Blown Reg/Rec.

[Chris H]

Hi all,
Im pritty hot with most things but have hit a brick wall with my B4 blowing reg/rec's. The bike is in mint condition so no old/repaired wiring, ive checked everything with a meter and everything shows good- earth, 70V ac at the genny and the bike starts, runs. Within a couple of days of running with a new reg/rec they stop putting out voltage and the battery runs down. Wonder if anyone else has been down the same road.
Chris.

[Dink_1170]

The generator is putting out 70VAC at what revs? is that across all three legs?? you actually need to check the output at a few points through the rev range; idle, 3000 rpm , 6000 rpm. cause 70 VAC at idle is high, especially as that would tend to indicate about 100 VAC at 6000 rpm, in which case the stator has open circuited and needs replacement or re-winding. BTW remove , clean and resecure every earth on the bike .

Dink

[Chris H]

Hi Dink,
Didnt want to type too much but 70V's is at 5000rpm as per manual, i get 29V at tick over and have not checked above- any ideas as too a max? Ive checked all the earths using the meter and am thinking it could be the stator or a possible short only when i push the starter altho im still figuring out how to test this. The bike was rebuilt from the ground and ran before so its going to be somthing ive done/not done but ive been over it with a fine comb.
Chris.

[Dink_1170]

Chris
70 VAC @ 5000rpm sounds low as does 29 VAC @ idle,do you have a manual?? I suggest going to this link http://www.thegsresources.com/gs_garage.htm and reading the stator papers. The easy way to test the starter short theory is to leave the multimeter leads connected across the battery, and watch the voltage drop, then repeat at the various connections through the starter circuit. Although IMNSHO your stator is crook.

Dink

[Chris H]

Hey Dink- it getts deeper!
Stripped the loom/connections recleaned and ran a nown good reg/rec loose and ok. Rebuilt, minus the tank and ok, 14.2V across the battry so fit tank and hey presto i got a miss fire/ weak spark. Must have a short so got to track it down. The big pain is as its a Variable valve model ive no diagram so will be working blind. Im a qualified electrician and still hate bike electrics.