GT250A wiring Qs

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daxman
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GT250A wiring Qs

Post by daxman »

Hi All

1) I've found and tested the diodes on my rectifier, but where is the regulator? should be on the end of red/green wire I think but I can't find it..

2) On the wiring diagram it shows the lhs handlebar switches connected to 'loom part 2' by a single 9-way connector, mine though appears to have individual bullet connectors, some original some nasty 'red' ones. Any idea what's correct?

Cheers

J
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Alan H
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Re: GT250A wiring Qs

Post by Alan H »

Exact position no idea, and it seems that it works to limit the AC current from the alternator by leaking it to earth?
Without knowing what's in the regulator itself (diode/resistor etc?) I can't be more specific, but daresay you need one or the bulbs wont last long and the battery will boil if it's run at high revs for long periods.
Have a look near the rear brake light switch - they might make the positions on the diagram relevant to the positions on the bike.
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Re: GT250A wiring Qs

Post by dollydog »

hi dax, it should have the 9 pin connector, readily available you know where and they do fit well - very tight. the 250a does have a regulator, although the earlier model just has a rectifier and uses the battery as a regulator [don't ask]. try one of the solid state reg/recs, they work well enough.
https://www.ebay.co.uk/itm/9-pin-2-8mm- ... rk:14:pf:0" onclick="window.open(this.href);return false;
these fit perfectly and you'll only have to wire one half up :D
cheers, dd.
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
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Alan H
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Re: GT250A wiring Qs

Post by Alan H »

That would depend on the type of regulator. The Suzy triple type uses a contactor/relay that introduces a resistor to the rotor of a three phase alternator. The rectifier is a 6 diode unit, not the more normal 4 diode unit for an alternator of the 250 type. Different system altogether.
I have no details of the type of regulator used on the 250.
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tz375
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Re: GT250A wiring Qs

Post by tz375 »

edit: .
Last edited by tz375 on Fri Feb 01, 2019 10:29 pm, edited 1 time in total.
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Re: GT250A wiring Qs

Post by Vintageman »

The regulator is under the seat where the front of seat mounting lip is held on by frame horizontal bracket.


look at 9 sec into video. Its has a silverish metal rectangular shape

https://www.youtube.com/watch?v=wZStjU-EGT8" onclick="window.open(this.href);return false;
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jabcb
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Re: GT250A wiring Qs

Post by jabcb »

Your bike has a single phase alternator with a lighting coil.

You will get a smidgen more current out of the alternator plus much better voltage control if you upgrade to a modern rectifier/regulator. You can then use a modern maintenance free or AGM battery.

That is what we did on a T500 & the GT250 cafe build. I can provide the details if you are interested.
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daxman
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Re: GT250A wiring Qs

Post by daxman »

Hi All

Thanks for all the great info. Looking at the youtube clip it seems I don't have one (regulator)! This bike is throwing up more an more mysteries from its past - no wonder the guy was prepared to give it away! Have ordered a nine-way connect or too so will hopefully fix that part. God knows where the loom came from because several of the nine had original bullet connectors :?

Cheers

James
daxman
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Re: GT250A wiring Qs

Post by daxman »

Well I doubt I'll be buying a new one!
https://www.ebay.co.uk/itm/Suzuki-32500 ... 7020822707" onclick="window.open(this.href);return false; :shock:
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Re: GT250A wiring Qs

Post by dollydog »

hang fire there dax, i think i've got one of them in my spares. pm me and i'll get back to you tomorrow. out most of today, so i'll deffo sort it in the morning - provided i can get in the [frozen] shed doors :D there's one of them in there somewhere and i don't need it.
cheers, dd.
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
daxman
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Re: GT250A wiring Qs

Post by daxman »

Many thanks for the offer. If you can find one let me know. I think i would prefer that than try to wire in a modern reg/rec.
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Re: GT250A wiring Qs

Post by dollydog »

hi dax, i found it, but mine is the rs21/06 and has 3 wires coming off it instead of 2. green wire which goes to earth. yellow is from the alternator and tees off to the light switch. black is 12v from the ignition switch. if you don't want it, try this: https://www.ebay.co.uk/itm/163507327857" onclick="window.open(this.href);return false; the same as yours.
cheers, dd.
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
alanr
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Re: GT250A wiring Qs

Post by alanr »

somebodies hacked your wiring loom,be prepared for endless trouble.been there,best solution is new loom and reg,rec combo.
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daxman
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Re: GT250A wiring Qs

Post by daxman »

alanr wrote:somebodies hacked your wiring loom,be prepared for endless trouble.been there,best solution is new loom and reg,rec combo.
The loom doesn't look that bad. I've got some nicer period-style bullet connectors and also a nine-way on order so I think I can repair it without to much hassle. I have had the thing running too. reg/rec combos are cheap as chip on'bay but any recommendations would be good.

Note that bike is being recommissioned in a 'survivor' style. Low-cost functional trumps cosmetic and authentic in this case.
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Re: GT250A wiring Qs

Post by jabcb »

I’ve used a Tympanium rectifier/regulator on several bikes. Its popular with the vintage Triumph guys. Its around $50 but several other companies sell the same R/R for a bit less.
If you are unsure about a R/R that is available in the UK, then post a link to it.

This is how I mounted it on a T500:
Image
Did pretty much the same for a GT250 but only used 1 screw. You have to enlarge the R/R slot a bit because of the size of the battery box screw. The R/R housing is soft aluminum — just notch it enough for the screw with a file.
Make sure there is plenty of gap between the top of the battery & the screws.

More info for the T500 install is here:
download/file.php?id=420

For both the T500 & T250/GT250, I wire the lighting coil to be active all of the time. This bypasses the handlebar switch.
For the T250/GT250, see the 3rd wiring diagram here: viewtopic.php?f=29&t=6786&p=121472&hili ... or#p121472
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
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