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Discussion Starter #1
Friends, My 2004 RC 51 will not start after minor maintenance this winter. It was running fine when I put it away. The motorcycle has 11,000 miles and the only modification is a Power Commander.

Maintenance:
1. Oil and filter change.
2. Drain and replace coolant (all panels and front cowl are off).
3. New brake pads and bleed brakes.
4. New spark plugs (removed and replaced tank).
5. Inspected and cleaned air filters (PO installed K&N).

Symptoms:
1. I hear the fuel pump start when I place the key on and also when I cycle the kill switch.
2. I sprayed a little starting fluid in the front intake and it runs for a few seconds. I therefore conclude I don't have an ignition problem.
3. I checked fuel pump recirculate flow by removing the 5/16 hose at the recirc valve and fuel flows when the pump is turned on via the ignition and cycling the kill switch.
4. I checked for pinched hoses under the fuel tank.
5. I have tried starting with the cold circuit (choke) both engaged and disengaged.

I will truly appreciate trouble shooting guidance.

Thank you

K Rayna
 

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Discussion Starter #2
Additional Information

1. I took the air cleaner cover off and when starting there is not fuel injected in the aft cylinder. I can only see down the aft cylinder.

2. The cutoff relay at the right rear of the motorcycle "clicks" when I turn the key on and off.

3. One other condition the headlights and turn signals are disconnected due to the front cowl being off.

Again, I would appreciate any input. I am studying the service manual and will tackle the problem tomorrow.

KRR
 

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Discussion Starter #4
Mr. Quizzy,

I agree I need to check the simple things. I am trying to figure out which interlocks affect fuel delivery to the injectors since the starter is working along with the spark (runs if I put a little gas in the throttle body) and the fuel pump is pumping. I also have fuel exiting the return line from the pressure regulating valve but I am suspecting the pressure is not getting to the injectors.

Still working on it and welcome all suggestions.

KRR
 

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Headlights and signals unhooked shouldn't affect anything.
Have you bypassed your PC and tried to start?
The connectors are just under the left rear of the fuel tank, tucked on the inside of the frame.
The other switches you mentioned about checking are bank angle switch and sensor, neutral switch, sidestand switch, and clutch switch.
I believe if your fuel pump is working, and you're getting fire at the plugs, and it runs on ether, then all of the above switches are working properly. imo.
From what you described, (which is cool that you list all the things you've already done), it sounds like the injectors just aren't getting the signal to hit.
I don't really know that area well enough to advise, but your switches are probably ok.
 

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Discussion Starter #6
Mr. Jondog9, Thank you for your input. It is very early and I am planning my activities. I do not know what the acronym PC stands for. Please define so I can pursue bypassing it.

Thank you

KRR
 

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Also check with a multi meter for signal at the injectors. If you do have the injectors tested.
 

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Discussion Starter #10
It Runs! It Runs! It Runs! THANK YOU

From the title you can deduce success. I will give you the story:

1. I checked for power at the injectors: None
2. I looked at the Power Commander (PC) and noted no lights turned on. I never looked at it but noticed green lights apparently indicating the speed of something. (I don't have a manual for the PC but will soon get one.)
3. I traced the wiring harness of the PC and found a small (about 20 gauge) ground wire adrift with a copper colored spade. I don't know where it was attached but I connected to the ground of the battery.
4. Turned the key on, fuel pump primed, green light on the PC, Nickey started!

I ran it up to temperature as I just replaced the coolant with Engine Ice. Obviously I am happy!

I want to thank everyone who contributed to this post and all the people who previously had this problem as I was able to study their troubleshooting. I hope I can contribute to others in this RC51 forum some way.

Again THANK YOU!

KRR

PS RC51s sure sound sweet!
 

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So the bike will still run if I disconnect the power commander?
Should I unplug it from under the tank or take the positive lead off the battery?
 

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So the bike will still run if I disconnect the power commander?
Should I unplug it from under the tank or take the positive lead off the battery?
Usually, if there is a PC hooked up, there may be issues with the disconnecting of it and running the engine for any amount of time since it will no doubt be running lean without the PC connected.

err on the side of CAUTION when running an engine without the PC connected !!

Just my 2 cents worth on the subject
 

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So the bike will still run if I disconnect the power commander?
Yes, since the Power Commander is an aftermarket piece that did not come from the factory ... but you need to take the Power Commander out of the circuit ... read on ...

Should I unplug it from under the tank or take the positive lead off the battery?
Unplug it from under the tank. The way the Power Commander is installed, you separate the OEM connector's male and female halves under the tank and then insert the Power Commander, which has connectors that mate to the OEM connectors. So ... you can easily disconnect those 2 connections and reconnect the OEM connector back together.

Not 100% sure, but I think if you only disconnect the Power Commander's positive lead off the battery, I don't think the bike will run ... and I think it's for the same reason it won't run when the Power Commander's ground lead has come disconnected or even just corroded.
 

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That's a little bit confusing. Should I switch the two connectors? Or just disconnect the PC?
When troubleshooting, remove the Power Commander from the bike. That way it can't cause you any problems. If it turns out not to be the problem, you can easily plug it right back in.

It's guess it's because the Power Commander seems like an 'innocent' little plug-n-play thing that it doesn't always dawn on dudes that it's an aftermarket item and that since aftermarket items are often the cause of problems it should be one of the first things removed from the system when troubleshooting.
 

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Yes, since the Power Commander is an aftermarket piece that did not come from the factory ... but you need to take the Power Commander out of the circuit ... read on ...



Unplug it from under the tank. The way the Power Commander is installed, you separate the OEM connector's male and female halves under the tank and then insert the Power Commander, which has connectors that mate to the OEM connectors. So ... you can easily disconnect those 2 connections and reconnect the OEM connector back together.

Not 100% sure, but I think if you only disconnect the Power Commander's positive lead off the battery, I don't think the bike will run ... and I think it's for the same reason it won't run when the Power Commander's ground lead has come disconnected or even just corroded.
Just reinforcing what Extrap has already mentioned.
Unplug the main harness connectors under the gas tank. There's four of them. Figure out which are the PC connectors and which are the ECU connectors. Plug the 2 ECU connectors together, and leave the 2 PC connectors unplugged. (No need to remove the PC from the bike.)
The only wire from the PC that goes to the battery, is the NEGATIVE ground. It's a ground only, no need to unhook it.
As far as I know, Power Commanders get all their power from the bike's harness that you just unplugged.

As mentioned, the bike will run decent, but now you're running on the OEM fuel map, it may be lean, depending on your exhaust setup and/or internal engine mods.
fwiw, I unhooked my PC some 300 miles from home once, and rode it the whole way like that. Only mod was a set of Yosh exhaust cans and mids. The bike ran fine. When I got back home, I figured out the problem, hooked the PC back up, and been running it ever since. That was about 4 years ago.
 
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