♠️ M77
Forum Replies Created
-
Posts
-
It is a GT125 Carb Model? what year ? and does it look like this ?
I have 2x used ones in stock, this is the 1st one i have:
https://www.ebay.co.uk/itm/257122314120
and this:
https://www.ebay.co.uk/itm/257288241573
ebay should allow Global Shipping already in the checkout , if it fails, send me an email ON HERE (not ebay messages) and i will make a quote , as ebay wont like sellers making transactions inside ebay messages.
If not, we will wait for the picture – It sounds like an LCD display failure?
Great ride , that smile says everything.
I envy your sunshine and sea front views , while we are in the snow unable to ride just yet , you will be okay over there with that GV250, it will keep going 🙂
What is actually wrong with it ?
And post a picture on your next reply please if you can.
I think I have the only GV250 in Hawaii haha.
Find hawaiians on social media and see if there is a biker community there and ask around, you will be surprised there could be one more. I am suspicious we have a member on here with a GD250 EXIV model but i could be wrong, if its true it could mean they have not posted in the forum for a long while.
In regards to your starter issue.
Replace the starter motor first, and crank on full throttle with a new relay. Test and report back ?
You can also carefully , extract the flywheel out of the bike and look at it , if it is under 10,000 miles old, I don’t expect issues with the flywheel system yet i hope not.
If in doubt, upload here what you see.
If you drain oil, replace it with Motul 7100 (very very good oil!) and get a fresh oil filter. Better to replace oil OFTEN as you like to keep the engine healthy as possible.
I change oil every 1,000 miles on my bikes. It is OCD / Crazy but i’d rather waste the oil than scream at engine replacements lol. The local recycle plant should take your old oils and they will re-use it for something else so you’re not killing the enviroment.
Welcome and upload a picture of your ride!
It could be a curse for you but it should not be, be the one that has a bike that isn’t common , gets more attention heads turning.
Having a Hyosung will make you a good mechanic eventually 😉
Take good care of it!
Hey bro my gd250r engine cuts off after about 30min of riding when I let off the throttle
Already responded to your own thread.
It may be that you will need to check the injector and lambda sensor, get to the ECU to get error codes if possible.
If not, check the fuel pump too.
Then also check the TPS unit , if it shuts off and won’t idle back.
You didn’t tell us if the bike starts right away after dying , if there is a flashing red light etc….. So do the above ^ and report back your findings.
Good luck!
Get a venier caliper that has long arms and measure the external size where you want to cut it (it could slop down from 56 to 50 the further down you go.)
Depending where the pipe is cut, the exhaust may even downsize to less than 51mm if its cut down too far.
So at the 3 bold flange , go inside the exhaust hole, get a vernier caliper and measure the hole size , if its something like 47mm,. then the exterior would be about 49mm (depends how thick the wall is. Measuring the diameter outside is better if you can.
You are right to ask, some 650 owners chop their pipes and put some kind of adapters (makeshift) or even make entirely custom pipe setup if the old system is corroded,
Measuring is the best way to be accurate (and i will assume you still use OEM pipes)
Take your time, no rush as we don’t ride much in this ice this week ourselves in the UK
Do you have any pod filters on the bike ? and would you say you are using stock CR8E plugs ?
If possible, try and see if you can gather fresh set of CR8E plugs from halfords if they are open now , and go for a short ride when it is safe (ice is on the way!)
Come back, take pictures of the plugs, and show us. This way i can try make a judgement based on how the threads look and how it also looks inside.
So get side view and inside view of the plugs.
Do a compression test again after its hot.
Spray carb cleaner on the rubber intake pipes = did revs change ?
Spray carb cleaner on the airbox rubber openings that swallow the carb (especially the front carb doesn’t always get fully swallowed by the airbox_
Jetting is fine as long as it is 90F / 92.5R and 15 Pilots (both cylinders)
Mixture Screws = Be very careful here as it is easy to round them off. — If you see a _____ dash___ make a mark on the carb, then count down the FULL turns clockwise until it stops , then go back to where it was. Eg. I screwed down the front cylinder, and it was 1 full circle and then half a circle , this means 1.5 full turns downwards or 1.5 full turns from stop to counterclockwise. Least we know what mixture it is.
Mid Range RPM = Have a look at this topic to see if it will help ?
[Tutorial] How to adjust Carb Slide Needle (Tuning) – Hyosung GV & GT 125/250
High RPM = Does it do high RPM at any gear at all (peak power is at 9-10k rpm, so you definitely don’t want to redline those pistons anyway) No more power after 11k rpm as valves start floating and premature wear happens faster. Staying under 10k is good and it will thank you.
Coils = Please report the OHMS readings for the coils (without HT cap attached)
CAPS = are they stock caps ? (problematic!) = 99% of us switch to NGK caps where possibl,e (DO NOT USE PLASTIC NGK caps , they will crack too!) , we use rubber versions, like you see on the site. If not , for a cheap fix, get another good set of stock HT CAPS on ebay from a local UK seller.
HT CAPS OEM = 7-10K OHMS on their own is good. (10 thousand yes max)
Coils = Sorry here is the link to test before i digress!
Rectifier – How to Test Stator , Battery , Regulator – GT125R Carby
Test your stator = Trust me if the pulser/sensor acts funny, so does the CDI and coils, ignition/sparks/timing starts with the magneto/stator.
You got this and happy holidays!
The GP Sensor would need replacing yes , and also you can find some on eBay UK and eBay USA as these are still good 250cc markets , however be cautious using hyo sites that are blue and white , some riders on this forum have complained a lot resorting to asking PayPal to sort it out for them , unless they have genuine stock issues then they should give you an update.
A GP switch acting fishy does trigger the FI light as the ECU is expecting it and it assess (or guess as best as it can) to ascertain if you are in Neutral or Some other gear before starting, hence EFi versions have 5 contacts on the switch itself , carb models are not suitable as they are hit & miss with some 250 ECU’s – The carb versions have 1 contact point that says “Neutral On” or not , the CDI doen’t doesn’t typically care to sense if you are in Gear 5 or 1 , the EFi ones would , it helps with timings on the rest of the electronics.
Don’t throw it away, it will be a handy backup. Sometimes it does come back to life briefly – Get yourself some “stainless steel” bolts and a fresh O-ring if possible, that gearbox drum behind the sensor chucks a lot of oil!
1st pic is hard to tell but , focus on the ECU and relays first , then go down to the front, less headaches that way actually. Better to work from the back as connectors will be more self explanatory (rear eg = relays , lights , thats it. there is a 2 pin socket next to relay, leave it. and another 4pin socket hiding itself inside a black jacket, ignore)
If not, more pictures will explain it better.2nd image = there is a little white plug with 1 brown and 1 green wire = Engine temp sensor ,
ET sensor sits at the front cylinder head under the throttle body.
Take your time. Also this may help (it is for a 650 but use it as a guide to follow where most parts connect to) (especially where it says “DASH CONNECTIONS”) https://hyoriders.club/forums/topic/wiring-tables/
You noted speedo problems. The link above ^ may verify your harness connectors towards the dash itself.
Then follow the wire colours down your harness, if a dash says “Blue/RED & GREEN” this is 2 wires in a 2-pin plug, it will say fuel gauge, find it on the harness and collect the fuel gauge sensor on the tank
Blue wire from the dash on its own (example) , might say “Neutral” , find it on the harness near the middle so it can reach the N Sensor on the engine, the N Sensor will have 2 wires , the extra wire is for the ECU + Signal to trigger the starting processing (not all 250’s have the same harness or ECU, hence again i can’t always give an easy answer but generally in my experience touching every ECU i got my hands on, DAEWOO is more fussy, very fussy! – excercise patience if you can and do 1 small thing at a 1 as it helps you study too )
I am sure this forum and manualsLIB already have 250 manuals with wiring diagrams at their last pages of the PDF documents. Or even look at the 2008-2009 650GT (It uses a daewoo ECU , only a few of of its parts will work on 250 , so it gets easier to follow. Ie. 650 EFi and 250 EFi early model use the same neutral switch , same clutch switch, the manuals will tell what colour wires they are. Other things like Fan Control, Thermo Switch, etc don’t apply to 250cc as it doesn’t use water cooling.
Hope this helps and good luck!
Have you checked if all the connectors on the bike have water ingress lately?
Also , i could remove the stand switch, inspect the mechanism -> then use contact cleaner to clean the plugs. If the ECU can’t sense it , it won’t start.
Clutch Switch = Same here.
Neutral Switch (under the front sprocket) (don’t pull it out as there is a small spring inside connecting the drum, which is used to track positions , so be wise) and have a bucket as oil will pour our. Top up engine with fresh oil to avoid starving the gearbox. (if 100ml is drained there, then top up 100ml back in)
Ground connections = Black wires or any wires attached to the frame or battery negative.
Starter Switch = Check its PLUG under the fuel tank and open the Starter Switch just to make sure the kill switch contacts are OK. use contact cleaner (loads at halfords)
Starter RELAY Solenoid (Depending on your year GV125-S , it may have “Solenoid Starter + Its own fuse” or just “solenoid” by itself. ) = If these go out, your start button doesn’t work.
Doo a deep dive in your area to find any wrecked 250 EFi, they would be great for parts. Daewoo uses an OEM black pump that has a different pressure rating (harder to find) , Delphi pumps are OEM Blue and have OEM numbers printed on them. airbox EFi has port to slot in the ISC valve (idle speed controller) , and it sends 2 air pipes down to the throttle bodies. The pump splits 1 fuel pipe in to a T-Piece which joins 2 smaller pipes feeding either injector (front + rear )
Okay, but what about the return line? I cant figure it out. Thanks a lot!
have to see what your setup looks like, not all needed and it’s complicated to give a straight answer due to differences between the older and newer pumps and wether the past owners have made modifications to the fuel railing systems such as using a Kemso aftermarket pump or changes to the pressure relief valves on the pumps.
The older black pumps had different pressure ratings and had 1 pipe ==2 pipes ==then single pipe down to the frame == then 2 final pipes to either throttle body where the injector is.
Most of the time , you will see a single hose leaving the pump going to the middle section of the bike frame. It breaks off in to Front Pipe and Rear Pipe after that junction. The 250 is a little less complicated than the 650 thankfully.
You will deal with more air pipes for the throttle bodies , air lines from airbox to Electric Valve Pump which sends even more air down the exhaust pipes (emissions control) (Some bikes out of UK actually have far more , like the american versions for some kind of extra emissions control) , more pipes from either engine cylinder going in to the airbox etc.
Doo a deep dive in your area to find any wrecked 250 EFi, they would be great for parts. Daewoo uses an OEM black pump that has a different pressure rating (harder to find) , Delphi pumps are OEM Blue and have OEM numbers printed on them.
airbox EFi has port to slot in the ISC valve (idle speed controller) , and it sends 2 air pipes down to the throttle bodies.
The pump splits 1 fuel pipe in to a T-Piece which joins 2 smaller pipes feeding either injector (front + rear )
I would stay on the carb system as the FI system on the 25o means you have a lot of EFi parts to stay on top of. Carby is better as its less maintenance and less worry, it’s just better. However, in regards to your cluster , post a picture so we see what it looks like first.
If still wanting to go EFi , check the wiring tables posted by another member in this forum , including this too https://hyoriders.club/fuel_induction_manual/
Also wiring diagrams vary wildly so choose the appropriate manual (on this forum) or ManualsLIB site , Hyosung used 4 different harness on EFI models and 4 different ECU, they use different sensors , it is a big thing to match everything right or you get problems trying to run things properly. Common now is DELPHI ECU (it will say it on the ECU) and uses Delphi Harness (2013-2015) and Delphi V2 harness (different connectors and more fuses) (2016-2019)
Older ECU is not possible anymore (Sentec, Daewoo, etc due those companies not existing anymore) – Hyosung is using Delphi Electronics going forward , you need a tank that accepts EFi pumps too, and possible EFi throttle bodies and a wide array of sensors, EFi air box, injectors , Exhaust should have 2 ports for lambda (Delphi later models) or 1 lambda port for older Delphi or older ECUs .
Though It is hard to comment further until you provide pictures and details of what you have laying on the floor , and possible tell you what system you have.
If the harness has been chopped up , it can be saved but be suspicious! There is a reason carby was better outcome for the bike probably and Regulators are common fault for ALL OEM Hyosung and Chinese Junk ones. Use a TrueMOSFET one such as SHINGDEN Japan , if not , just visit ElectroSport USA , they make an “OK-ish” regulator for the bike.
you will need an OEM GT650R master cylinder (actual one) & clutch perch mount to consider using their thicker adjustable shorty levers you see online. The OEM 125cc master cylinder will not fit 650 levers.
Others resorted to “universal” aliexpress master cylinder and clutch kits but you will be back needing a new clutch cable, Hyosung’s OEM perch stays undefeated , plus i can’t trust £10 master cylinders in emergency braking. So I avoid them.
If not, get OEM Kawasaki ZX9 Front master cylinder and use its shorty brake lever. As for the clutch side, you will study how to implement a hydraulic clutch (custom work & time consuming for a novice to fine tune it) , i’d recommend staying with traditional Hyosung cable setup. Hydro is overkill for 125cc & more maintenance jobs to keep on to off.
Well done! – Looks like the big panic was over! – Be good to definitely spruce up the clutch and yes proper oil too (Motul 300V or Motul 7100!) – Change oil filter again! Gearboxes LOVE clean oil and you will notice a smoother shift initially.
Gear Sensor = Under the front sprocket, be very very careful as oil will come out of there and it is secure by an O-RING , there is also a spring inside too! So you don’t want the spring to fly out.
Get contact cleaner == clean the Socket going to the harness , incase it got oxidized and some signal loss could happen if there was water invasion.
Use Compressed AIR to blow it clean after using Contact Cleaner (NO WD40 please!🔥)
Get also ACF50 (Halfords) – Spray a tiny amount inside the plug , a very tiny amount. this is every biker’s best friend when it comes to anti rust measures and it is electric safe too.
Good luck!
If the bike is older than 4,000 miles old, you could take a look at the clutch basket.
If you squeeze the lever in while idling , if it gets quieter = time for a clutch overhaul , sometimes could add to the gear slipping ?
Drain the oil and use Motul 7100 forever (it is possible the dealer used rubbish trade oil from a barrel in workshop, they don’t really play nice for gearboxes long term) – It just an idea.
Then go for a gentle ride , be slower , and see if gears shift through nicely.
Believe it or not, too much chain slack can mess up smooth gear changes and also remove the sprocket cover , see if the sprocket NUT (front engine) is loose or the washer is loose at all ?
If we can do these things first, come back and let us know if it helps.
Idling issue = Go to halfords and get “WYNNS XTREME FORMULA GOLD PETROL” (ignore redex, and ignore everyone else! They are trash)
Put half a tank of fuel inside and put 1/2 bottle of that formula inside that tank ===> Ride until it is 1 bar of fuel left. See if the idling improves (We are “soft cleaning” everything to do with fuel parts , so WYNNS will run through pump, injectors, fuel lines, then gets burnt away inside pistons and O2 sensors pick up last = This should possibly see if fuel clogging was an issue or not.
Idling at 1600-1800 all day is normal and it cannot be adjusted by you. It is ECU control to keep the engine idling
It would be a good idea to get fresh CR8E plugs and stay with them or get LASER ones (good plugs) = DO NOT use “Iridium IX” plugs as Hyosungs hate them.
IX = Blue Box (Avoid)
LASER = Rainbow box (CR8E LASER)
CR8E = Stock plug (yellow box)Now as you finish riding until 1 bar of fuel left ===> Remove the plugs and show us the pictures here, so we can see if the threads have changed colour and how much. Also pictures of the “inside of the plugs” so we can see a trail of what’s going on (too much air, too much fuel, poor sparking (ie. failing coils or NGK caps which the ECU cannot sense) = The ECU will not tell if the coils are failing or the plug caps have issues , you will find out the hard way when the engine stops altogether or starts firing irregular or shaking (power loss when riding too as running on 1 cylinder etc)
Take your time, I said a lot, but i expect some kind of indepth report back from you so we know every step you took and if it is doing better or not.
If it is something stupid like a loose plug or dodgy clutch bearing or 1 snapped clutch plate (happens but rare) , you will tell us and likely someone else will read this thread to avoid ££££££s of labour at garages who don’t understand Hyosungs at all.
