Tom
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Another tip. When in pairs of wires, like to the solenoid, you have a positive(input) and a negative (output). Usually, not always, but usually the brighter colour is positive the darker is negative. This will apply to stereos, houses, cars etc. Look at your home 240v power cables. Blue is brighter than brown, blue is positive and brown is negative.
Thank you Marcel.
Cpt – post a pic of the connector block and I will post you a replacement with instructions of how to replace the original (no special tools required) or just that bad pin incase you need it. Message me an address or I can send via site admin if necessary.
That connector block sounds like the issue, or a least one of the culprits.
This is the how I would check starter circuit if my GV had no solenoid click and no starter turning over but all lights etc work. Sorry for length.
1 give starter soleniod a fair tap with a 22mm spanner sized object and see if it tuned over. No luck then number 2
2 check voltage is reaching solenoid at its connector. Set cut off switch set to run and with starter button pressed. (select on meter DC voltage ’20’ put red probe in brightest coloured wire and black pobe on exposed frame metal/bolt/engine/battery neg post). No luck number 3
At this point you could feed 12v directly from batt down a old bit of wire to the solenoid. Because you have two wires connecting to solenoid the second will go need to go to ground (somewhere on frame/ batt neg). Just a quick touch of 12v will tell you if it is all good with solenoid and starter turns. The black wire is usually the negative/ground, I say ‘usually’ as I have seen all black wires with no labels before.
3 Fuse, is there 12v? Does 12v pass through fuse? (same proceedure select DC voltage ’20’ probe connections with red probe and black to neg/ground). You should have power here, if not trace back, if you have 12v do step 4.
4 Starter switch and engine cut out, because I have all lights and neutral I am assuming ignition switch is good. Undo the two screws clamping switch holder to handlebars. The throttle cable will be restricting access to the lower part, the top part will lift up enough to clearly see inside.
I would test the engine cut out first as I have easy access.
In photo below (different bike switches and horn side not starter but they are all pretty much the same inside) you will see red arrows, these point to the contacts inside the switches, they are very exposed. When you operate the switch you will see the switch internals move inside connecting/disconnecting. You also see the wires soldered to each switch, which gives you the colours when you have no wiring diagram – note the wire colours to each switch. With continuity selected (see photo below) hold the multimeter probes on the soldered wire contacts on the switch (if there are three wires to a switch the middle is usually the feed in and the outside two the two switch outputs). Test switch on and off positions with your multimeter. The meter will read ‘1’ or ‘OL’ for open circuit (switch off) and ‘0.0’ for closed circuit (switch on) . If in doubt of what reading is what set multimeter to continuity look at screen and touch probes together, touching probes is a closed circuit (switch on). Some multimeters beep with closed circuit which is great if yours does.
Now turn on ignition and see if 12v is present and passes through the switch. Set multimeter to DC voltage ’20’ and put black probe on frame metal whilst then touching red probe to each soldered wire contact in turn. Check On and Off positions. Screen should read around 12v.
If that cut off switch is fine then the starter button.
Wiggle throttle cable off throttle grip and expose lower switch case. Note wire colours. Again same test proceedure, check continuity with starter button pressed and released. Then check 12v.
5 Diagnosis.
– If I have 12v at fuse, and 0v at the switches but the switches show continuity then the issue is after the fuse and before the handlebar switches (ignition area/ conns/ wires).
– If I have 12v at switches, on and off have continuity and 12v passes through both of them then the issue is after the switches in the loom connectors or wires leading to soleniod.
– If I have 12v at only one switch but both switches show good continuity the issue lies in the connecter or cables of the handlebar switches you are working on. The 12v often passes through the first switch, back to the connector block where a spare pin is used to link two wires feeding the 12v back to the second switch. If there is no pin often it is two wires twisted/crimped together inside the wires sleeve/wrapping.
– If 12v reaches switch but not passing through (no continuity) then spray contacts with cleaner and move switch through On and Off 20 or so times and test again. If necessary repeat a few times, if no joy get new switches.
This photo is of left side pitbike switches but it will show you what to expect inside. I also put a multimeter with meanings to symbols. Red arows show exposed switch contacts.
That is how I would trace it in the loom. To test a wire you select continuity and put a probe on each end looking for the closed circuit. If you cannot get closed circuit wire is bad and replace.
To test conns, stick probe in one side contacting with the chosen connector pin. Do the same with the second probe on the corresponding connector pin on the other side of the connector, again looking for closed circuit. No continuity means bad pins.
Since the wire colours where noted and I know the order of the switches etc so I therefore know the direction the 12v starter signal in travelling in the loom. It is easy to chase that colour wire through the loom and connectors checking continuity as you go. The loom is not big and solenoid and battery placed central to the bike with switches up front, there can only be so many connectors and wires involved. If you get lost halfway through loom test from solenoid back to switch.
When using the meter’s probes often a layer of oxidisation/tarnish/dry flux will stop connection. You may have to scratch and dig a little to get contact. If in doubt select continuity and put both probes on the same contact, only touch the contact with probes not the other probe. Look for open and closed circuit, closed means you are getting a good connection.
Sorry for length, hope this helps and is not complete confusing waffle.
I did reply but it disappeared when I edited a spelling mistake.
So sorry if this duplicates it if it appears.
cptpickle I am sorry to hear that, electrics are a daunting subject that is actually very straight foward. You can do it and I can show you how, I am a qualified electrical engineer. The wiring loom and connectors can look like a big nasty birds nest wrapped in tape, you do not have to unravel the birds nest just test accessible bits of it.
You just need a simple multimeter for a £5 and some contact cleaning spray again about a £5. It should cost you nothing more to get starting circuit working and the spray will most likely cure the indicator gremlin. As you have said already the bike’s bolts were decayed badly, that means she has stood outside alot so some of the exposed wiring connectors and switches will be dirty and perhaps have some corrosion – easily fixed with the spray.
You will measure resistance if you have to test if wires and see if the connections are good (resistance shown by an solid triangle pointing to a vertical line or the ohms setting shown by an Omega symbol on the multimeter). For voltage being present you want use D/C current (a straight line with a dotted line below – A/C is a wavey line). You would use A/C settings to test output from some stators before the rectifier – your stator works fine.
You have an earthed negative frame that is always the negative connected straight to the negative on the battery via a fat copper wire. This makes it easy using a multimeter as any exposed metal (engine case / frame bolts etc) is an earthing point(negative) for the multimeter. To track electrical faults is a methodical task but not difficult one.
I have a GV with all the same wiring, wire colours etc and can post pics on where and what to check. Also Marcel has seen almost every issue with Hyosung, he will help.
I will see if I can track down a wiring diagram for the GT/GTR, this will give us an easy guide to follow with wire colours and routes etc.
You have already overcome the largest problem and the starting circuit is just a minor wrinkle in the whole show. Most people would run away at the thought of an engine change – hellfire, you did it first time and it runs!
If you sell on now you will give somebody a bike that you fixed all but one or two very minor issues. They will quickly clean the connections and be quids in
You can do this – easily!
cptpickle I am sorry to hear that, electrics are a daunting subject that is actually very straight foward. You can do it and I can show you how, I am a qualified electrical engineer. The wiring loom and connectors can look like a big nasty birds nest wrapped in tape, you do not have to unravel the birds nest just test accessible bits of it.
You just need a simple multimeter for a £5 and some contact cleaning spray again about a £5. It should cost you nothing more to get starting circuit working and the spray will most likely cure the indicator gremlin. As you have said already the bike’s bolts were decayed badly, that means she has stood outside alot so some of the exposed wiring connectors and switches will be dirty and perhaps have some corrosion – easily fixed with the spray.
You will measure resistance if you have to test if wires and see if the connections are good (resistance shown by an solid triangle pointing to a vertical line or the ohms setting shown by an Omega symbol on the multimeter). For voltage being present you want use D/C current (a straight line with a dotted line below – A/C is a wavey line). You would use A/C settings to test output from some stators before the rectifier – your stator works fine.
You have an earthed negative frame that is always the negative connected straight to the negative on the battery via a fat copper wire. This makes it easy using a multimeter as any exposed metal (engine case / frame bolts etc) is an earthing point(negative) for the multimeter. To track electrical faults is a methodical task but not difficult one.
I have a GV with all the same wiring, wire colours etc and can post pics on where and what to check. Also Marcel has seen almost every issue with Hyosung, he always helps.
I will see if I can track down a wiring diagram for the GT/GTR, this will give us an easy guide to follow with wire colours and routes etc.
You have already overcome the largest problem and the starting circuit is just a minor wrinkle in the whole show. Most people would run away at the thought of an engine change – hellfire, you did it first time and it runs!
If you sell on now you will give somebody a bike that you fixed all but one or two very minor issues. They will quickly clean the connections and be quids in
You can do this – easily!
No problem, good luck. If you need any new connectors or connector pins just let me know. They are easy to replace you just crimp the new on.
My GV125c 2011, I also have Virago 125 1998.
I love her size as I am 6’4″ and she goes well (just gets 70mph on original sprockets with no headwind).
Bought after being badly stored for 7 years with low mileage and failing chrome. But with bad chrome being replaced, frame touched up and a lot of polishing she is coming on great.
The new screen (eBay £30) is the latest addition and I have no more bugs on my visor.
Last of the bad chrome means I am still looking for front indicator bar and chewing over the handlebar change – something like Triumph T100 bars would do nicely.
The only real problem so far was split manifolds but that is leading to an adventure and were fixed with the right glue.
This is the old girl out at Peranporth airfield today.
Thought I would put this up too, a composite of all GV models.
I would like to get my hands an the new 125s engine as that is a complete redesign with different V angle to the twin cylinders. I also like the new air pod position, just a shame about the rest of the design. You can see the lines taken from the GV250DR (so very tasty) launched in 2017 which only lasted 2 years production. Hyosung seem to of slimmed the range to a single choice, a bike designed for all purposes. I will miss the GTs and cruisers.
Had a thought whilst out mowing lawn. If you find a burned harness conn or the new starter relay is no good message me. I will send FOC as have spare knocking around.
Also do not be tempted to scrape/sand any connectors/contacts. They will work first off but will corrode very fast to soon become unuseable. Isopropyl alcohol can be used instead of contact cleaner to clean contacts etc.
If it turns out to be a wiring harness connector in the starter circuit then it can also be cleaned with contact cleaner by unplugging conn, spray in conn and push fit and disconnect connector multiple times to clear dirt etc.
Just trace it all through with a multimeter and she will start on the button.
Hi Cpt
You are having a struggle, I am sorry for that. But you are so near to it all working, do not give up yet.
The starter circuit is very straight forward.
By shorting out at the starter relay you show most of it works, the engine is good to go etc. Easy to short rich or lean mix when you have her started. Much on here about mixture. My GV was messed with by over jetted and over rich both on mix screw and needle height by previous owner. You willl find that out when you start running it enough to colour the plugs.
The starter circuit has to have three things all work to fire the starter relay.
– First the starter fuse needs to be good.
– Second the ignition switch needs to be correctly passing power through it.
– Finally the handlebar starter switch needs to connecting when pressed.
The series of three can be checked easily with a multimeter.
Bet it is the fuse or starter switch.
Fuse easy replace – do not short out fuse replace it. Fuses blow as a protection so probably blown by old relay failure.
Starter switch issue, my old Yamaski had this issue and electrical contact cleaner spray sorted it. Just spray in switch on contacts and operate switch multiple times to clear carbon scoring/dirt off swith contacts (unscrew from handlebars and spray onto internal contacts).
Good luck.
Hi Marcel,
Yeh do not worry about the plug, old is still good.
The screw mount holes on the filter also needed to be altered both sides aswell. Since this bike is short term as I am taking DAS this summer. I will order your Ebay filter box with mashed screw, that has a red filter in so will fit perfectly. Bike has got to be A1 for when I sell hence all the new chrome purchases. Selling both 125s – the Virago aswell (after I fit the new rims).
Starting to look for new 250 project bike, I am going for a GV again as they are big enough to be comfortable with me being 6’4″. I intend to black out and restyle the 250 to single seat (not bobber more classic 50s) so the only provisos are that it will run and is fairly complete. I think I am developing a thing for Hyosungs.
On another note, I am going to attempt to replicate the manifolds in cast aluminim with a short silicone connector to carb. I have some long ago experience with lost foam casting and have dug out an old propane furnace and ordered green sand etc. The shorter front manifold will need a slight reshaping to allow the 45 degree twist n turn up to carb and give enough room for connector hose, but it should even the lengths of the manifolds a bit. I can 3D print them in casting wax or hand model them in foam and cast from there. If it works out I will send you up a set. It is such a shame Hyosung will not support their models with parts properly, it is the big failing with the company.
Have a good weekend.
Once again, thank you.
tom
I seem to be writing Simon is right today alot, fit the funnels in air box first.
Then slide box in from left watching not to catch cables with box mounting screw hole tab. Ensure the tab is clear of frame before lining up to carbs. Make sure all clamps to carb are loose enough and gently lean carbs to the left as you line up the funnels from the air box. Once the right hand side of funnels and carb are good then slowly straighten carbs, it should all go together as long as the funnel does not push into air box. It all feels like it is too tight to fit and leaning left with carbs allows airbox to wiggle backwards into position. It is possible and you do get the knack of it. I have had mine out 3 times now and can do it without cursing.
The new clamps make sure they are max 9mm width to fit properly. If you fit fit fatter ones they will seal but will pinch the rubber eventually causing damage.
Once fitted spray all funnel, manifold and vacuum connections with carb cleaner (flammable). If revs increase then you have a leak.
Marcel is also right, be careful with those intake manifolds they are £300 for a used pair. Mine had an old crackline split and I had to glue repair them, not ideal but it works. I use the same glue I used as an engineer to glue drive belts and o-rings with, so if the manifolds do crap out on you it is possible to solve.
Good luck.
I think Simon is on the money here. That top gasket on the exhaust, if that is leaking then you will have idle issues and top speed issues.
Hi
I do not have a 650 but went off and did some reading on it and this problem. It seems that the ECU was changed in 2009/10 and the 2010 can have the issue you describe. I have read of ECUs being returned and reprogrammed but with no help to the bikes stalling issue. People also seem to of replaced rectifiers etc to no effect. My gut would say a sensor failing making ECU compensate.
I noticed that you have no FI light come on.
A couple of people solved it by replacing the throttle sensor.
Hopefully Marcel sees this and has an answer for you, he really does seem to have a vast knowledge of Hyosung’s little hickups.
Here is a Netrider forum post that looks at your issue, same bike same year; https://netrider.net.au/threads/2010-hyosung-gt650-misfire-and-stalling-when-hot.111646/#p-body-main (I imagine that you have already read it).
Good luck and keep us informed. If I find any actual useful info I will post it.
Hi
If you want new https://hyosungsource.com/index.php?main_page=product_info&products_id=612
£58.32 plus £36.22 shipping from Korea. Takes about 2 weeks the stuff I bought sailed through customs no charges.
Otherwise measure center hole, the diameter of disc and the distance between centre of bolt holes like this sprocket diagram. As the disc is a flat one with no raised mounts etc then you should find an alternative easily enough. Just drop the rear wheel (if you cannot measure on bike) and use caliper/ruler/tape measure set to get sizing. Let us know what you find fits.
You can then match to other bikes. Can be a pain in the neck to troll through ebay etc and catalogues, they will sometimes have measurements listed. Often if you ring supplier they can match up sizing.
I am currently doing this for stem nut (standard honda fits) and fork caps (when I can get the stuck buggers off).
Good luck
Hi,
Check handle bar width before you buy a 650 master cylinder. As long as connections are all same it should work fine, but why risk it and change originality unless it is a known improvement?
You can buy gt125 secondhand on ebay.
They have new aftermarket and original at a good price on hyosungsource.com but he will not post cheap to Romania. Aftermarket is lei150.64 postage and lei134.33 purchase for https://hyosungsource.com/index.php?main_page=product_info&products_id=3663
Does Marcel have one knocking around? Message him and ask – it will be in good working order from Marcel.
Good luck. Let us know what you ended up doing.
Thank you for that info Marcel, it has shed light on that. I have no intention of altering mine but info is useful. I will keep my eyes peeled for an old 6 speed 125 as it has peeked my interest.
The fact that the 650 shares the same bottom end is interesting also, shows the strength of the 125 set up.
They are working for now. I am on the hunt for a set of originals but I do have a plan. Keep you all posted if it comes to anything (not what I mentioned to you Marcel 😀 ).
The manifolds are just a shaped tube with a standard manifold connections on each end and vacuum conns in the tube. There will be a way round this that does not involve paying £300 to a person for a used set. They should be £35 for one £70 for the pair. I take it as a challenge to find a way round this issue. Off out to take some measurements and order the parts I need. I am ok at fixing and fabricating repairs of many things as I was an electrical engineer who salvaged and repaired when younger – there is nearly always another way!
Hi Zigger Zag,
Rosie is beautiful, I have her rusty dirty twin.
Here is a link to “Whole lotta Rosie” live in 1978 for anyone who does not know the tune. AC/DC rocked.
Decided to get more chrome and paint shocks.
It is second hand, the only sore point is the nearest indicator.
Painted shock for now. Yes she needs a clean, that is this weekend. Good old smooth hammerite.
Have ordered new fork covers from South Korea. Just a front blinker bar to go and get the wheels and yoke polished.
But disaster has struck. I broke down will explain in another post.
