Vortex ECU back to Australia and I Can tell you that is a wonderful Company to work with. My Vortex is well out of Warranty yet they still tested it for me and Richard Murrling of the Company has been outstanding. He is the one that has told me these bikes are known for wiring harness issues and he also led me to Jamie Ellis of Twisted Development as Richard had trained Jamie on the Vortex programming. I shipped my Head Cams and caps bolted down and Throttle body to Jamie to double check. The head and throttle body Jamie found no issues with. They cleaned my injector replaced both the temp sensor and IAP sensor on throttle body and head. After all this was done bike still won’t fire? I reached out yesterday to Ricky Stator but have yet to hear back from them. Johnny how far did you file down the ECU plug?

l only filed it 1 to 2 mm.