#19 PostAuthor: Al » Tue Apr 04, 2023 9:41 am
So its been a few years now and time for an update / evaluation.
I would strongly recommend not tightening the centre fixing bolt to standard J 1000 / GPz1100 torque of 116 Ft / lbs. Where 85 or 90 Ft / lbs is more than enough.
If you over tighten the centre bolt it forces the mounting core part up the taper and stretches it or even splits it. You will then lock the centre core carrying the starter clutch free wheel to the inboard end of the crank by pinching the needle roller bearing against the washer that lives there and binding the freewheel.
That leads onto the magnet part (sleeve). This is a close 'push fit' over the mounting core part. If you stretch the core part you will damage / stretch the magnet sleeve. These are neodymium (rare earth metal) re-constituted / compressed powder (not ferrite) into the appropriate shape as far as i know. Circular in this case. They are potentially fragile and need no excuse to break. They are also currently £90. They are susceptible to; heating and cooling cycles, shock and impacts and also damaged by moisture. All the things you will find in a old bike motor on the end of a crank at 10,000 RPM spinning round in emulsified oil! Mine has been perfect for five + years now and i am only finding this out as of about a few weeks ago; un-covering a low charging / low voltage problem and the cascade of issues which have flowed from that!
I e-mailed Electrex last month and they said that they had tried un-successfully to re-charge the magnets and replacement was the only viable alternative. To re-charge Neodymium magnets you place them in contact with another of the same type; North pole to North pole and South to South. Problem is these sleeves have 8 poles arranged radially around the sleeve so difficult to work on would be an understatement.
As an aside, this setup has been good for me but i would suggest anyone using a low power unit like this uses caution with an electronic setup like Dyna 2000. Dyna 'S' would be perfect as it has no specific voltage requirements, but Dyna 2000 like mine, has a 'minimum' reference voltage for the crank end pickups. At low RPM it makes about 12 Volts but there is a 1.5 volt drop across the Dyna 2000 ECU which means that at low revs, it looses its ability to read its own map (advance curve). The instructions if there are any recommend that the output from the very expensive (to replace) Shendingen Reg / Rec is run directly to the battery terminals. This means that battery voltage / system voltage is what the reg/ Rec voltage is and fluctuates with RPM. However that wasnt blatently apparent for the years to now. There were 'hints' along the way under specific scenarios like when the battery was low or prolonged periods on low throttle but for the most part; something you could easily 'ride around'.
The blurb says you can run all sorts of fuel injection, ancilliaries, fairy lights etc etc but are they subject to a 'drop dead' voltage requirement; i cant say.
The standard centre bolt is too long and needs cutting down, gasket needs re-shaping, plug needs making for oilway, might need to add a washer, the rubber damper for the freewheel has had to be skimmed by approx. 2 mm etc etc etc.
For five plus years it was money well spent, now its a bit older.......questionable....... but i'd probably do it again as the benefits are substantial.
AL
1981 J1
