| Author | Message | ||
     Coastrambler |
Been thinking on how the stator and voltage regulator fail. It just seems like it's not yet fully understood. So here's a sequence that occurred to me. In the 2009 model alternator output was increased by 100 watts and the failures began. The voltage regulator then had to dump that additional wattage, heating it up. Stator also runs hotter. Both due to regulator being a total loss shunt type. Regulator overheats and a phase fails. Stator will then be supplying power from only 2 phases causing it more stress. Thus leading to its failure. Any thoughts? I used to be in this failure analysis stuff for a living. | ||
| Froggy |
The only thing that is the issue is cooling of the stator. The stock configuration does not allow enough oil flow at low RPMs to cool the stator, and it overheats and fails. Running over 5000RPMs and you will not have an issue as it has sufficient cooling then. The EBR rotor modification allows oil to be jetted onto the stator to cool it off. When the stator fails, it typically has only lost one of the three legs, but because of how it works (AC), it effectively becomes a single phase stator. It uses legs A-B, A-C, and B-C for each phase, if leg C fails, you only have 1/3 of your output from phase A-B. The relay harness works by switching the bike between single and three phase to keep the stator cooler. Voltage regulators are often replaced as part of misdiagnosis, their failure rate is on par with virtually any other stock bike. More expensive aftermarket ones like the CE605 are indeed better and are better for the stator, but not really necessary. | ||
| Coastrambler |
Not convinced on that Froggy. The Buell "Fix" opened a leg. A shorted phase in the VR would wipe out 2 phases and be a high level load that would fry a stator. More thoughts. My current stator and VR lasted 18,000 miles. This with no heat sink grease on the VR to mounting plate interface. Both are currently failed. I live in a fairly mild climate. Many motorcycles use the shunt type VR. Have heard stories of Hondas & Ducaties having stator & VR problems. Most bikes have the VR mounted out in the wind, not inside where air flow is poor. My other bikes have had 1 VR failure & no stator failures in 230,000 miles, aggragate. It just seems like there's a system problem. |
