Ok, So i posted this on the 851 forum also Checked the charging last night and doesn’t look good on the M1R bike. Bear in mind I’d done about 10 miles in the dark on my first run out on the bike last week and lights getting dimmer. Checked battery voltage last night, 11.75v I started it and didn’t go above 11.75v at 3k, left it on a CTEK today, will try it again, could be it was flat and charging heavily, tho a 10 mile run would have been sufficicent. Battery obviously ok. When the R/R goes do they fail to regulate (voltage goes high), or do they go open circuit (no voltage) Had a read on the forum posts, late last night but it mentioned two wires from the generator. So is it a 3 phase system, but the 1 phase is effectively ground? Or is it a single phase? Any common issues to check? Haven’t even looked yet, but have a spares bike to swap bits over short term! I think I have a Honda R/R too, I could maybe graft that on if required It has a battery light on the 851, this wasn't on all the time on the 10 mile run in the dark, just when ticking over. On a car alternator the the battery light is important as it excites the windings in the alternator. With out the bulb [or if it blows] the charging cyctem will work, but not at tickover, only at 3k and up. Is the system on the 851 the same, does the bulb excite the windings? Any help appreciated. I have strong electrical knowledge, just not really aware how this system works, tho I plan to pull the lot to bits tonight to find out! DOH, can't edit my spelling mistake in the thread title, I can spell, just can't proof read
Hi mate, Single phase genny. Check the ohms on the windings on genny Other than that check all connections but i bet it's the rec/reg unit (common)
Not 100% sure but I think the system is similar to the same as installed in Guzzis of the same vintage. Unlike your car explanation which looks like it refers to an electro magnetic based excitation where the output is regulated by a varying DC feed to the field, this is a permanent magnet system. This means that for any given RPM the output is constant and all the excess output has to dumped as heat through the reg rec. Permanent magnet system is simpler so more reliable and cheaper to build but it does have the drawback of giving reg/recs a hard time. Chances are its the reg/rec that's thrown in the towel. As you suggest checks best done with the battery fully charged, but I would have expected the volts to rise a little when you revved it. You could check the alternator by taking the 2 wires off the alternator and measuring the phase voltage in AC I'd expect it to rise to 40V or greater AC. Other checks would be stator and rotor resistances although I don't have a manual to tell what these should be. Again if its like the Guzzi then usually the reg/rec just craps out and it stops charging. Hopefully shouldn't be too difficult to trouble shoot. Regarding using the Honda reg/rec you'd need to make sure the alternator has the same number of phases on the Honda, that its designed for a permanent magnet type alternator and that it could take the load. That's about all I got John
the Honda one will be 3 phase, but that's no issue, it just means that a number of the diodes inside the rectifer side won't be used. So I'd just insulate the unused 3rd phase. i'll do some digging tonight and post my findings, as you said tho, trouble shooting isn't tricky.
