Charging - what to consider

[Bixxer Bob]

Ok, this is a little premature because I've not actually ridden the damn thing yet but I thought I'd start roughing out what could become a link in the knowledge base.

I've had some issues with my Girly over the last year or so.  The worst being it not ticking over when coming to a halt. It would just wind down the revs till it stopped, often with a nasty kickback on the sprang.  Even when it did occasionally tick over, it was lumpy and it had some backfiring on the overrun.  I was constantly looking for air leaks thinking that was the probable cause. That or an iffy IACV.

I also blamed corrupt trim files or maps although this was based on previous experience when the battery gave up and seems to bear out now.  I fitted a voltmeter ages ago and have always since suspected my reg rec was not as it should be, but even on runs of a couple of hundred miles it never let me down with a flat battery.  The volts were around 13v on tickover dropping to 12 - 12.3 higher up the revs.  A couple of months ago I did the Sasquatch mod to see if it helped. I then had too many volts, around 15.1v so decided I wanted to try a MOSFET reg/rec.  (Quick simplified explanation, the original Triumph reg/rec takes the AC output from the stator, turns it into DC, charges the battery and turns the unwanted volts left over into heat. A MOSFET is much more efficient and monitors the battery level intelligently then provides only the volts needed to keep the battery charged so generates much less heat, which is the eventual killer of reg/recs).

I fitted the MOSFET today, it's plug and play, but take care to clean / replace any suspect connectors. Some folks solder the connections instead of using the connectors. While in there I changed the way it's mounted. I've always thought the standard mount with the fins vertical was the worst possible way to mount something that needs airflow to keep it cool. I made a small bracket and mounted it with the fins horizontal thus making the most of air flowing past.  It fits ok and doesn't interfere with the battery box or tank.

When I started her up, she ran better and smoother than she has done for a long time and with 14.6 volts regardless of what the engine is doing or what is switched on.  I have some ideas as to what is going on here but will save them till after I've put a few miles on her.  It got me thinking back though because sometimes it would run well immediately after doing some work but revert to normal after a few miles.  I thought this was the ECU trimming back to crap after I spent hours tweeking it. But it might have had more to do with me routinely charging the battery while off the bike.  We'll see.....

[DavidR8]

Interestingly enough, my 06 ran much better with a fresh battery, very crisp throttle response and a nice steady idle. I don't think I have a R/R problem so far as I never see less than 13.1v at the battery.

[Bixxer Bob]

Well, what can I say   70 mile jaunt this morning. Bike ran better than it has for ages    14-14.7v cold, 13.6-14.6v hot, stock 10173 map, fairly smooth at 2.5-3000rpm (not perfect but more than happy with it), small amount of popping on overrun but nothing disturbing. Only slight niggle is the tickover is still a bit low.  It sits at 1000-1150 but still sounds on the verge of stalling.  Only actually stopped on me once, just after zi filled up, then it was fine.  Think I'll check the tank for water next time its empty.

Edit: it was actually just BEFORE I filled up when it stopped; which is what made me think maybe water.  I put in 21.5 litres so close to where I found water the last time. No more stalling after that, but coukd do with a few more revs at tickover.