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-   -   Motor Quits at Low RPM's (http://www.hdforums.com/forum/showthread.php?t=232684)

Tbones 05-12-2008 10:37 PM

Motor Quits at Low RPM's
 
I did a search of the forums so forgive me if this problem has been asked before and answered. My bike runs good when I going down the road, no problems but when I deaccelerate and get down to less that 2000 rpm's the motor just quits. It starts right back up again so I'm thinking that the battery is getting a weak cell in it. It's the same battery that came with the bike. It is a 05 VRSCB. Anybody experience this themselves? Only thing I did before and after was install a Series 5000 Dakota speedo, can't imagine that has anything to do with it but who knows. Like I said, I'm leaning towards the battery being weak and as long as the rpm's are up the voltage output is enough to keep the motor running. Was just wondering if anyone else has had this problem and it was the battery. I don't believe it's the fuel pump that is a possibility too. Thanks.

Vrod Mike 05-12-2008 11:15 PM

RE: Motor Quits at Low RPM's
 
It's not the battery. Even if the battery were completely dead the alternator in the bike can run everything without the battery. To me it sounds like a fuel problem. The older bikes are know to have faulty fuel flanges so I would start there.

NightStar 05-13-2008 10:54 AM

RE: Motor Quits at Low RPM's
 
At 2 to 3k rpms the engine will lug. This isn't what you may be referring to? Otherwise I agree it is most likely a fuel delivery problem.

Tbones 05-13-2008 01:56 PM

RE: Motor Quits at Low RPM's
 
Nightstar - No, it's not lugging as I have the clutch in. It just dies like it is out of fuel yet it will start right back up again and then will idle fine. Using my logic, I look at what the bike was doing before I made changes as compared to what it is doing now. Before I installed the new speedo from Dakota, the bike did not die, now it is.

Both the instructions that came with the gauge and the Harley manual have the wrong color coding for the wires coming out of the VSS switch to the transmission. The instructions call for splicing into the "white" wire coming from the VSS sensor with the green wire going to the gauge. That did nothing. Dragging out the manual for my year V-Rod (Harley manual), the wire diagram shows white, red black wire coming out of the sensor when in reality the wires are black, black/blue and black/light green.

The black/blue wire is the correct wire to splice into. I talked to the folks at Dakota about this and they knew that the wire color to tie into was black/blue and confessed that their instruction sheet was wrong. Now, having said all this brings me back to what the bike is doing which leads me more to electrical rather then fuel delivery. However, they both are connected. The fuel system is run by the ECM which in turn is powered by the battery. I'm wondering now by splicing into the wrong wires damaged the ECM or is sending the wrong data to the ECM and then to the speedo or the map settings in the Power Commander has been screwed up by hooking this gauge up.

My trask turbo should be in shipping today along with a new map for my PC III. Nick Trask suggests that when Thudermax comes out with its system for the V-Rod to seriously take a look at installing it over the PC III or the SERT. My gauge is working properly and the bike runs good above 2000 rpm's however, I have noticed a different vibration coming from the bike. Which makes me think that the PC is somehow messed up after this gauge installation and hopefully with the new map coming from Trask will help clear this issue up. I will probably go ahead and replace the battery as it is three years old and this past winter did not hold a charge like it used to which suggests that the cells are getting weak. I don't agree with Mike that the bike will run fine with just the alternator because the alternator puts out AC and needs to be converted to DC by the regulator/rectifier which in turns regulates between 13 to 15 volts dc to the battery and the rest of the electrical circuits in the bike. I do know that if the DC voltage drops below 12 volts it will effect the ECM.

But, this could just be coinsidence and the fuel delivery system (fuel pump) just decided to go bad at the same time I installed the gauge :)... So who knows but, I'll figure it out sooner or later. I was just being lazy and was hoping that maybe someone else had experienced this and could take me from point A to point C without having to explore point B :)... Thanks for the replies, it is appreciated. When I find out what the problem is, I'll post it here. Thanks again.

eazy 05-13-2008 05:06 PM

RE: Motor Quits at Low RPM's
 
I would try isolating the possible problem by simply "removing" the Dakota speedometerand seeing how it runs with the wires disconnected.

Tbones 05-13-2008 10:56 PM

RE: Motor Quits at Low RPM's
 
eazy - yup, good suggestion. I was going to do that and load test the battery just to be sure the source isn't the problem. :) On the other hand, Trask emailed me today and my turbo is on the way, should be here by Friday. That's a full day install so I'll do the other stuff at the same time and see what happens :) Thanks for the help.

Tbones 05-14-2008 03:42 PM

RE: Motor Quits at Low RPM's
 
Vrod Mike - The more I dig into this, the more it points to what you suggested is the problem with the flange. Thanks for the tip Mike, it is appreciated. I will look at this flange/fuel pumpwhen I install the turbo and replace it if needed which sounds like I probably will have to replace it. A friend of mine who also owns a V-Rod told me what to look for if the flange is the problem. Thanks again.

agapsdiver 05-31-2008 06:52 PM

RE: Motor Quits at Low RPM's
 

Make sure your air filter isn't dirty.

Hal64hd 06-01-2008 03:37 AM

RE: Motor Quits at Low RPM's
 
The fuel flange problem was on earlier V rods 02-03 I would find the problem first before the turbo install

Billydj 06-01-2008 09:30 AM

RE: Motor Quits at Low RPM's
 
Tbones,

Look at this:

http://www.v-mod.com/tech_home.aspregarding the retun line fitting. Don't know if it applies to 05s but they offer a way to check if you have this issue. I may have this issue on my ride. Anyone know what year/bike this applies to?

Ride Safe...
BillyD


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