voltage dropping with revs ?

[zimm]

now i know that if the voltage rises above 15v when revving the bike (measured across batt terminals) then the reg/rec is goosed ..

but what if its reading @14.1v @ idle then drops to 13.5v when revved ?

[masterofinsanity]

have you got any lights or anything else on mate, i know when my rec went the battery voltage didn't rise when revved it just kept going down.

[zimm]

no lights fitted mate, was just checking my freshly hacked together race loom before i wrap it all up neatly.

soon as the revs drop back to idle its back at a happy 14.1-14.2

its supposed to be a new reg/rec on the bike (certainly looks it), and its a brand new gel battery

all the elctectrics were ok before.. except the battery kept dying.. thought it was reg/rec at first, but the battery (sealed type) wouldnt hold charge overnight so i wrote it off as a duff battery and bought a new one..

shame its nowhere near road-legal anymore or i'd just go for a blast and see how it is... then again, its still mot'd and insured ..

i'll go warm her up properly and check the alternator output, and reg/rec connections. Maybe i fried something running it with a flat battery for so long

[zimm]

can someone quickly clarify the alternator output testing procedure ..

in the manual it says to disconnect the plug that has the 3 wires coming from the elternator and check the voltage across any of these.. should be 43v ac .. however it also says to check "across the yellow wires" which .. um head to the reg/rec .. the ones disapearing into the genny being black ?

[masterofinsanity]

just looked in the L manual it says 43v across the black wires any less and the genny is shagged.

[RedexRobB]

does sound like it could be the generator assuming everything else related to the charging circuit it fine.

[zimm]

thanks for the help !

ripped the windings out ..

after getting .. um NO volts across the wires.. which is odd as it'll run with a flat battery in there and the spark has to be coming from somewhere*

looked a bit crusty in places , couple of burnt out wires, didnt look terminal, i've seen far worse come out of a running engine..

found a spare in a box of tat, cleaned it up in paraffin (covered in dust n muck) fitted it all up, and get normal (ish, my multimeter is a bit epileptic when it comes to AC) readings across the wires..

and a strong 14.blah v across the battery irrespective of revs.. however its still dropping off a touch when revved compared to idle .. maybe just battery flat ?

did try a spare reg/rec, all looked great for 20 seconds then the voltage shot to 16V ! thats gone in the bin.

*maybe doing this is what burnt the genny out ?

[zimm]

update !

after ragging the zx4 into town to collect a multimeter that actually works (last one couldnt decide where it wanted decimal places to be and was giving all manner of random readings .. its in the bin) ..... its fixed it .. 43v - 52 v ish .. across each pair .. well, at least i know the alternator's ok, just need to verify the reg/rec's doing as its meant to and its all good

now .. if only i had a battery charger i could use with a gel battery... i could see how well the battery voltage stabilises as it gets charged a bit ..

cant just run her up for half an hour, its got a triny radiator and no fan

but i do have an H2 radiator on its way.. which should help on that score.

[masterofinsanity]

zimm what does your bike look like? mad max 4??

[zimm]

um, it looks like a race prepped zxr400h1 with no bodywork on at the moment ..

oh, and an unfinished wiring loom ..

what colour should i paint it ?

provide the paint and stickers and i'll paint it any colour this forum decides ?

[masterofinsanity]

matt black.!!! green stripe to match the porsche ! did you sell it? swap for a celica?

[zimm]

i did think about it, but i've had a matt black and kwak green zxr



thought about painting the camper to match too .. and then decided that was a bit sad ..

matching car/camper/racebike/roadbike*

thought you sold the celica ?

the porsche is still here ..

been offered 215 quid !

i'd rather watch the paint fall off than waive goodbye for that amount of cash.. feckin tyres are worth more than that !

*currently the roadbike, is black frame/green panels

[masterofinsanity]

£215 they havin a laugh? if i hadn't got the celica i'd buy your porsche missus keeps going on about a new porsche the front doors getting old.

[zimm]

Im not really bothered.. apart from the fact i have nowhere to keep it (parked on pavement for the last month) i dont really want rid, and i could do with the motivation to get the van and the alfa running.

[MillaMeter]

what colour should i paint it ?

Just throwing ideas at ya