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Bike running strange.


LogoMan

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Hard to explain...the exhaust note has changed at idle. New battery and bike starts like a champ, but then dies sometimes. I have a stumble that comes and goes at steady throttle noticeable at 5K rpm. Bike running kind of rough at low rpm. Finally gets going around 3k rpm and runs like a scalded dog. The FI seems more touchy than usual to inputs.

cudgel says to check the coil wires and then the spark plug wires.

I've never changed the fuel filter. The air filter probably needs to be changed but I haven't checked. I run good gas and use Techron or Seafoam in the gas every now and then.

What say you all?

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I'd be suspicious of that "new" battery... and load test it. Was it fully bench charged prior to installation? The kind of erratic running symptoms you've described can easily be attributed to a battery issue (e.g., adequate surface charge, but insufficient actual capacity). The fact that it's the only thing that's been recently changed merits a close look...

Never overlook the simple or obvious stuff. Most gremlins are usually far more simple than we tend to imagine - don't let the frustration factor fuel conceivable fixes. That can unnecessarily exacerbate any problem.

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Ditto on the Fuel Pressure Regulator. I've read more and more posts on the slow deterioration of the FPR diaphram due to 10% ethanol gas. My 2000 started to idle somewhat roughly, and sure enough, the FPR was failing. This can dump raw gas into your crankcase, so check it. It's an easy replacement and only costs $40-$60 depending on the supplier.

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The battery was properly charged and this was going on before I changed the battery.

I believe it started right after I bumped the rev limiter on a pass. It sounded and ran differently after that.

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It might be wise to still check your grounds and load test the battery... If it's not electrical - assuming the R/R is OK - I'm leaning more toward a fuel delivery issue. As tomek and Supermarine already mentioned, the FPR seems to be increasingly problematic (likely thanks to alcohol laced fuels), and thus the weak link in the fuel chain. As far as I know, fuel pump failures are exceedingly rare; so I'd start looking for the usual FPR symptomatic tell-tales (ragged running, flooding, periodic loss of spark in one or more cylinders, raw fuel in the vent lines, etc.).

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I ordered a Turbo City FPR last night. I think you guys are on the right path with the fuel issue diag. Hey, it's got to be spark or fuel, right?

Hope the TC FPR is worth the money over stock or I'm an all day sucker.

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Relax, it's only money.

Now you will be an all day rider.

All day rider...what are you saying? :icon_biggrin: Which reminds me...I need some beads.

I'll let you know how the TC FPR goes.

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  • 2 weeks later...
The TC FPR transformed the bike. Nice! Wish I'd made this change sooner.

How did it transform your bike? I'm having the same issue now and I've narrowed it down to the FPR...but $40 vs $129...Is it really worth it?

I haven't done a side-by-side comparison, but the bike SEEMS to run better than it ever did. The FI sensitivity is gone for one. Also seems to have more meat in the midrange and it really rips as the revs climb. I find myself riding a lot faster than I used to.

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