Another reg/rect question

A couple of riders have commented on my front headlight being really dim. It may be a 35/50w bulb and I think it's wired (installed?) backwards to the hi/lo switch. I have noticed it gets significantly brighter when the engine revs. I have done some electrical modifications including the coil wiring mod and installing a 80's electric ignition. It seems to me there probably isn't much slack in the electrical system. The engine is a B1 type with three wires coming off the stator. I've gone through with contact cleaner and cleaned just about everything except the bundle in the headlight. I'm wondering if a modern 3 phase reg/rect will help make the most of the juice the stator puts out. I'm contemplating a h4 headlight setup but that won't really help on an already lean electrical system. I haven't tested the reg/rect yet but I've read that there's little that can go wrong with these stators.

I'll refer you to:
kzrider.com/forum/4-electrical/525274-h4-headlight-conversion

Use the search function and you'll find some spirited discussions concerning the electrics and the stators on the older, smaller displacement bikes. I recall something about upgrading them to the 3 phase to resolve the weak output and there was talk about the regulator/rectifier that goes with it.
Best of luck!

Well, the kz650 B1 has a three phase dynamo though I dont know it's relative strength or weakness. It was an odd design for the time. Excited field coil or something. I performed the tests my manual recommended for my rectifier and had a hard time getting any readings at all. Searches seem to point to regulators being a weak link, I should check that out too.

I recall the lack of permanent magnets in the dynamo was a key point. Your dynamo has to have a properly functioning battery (which relies on a properly functioning reg/rec) in order for it to produce voltage correctly. There are replacement stators out there designed to put out more current than the OEM in order to get over this weakness but I wouldn't trust the original regulator or rectifier with the higher output stator. The combo reg/rect units are better able to handle the increased input.

The 1000 didn't have this problem but I still replaced the harnesses with new, new fuse box, combo reg/rect, cleaned and or replaced the grounds, did the coil power mod and installed solid state flasher units, now I don't have any issues. The bike starts immediately every time and all lights work correctly.

Debating over the H4 or some other headlight as mine is dimmer than I care for because it's got the ancient Stanley headlight still in there.

The 77 KZ650 charging system uses a field coil to provide the magnetism. The alternator is plenty strong as long as everything is in working order, and the alternator is maintenace free... no brushes etc to maintain.

However, the regulator is mechanical and does need maintenance. the contacs should be cleaned if they are burned, and you may have to adjust the voltage by bending a tab (refer to manual for details).

In my opinion, you can do yourself a big favor by converting the regulator to a solid state type. OregonMotorcycleParts.com has a good one at a good price. But you will want to make sure the rest of the caharging system is working properly per the manual.

I went the route of just replacing my rectifier and regulator. Oregon Motorcycle Parts has great stuff and it plugs right in. No modifications necessary.

Before I upgraded, my charging system would be fine one ride...then no juice the next (dim lights) then back up to strength the next ride.

Now, constant 14.5 volts all the time.


Will

Holy kawberries batman I just totally enawesomed my bike! I grabbed ye olde analog multi-meter and measured the rectifier again and everything was right on spec. (digi meter read diodes as open?) So I recleaned the contacts to the regulator. I popped the hombre open and cleaned the contacts on the points. The contacts for position 1 (low rpm or off) were extremely kruddy. I checked all the resistances and they were on spec. I put it all back together, which was the biggest pita of the procedure. When I fired up the bike dang that light was brighter than I had ever seen. There was only a little popping and sputtering on warm up. And warm up was short! Only a couple minutes instead of the almost 10 I'm used to. I've been chasing an electrical gremlin for a while and I think I just caught the biggest one!

Mechanical voltage regulator, that crazy 70's technology! I'm so used to solid state, I didn't even think it could be that big of a problem.

I would recomend the solid state replacement as well. I did mine years ago and never even thought of looking back. It's not to expensive, and the solid state units are maintenance free.

Cheers!

Tom

That's great news. I like to hear the outcome, usually guys just disappear and we never find out if anything we recommended worked!