Strange that Zane Laverdas use basically the same reg/rect as late 1990's Ducatis, and yet don't have a reputation for them dying. Could that be because the wiring is made to a better standard ( apart from the starting circuit ) and the reg/rect is placed away from anything that generates heat? To answer the OP - two reasons : they get hot - because of where Ducati located them, and they wiring connections corrode, hence creating high resistance joints which damages the reg/rect. And yes, Electrex ones work well and seem to last much longer than OEM ones.
Seems to me you are treating the symptoms, not the causes. If you've fried 5 in ten years, I would suggest that the cause is somewhere in the rest of the bike, not in the reg/rect. Something is making them fail. Hondas, in general, are pretty much 100% reliable and they are not known for dodgy electrics...
If you are going to fit an extra heatsink/plate use heat conductive paste between the mating surfaces, it will give better thermal transfer.
I used a whole tube of that stuff for CPU's. Thermaline Silver something or other. Have plenty about as I tend to build my own PC's as I am a cheap fucker. Fucking messy it was though.
Get yourself off to your nearest Maplins and buy an aerosol of silicon grease then spray that into the connector and once it's back together use some self amalgamating tape around the joint. No moisture will ever get past that little barrier. I use the same trick on every connection I can get at on the Tenere and the only bit of loving care it gets after that is hosing down with ACF50.
Have to agree with you there Hammer, I think I paid about £120 from memory for my RR53 Electrix unit around 18months ago and now thats fuct too.......not impressed with rip off Britain piece of shit...... bike sat for over 6 months without turning a wheel so didnt last as long as original fitted to bike, 13 or so years for Ducati part..... Ive already changed connectors for a better type and use thermal grease as Bootsam does. Due to time constraint as Im getting bike ready for a trackday at Cadwell on Tuesday Ive purchased a new unit off ebay for £29 pounds...... cant be any worse than the shit Electrix unit.... Will fit Zx10 unit and harness as Chris W suggests in future. Daz.
You have never heard of Hondas frying rec/recs? VFRs and some CBRs are famous for it, have a look on google. The 03/04 600RR is well known for killing rec/recs, as they mounted them right next to the exhaust manifold and it boils them. The 05/06 remounted them elsewhere with a heat shield in place, now retrofitted to mine, so far has been good for years. The reason I went through so many is that the replacements electrex kept sending me under warranty were naff. Live and learn.
The Electrex on my 851 has a 25mA leak back through it when swirched off. The Electrex checklist seems to say that up to 50mA is acceptable. Trouble is it flattened my new LiFePo4 Ballistic battery and now it does not hold a charge. I now have a second hand MOSFET regulator and the Triumph cable and need to get another battery. Mike
Triumph had some issues with reg/revs on early bikes where it was located on the back of the crank case by the rear shock, they moved it to under the right-hand handlebar fairing where it got more air and then replaced the unit for a different model in 2009-2010. They even recalled loads of bikes not long ago for replacements. Honda VFR's were known for it also, I would say its mainly a heat thing. My dads mate has fitted a CPU cooling fan to his on the VFR and not had a problem
had similar experience, the 'everything turned off' leakage of some Electrex are typically typically 4 times the amount of the standard units and can get larger in time. As said earlier I think both the earlier Ducati Energia and later Shindengen units get an unfair pasting, often being targeted incorrectly.
Mike of course that 'leakback' is not an issue when the bike is running, but is going to discharge the battery when it's not! Only thing I can think of is a battery isolation switch fitted in circuit, so as you could disconnect the battery when the bikes engine is not running.
I suppose my luck will change if I mention this, but out of all the bikes I have owned, the only reg/rec I have ever had fail was on a 250 Francis Barnett in the late 60s. I have had this SS for four years now without any reg/rec bother.. (touch wood)....its an RR51. AL
I agree with Chris on this one, the later model 748/9xx Shindenghen regs are perfectly ok and we have both discussed this on and off on the boards for a few years. Unless the connectors are 100% the resistance created (as little as 0.5ohms) generates heat at the AC plug contacts and causes a downward spiral of resistance and more heat and it is this effect which causes the regs to over heat due to the increase in electrical loads and imbalance of the AC phases in the AC side of the circuit. If the connectors are not clean, very tight and water proofed then the regulator followed by the windings of the stator will fail. I maintain that the location, whilst not ideal, is not the primary reason for most failures - it is deteriorating contacts in the plug. Best thing to do is cut them out and replace them or simply cut them out and solder the wires through. By all means add heat sinks, move the regulator and certainly maintain the battery to avoid bulk charging it from the bikes generator. But if you don't sort out the connectors you are probably going to have a break down.
A late entry on this but my findings: It seems to me that the output from the 900 type or even 916 996 748 alternator is quite high, high enough to melt the cables or the reg rec or both, this problem does not seem to happen on the 750 or 600 that has the same reg rec cables, and windings, the only difference on these bikes is the rotor, the rotor is slightly smaller by about 6mm in width so I fitted one of these and made a spacer to take up the extra clearance and bingo! all good, charges the batt perfectly (as all the 750's do) and probably liberates a little of the power lost from the alternator. of course this only applies to the early single phase bikes. There is no difference in the way anything operates electrically, just that the ability for the reg rec and cables to cope with the slightly reduced load, when you consider that once the battery is up to voltage the excess energy is dumped as heat from the reg reg so expect these to get VERY HOT! if these are not getting hot you have another problem. don't confuse the system that Ducati use with other bikes that use electrically exited windings where these can be switched off when power is not required, Ducatis just don't work like that, both the three phase and single phase systems dump the energy as heat at the RR. you still need to keep all the connectors clean and tight.
Problem wiring is still there even when rectifier is replaced, IMHO I think there is nothing wrong with either its just the output is too much from the larger alternator single phase bikes. The original rectifier was fitter to the laverda twins, these also had smaller windings as the 600 and 750 had. I feel this is the main reason for ducati changing to the three phase system. Of course, another good fix but greatly reduced output (about 300w) is to fit the small race rotor as fitted to the early race endurance bikes, these were still good enough to run lights and the electronics but with marginal battery charging, these rotors were used on the 888 and 916 but also same rotor fitted to early st2 models, super small!
