So to start off my weekend I received a call from the BMW dealer telling me that the rewound stator is not producing sufficient voltage. At idle it is producing around 2.4V AC and at revs is gets up to ±9V AC. With the coils measuring correctly in terms of resistance and balance between the phases it seems the most likely culprit is the sequence or number of turns per pole of the stator. The magnets were checked and passed a visual inspection. Even on the old stator the one phase was giving ±20V AC on idle which supports the theory that the magnets are operating correctly.
I can take the stator back to the rewinder to get it redone but he would need an example to compare it with as his notes are obviously flawed. That can be arranged but the labour to remove and reinstall the stator is limiting my options. I do not have a test rig to confirm if the rewound stator is working so it would be another risk I'm taking to install the 2nd rewind and have the bike partially assembled to be able to start it again and test the complete generator.
At this point I also cannot leave the bike in spares at the BMW dealer, taking their space for too long. It has to be fixed or I need to collect the complete bike in spares and leave it in my garage for a while until I have a better plan. Most likely I will have to bite the bullet and pay for the original repair quote of ±R23k plus whatever labour the technician spent on this partial assembly, test and disassembly.
I'm sure there are some financial calculations available to decide on when to repair or replace a component, calculate the risk involved, the time value of money etc. but I thought that the risk was low enough for this to be taken as a viable option. The likelihood of success for my decision was never 100% but I felt at least 80% comfortable that is would work. Obviously you need to be prepared to suffer the consequences of the other 20% coming true, as it did for me.
I can only hope that the rest of the week will yield more positive results.
Regards
