♠️ M77
Forum Replies Created
-
Posts
-
Coming from ebay , we have discussed there what we can do about the Air System and I advised which parts to get, so i will keep an eye on your ebay before i post anything
Welcome to the dark side! And good to have you over here, now i can speak unfiltered because ebay really does hate it when i try to divert people out of the site (they want to collect sales & tax the sellers there lol)
Anyway, it looks like from the tank it does appear it has a fresh looking TAP that says “ON/OFF” this is good, as we don’t want fuel to keep flooding the cylinders after the bike is OFF.
Let’s see what happens with her using that electric pump
I advise to replace ALL the pipes (Hyosung service manual says if the lines are 4yrs old from the factory, they MUST be replaced as it starts to break down internally and cleaning them delicate japanese carbs is not fun at times!) – Your grey lines are OEM , so well over 22 yrs old. Plus it might burst when the pump starts priming the fuel.
And while at it, replace the fuel filter too. See here:
Uprated & Braided Fuel Line + Filter Kit :: Hyosung GV125 & GV250 {Carby Models}
Keep in mind and make sure the fuel pump is connected to the correct plug.
There is a WHITE plug that has 1x Black line and 1x YELLOW line with a black tracer on it , usually near the upper part of your seat, this is for the fuel tank SENSOR
The pump (in my memory , if i can….) should be dark , like 1x black, 1x brown/red … but either way have a look.
2PIN PLUG that is “Blue x1 and Green x1” would be for the Neutral Sensor that’s going near the sprocket cover.
Another BIG 2Pin plug that is “Blue x1 and Green x1” is for the Stator —> It is in tandem with another giant plug that is “3x Yellow Wire” is for stator unit too.
That silver regulator on the bike was recalled by Hyosung (gets too faulty and blows a lot) , and it was superceeded by a Larger Black Regulator (but is still trash!) , usually regulators are Hyosung’s #1 problem to this day as they don’t make them but outsources it to woochang , Sun Electric, Hankuk in Korea.
See this one:
Upgrade Regulator Rectifier [Reg Rec] :: GV GT 125 250 R GTR Hyosung
You will get her running , keep us updated!
Just avoid the EFi black ones! , as they got updated & the respective bikes had updated forks to fit them.
TCTC Silver = Identical (Every Hyosung before EFi era)
So yes, you can get rear GT250 calipers , remove the bracket , and put them on your front mounts no problem.
Just bleed nipples may face down or up! (TCTC is funny like that!)
GV250 Front Caliper = Same as GT250R front , just swap the mounts as GV uses different forks that’s all. The actual caliper is the same.
KR Motors doesn’t sell calipers on their own, they “have” to come with mounts , probably why he said “i only have rears” . As Hyosung Korea pre-fits the mounts at the factory as they make them after TCTC sends the calipers to them.
We can’t buy new mounts separately that’s why , they come with the calipers as a whole set.
No problem, least you have a spare rear mount!
In my comments above ^ = Read it and let me know if the sprag clutch is working by testing with your hand and tell me what the BIG sprocket behind the flywheel is doing when you spin both ways
And which direction is it spinning (towards front or towards rear)
And which direction does it refuse to spin (towards front or towards rear)
Let’s just focus here first before i can address everything else.
The engine isn’t spinning properly that’s why.
Which Hyosung is this ? Becareful some sites are very sketchy with no real association with KR Motors Korea (Real Hyosung) but they buy their own stuff and store in a shipping container yard!
anyway, if its SILVER and says “TCTC” on it , it is the same caliper used on front & rear for the GT250R before 2012
After 2012 = All GT250/650R used an EFi rear caliper which will NOT fit the front!
If you get a rear silver caliper that looks like yours, remove the mount , and use the front mount. As the rear mount is for the rear only.
The caliper is used on the 650cc, that should tell you that it’s more than sufficient for a 250cc motor and you have 2 discs also which is a luxury as most 250cc bikes only have a single sided caliper and disc x1.
So improving it would require these:
- Braided Goodridge UK/Hel lines, you want a proper motorsport brake line.
- Stainless Pistons , because all hyosung calipers suffer from piston corrosion and seizures.
- Stainless Pins (that your brake pads slide one)
- SOme good grease behind each pad and on the PINS
There, you almost do not have to worry about that caliper for a very long time , anbd also all you are doing is cleaning the caliper during brake pad changes.
GV250 uses the same caliper , just remove the bracket and use your own bracket.
GT650 , they got upgraded to the BIG 4 piston calipers (kawasaki look alike type of calipers) , but the forks also got updated. They will not fit 250cc without the updated 650cc forks.
Other brands = Not known, I doubt it!
If fitting other brands / makes == Fabricate a metal plate mount to affix the caliper to your forks and possibly master cylinder upgrade to 5/8 (from St7, GV650, GT650 that fit 22mm bars as some cruisers have 1 inch bars!)
If your master cylinder says 5/8 = keep it. It’s as good as it gets and it’s very good.
You could still get 650cc calipers but must be identical yours (silver TCTC Korea brand), that’s pre-EFi (around 2005-2008)
Be a good idea to go stainless on your rear caliper on its pistons & pins as here in UK, we get rear brakes failing more than the front!
Just make sure you looik at your flywheel starting system cause if a part is damaged , it could flow loose inside motor and damage something else like a loose tooth! This will save you damaging another starter motor.
If we sort the crank first , then starter motor , and now we can move on to engine and electrics and fuel system using my comments from the 1st reply i gave you above ^
So follow it over & over again. If you finish my list correctly, you will learn something new to fix or make good progress.
You can go to halfords and get CR8E as that is the OEM plug for every Hyosung sold since 1999 , so always stick with CR8E no matter what.
Also, while there, ask then for a spark plug tool that fits CR8E plug , get more than 1 tool, incase Tool #1 is being awkward in the frame , get Tool #2 that may be shaped different to avoid hitting the frame or ancillaries attached near the engine.
Do that first…
Ride a little bit , come back.
Send us the picture of the FRONT and REAR plugs = We will know they if the HT caps are on the way out (common! hence we only use NGK Race ones that’s NOT plastic as i would NOT use plastic caps, they will crack!) .
Also have a multi meter ready , and we will send pictures on how to test your own coils to get some hard proof to see if the coils are OK based on readings.
You could do way better than your current mechanics at this rate , good luck!
Sounds like you need to drain the oil out entirely (grab fresh one and fresh oil filter)
Next , go to the stator cover , remove it carefully and SLOWLY (the flywheel has a strong magnet) , so it might try to pull the case back in and also there is a “STARTER Motor SPROCKET” idler gear (looks like this)
Then once the cover is off (don’t forget to carefully disconnect stator plugs near the rear shock / regulator area) , put it aside nicely.
Have a BRIGHT torch, check the “Flywheel SPROCKET” (like this one) , spin it ONE direction and check for broken teeth,
Spin the sprocket the OTHER WAY
===> If it moves ==> Sprocket SPRAG CLUTCH is damaged
===> If it DOES NOT MOVE ==> Then the sprag clutch should be one.It should only spin ONE-WAY (sprag clutch looks like this)
if sprag clutch is damaged , DO NOT buy 250cc version. (it will not fit!)You could probably repair your old sprag balls, with this one….
Here is a full diagram of your starting system behind the flywheel…
This is your starter motor below
It sounds like in the video the starter motor is struggling to spin the engine (with or without plugs)
Having a replacement starter motor is not a bad idea 👍
Old Starter motors that spin too slow make it hard to start!
A healthy fuel pump will always make a “whirring” sound as it stays continously on until you switch the bike off. Even as you turn the key on it makes that “whirr” sound.
That’s a lot!
– How about we do this to stop any hydrolocking issues as that would mean a big disaster later!
- Remove the fuel and vacuum line going to the “TAP” on the tank , GET A BUCKET! , if fuel pours out….even a drip drip
Replace the tap! - If not, but when you crank the bike, with throttle closed (don’t touch throttle), fuel is dripping a tiny bit in to fuel filter
Replace the tap - If you are sure the tap is OK, then remove the intake manifolds (the rubber pipes going to engine cylinders)
Replace the O-Rings you see there
(LIKE THIS ONE)
These orings can also a LOT of vacuum loss sometimes, and this is why you have a hard time starting and the taps & pump are not opening properly due to vacuum loss. - If the O-Rings are ok , replace them anyway , and you will be alright for a good long while and use STAINLESS bolts on the intake pipes because it is not fun drilling out stuck rusted cylinder bolts!
- Open the fuel pump (see if anything looks broken inside) (if it says MIKUNI on the back, then it is Genuine) = > If suspicious or unsure, just replace the pump with a NEW one (I would not trust used pumps)
- The bike will start to hate running on the tap, so that’s why Hyosung put a pump on it. It is advised to put it back or get a new one and refit the vacuum lines properly again.
If having a new pump ==> Crank bike for 5 seconds max => You should see fuel SHOOT out of the pump going to the carb … this means TAP & PUMP are OK now…
If its doing “little drop” (*very little drops*) , then go back to my comments above again ^ before reading below….
We need to make sure the fuel system is actually sending fuel properly first… - Open the “OIL FILLER” CAP next to your clutch cover ==> Sniff hard, if you smell FUEL inside ==> drain oil & replace filter!!!
Use motul 7100 oil
If you need a tutorial
Click here - If the oil is fresh and good, you saved a lot of money and possibly broken crank!
- Get fresh CR8E plugs again (yes again) , don’t bother with CR8E-IX (blue box) , they are rubbish on 125cc Hyosung — Keep it stock or use LASER NGK
If both plugs are sparking WHITE-BLUE , the coils are OK
If plug is sparking faint colour => Damaged coil or HT Cap (NGK HT cap is better)
If replacing one coil , replace both (keep the old one as spare!)
Your plugs will thank you! - If you crank the bike, and plugs are WET from fuel ==> Coils , Cap , Stator , CDI problems
(Sometimes = Clutch switch will stop sparks , replace it here — DONT BYPASS!)
(sometimes “Kickstand Switch” is an ass hole, and it must be cut off from bike, it is very annoying…. Make sure the kickstand plug is “bridged” (bypassed)
Don’t forget to check stand before riding!!!)If kickstand switch is bypassed already , maybe water has got inside that plug and turned to rust, check those wires …. if CDI thinks its “missing” , it will not spark or cut sparks after 1st gear == make sure the wires are good there and water proof it hard from rain and salty wet road!
I can’t stress this part. - If fuse box has rusty fuse, replace it. No questions asked, that’s an easy 2volt loss there! use blue 15A fuse only.
Try all this and let us know of improvements ?
Keep us posted, Simon knows his EFi babies inside and out lol, so follow what he says!
Topic locked as its a duplicate. Ill respond to your other one here
Then i would assume you have faulty coils ?
Swap the front and rear coils ?
If that’s true, it time to get a new coil and probably new spark plug caps (as yes the coils can kill them) – NGK ones are too recommended,
Since these bikes came out of the factory we always get orders for the rear coil and pair of plug caps. The rear coil fails first as they wasn’t put on properly and the ECU can’t always tell you its a coil problem.
Sometimes you may need to also make sure the regulator is doing “14.2-14.5v” MAX & LOWEST , if it falls outside 14v in any revs , you will face more electric issues and possibly a slowly dying ECU as it’s the most voltage sensitive of all.
Do this with a fresh set of CR8E plugs (yellow box) = DO NOT use “CR8E-IX” (Blue Box) as Hyo 125’s don’t like em. Surprisingly yes the Stock plug or LASER NGK plug is way better for the injection 125cc. Carb Models are hit and miss most of the time.
If it has CR9/CR7 etc = bin them straight. CR8E only.
Keep us posted , we will get to the bottom of it 😉
Just hard for me to give a straight answer online without the bike next to me unless its a common issue we’re already familiar with , unless otherwise in the end, all the checking you did , probably will turn out to be a bike just needing a new part or you missed a small simple thing such as corroded plugs (strip it all down and clean every plug you can find) , unlike Carb Models, the EFI system also checks “resistance” to certain sensors. So if the resistance is too low or too high , it is usually caused by an oxidized / rusted plug that needs cleaning out instead of the actual sensor being fault.
Ie. Tank Level Sensor plug says “100 ohms” , it has a yellow wire (the black one is for ground usually) , if i see the same yellow wire at the dashboard connector , it says 150ohms , i think i have an issue along the wires that rose the resistance quite significantly possibly a bad kink or exposed wire rusting or connector at the dash has water invasion (if its not waterproofed) etc…. Assume that an object attached to the engine has high resistance but the ECU is expecting it to be low when it calls it , it will go haywire sometimes when running , as it’s not getting the values it wants. Hence Simon and Myself in this site usually repeat to owners to try to ensure the harness is as pristine as possible before replacing faulty sensors on EFi bikes. Resistance that is too high on Stators will burn regulators , slowly cook everything that’s connected to the harness unless the fuse blows first, the ECU won’t behave the same anymore, but since you have a DELPHi unit (hopefully, not the 2018 MOTO1 ECU) it “may” or “may not” warn you with an error code at the start “Battery Voltage too high” etc…
I digressed a little!
Hey
Check this topic, just incase it is the idle speed controller having a loose/damage o-ring like this guy found out below:Also try the cleaner mentioned in the topic above to clean out the fuel system
Keep us postedTry the Vulcan 800 ones, the worst case is just a bit of metal work to shave some off the metal to slot in to the bike rearset?
In honesty, the Daewoo ECU is problematic , thats why not community investment was made to attempt to mess with it on a large scale , and the only tool that can reliably Read the ECU is “Hyosung Scan Tool”, you could ask local dealer in your country to buy one as Hyosung sells it to Hyosung dealers only. I believe Delphi is a better system overall. As you said, Daewoo is rare , so it is best to leave it alone and improve other parts like using NGK leads for the coils etc and using MOSFET regulators.
Unrelated My front left-foot peg broke and I need a replacement. I see a tonne of “Universal” footpegs on eBay. Could you point me in the right direction? I don’t care about keeping it OEM, so long as it is decent quality at a decent price
im not sure 100% but look at “Vulcan 800” foot pegs, they may “just about” fit but again this is the closest bike i can think of
or try Vulcan 800 footboards (footboards are way more comfy than pegs i wont lie lol)
