♠️ M77
Forum Replies Created
-
Posts
-
Fair enough, take all the tape off , investigate the loom 1 strand at a time using your meter to test for any breaks.
Then re-wrap it all again nicely with fresh harness-tape (electrical tape that is proper so you can keep some water or winter misty air out with can cause wires to go brown inside)
If the N-Sensor is faulty, we can send you another one for you to try but i would also get a new oring from the shop for it as there is a camshaft directly behind it with oil, so you don’t want any leaks.
Also, relays = Are the indies OEM or aftermarket ? = If OEM , try to replace both the bulbs (shop) and the actual OEM relay unit (will try find it in workshop)
Defo sounds like something happend with the charging system (reg & stator) that cause electrics to go haywire now., well before you had a chance to upgrade the regs & coils.
Don’t forget even when the bike is OFF (keys out) , the reg is always connected permantently as the red wire goes 3 ways (fuse, battery , loom unit) = if the relay is buzzing without indies being on, that’s gonna cause new battery changes eventually and a very annoyed charging system
Here’s a question for you. The loom has diodes in to stop back feeding of voltage. Could one of these have gone bad and there is voltage back feeding somewhere through the system when I turn my lights on causing the tacho Junp and potentially my issues of frying coils and reg/recs?
Some diodes are simply called “mystery diodes” which Korea doesn’t tell us their actual purpose until we strip the whole loom apart before re-wrapping with fresh black leccy tape. Also Near the “Rear Coil” , there is a relay unit that controls the Neutral sensor , if the green light comes on on dash, the sensor should be working , i believe a voltage overspike (beyond 15v) or too much “amps/current” (stator wanning) would fry it slowly overtime.
Some relays in the harness control lights or the horn beeper. Some older hyosung looms (even 650s) had some at the front that look like relays but actually were called “igniters” for the spark system (like this one…here)
Hints from experience =
If the “RPM gauge” is zig zagging at any point = Coils , Stator , Harness , Battery (Zig Zags can happen when lights turn on, as lights mean extra load is being requested by the bike to stator/reg/ battery to power the lights on top of running the engine)
If the “LCD GLASS” that says the speed you’re doing goes dark, dim, flickers = harness / dodgy part on bike that’s taxing battery / battery or reg itself.
If the “rpm needle” is zig zagging while idling (with lights off) = see above ^
If the “rpm needle” is sweeping slowly up and down = Hunting for fuel , carb , pump , tap, or coils = Plugs may be shot at this point.Maybe i am crazy ? I wonder if i can do double-reg mod ? hhm…… yeah… too crazy but … i might try that for giggles.
Flatter start but gets better as revs rise = That’s the OEM reg that’s already inconsistent. Top end getting better means the reg was doing 15V (I hope not, but not a deal breaker , as that’s the OEM limit) = Though, it could also mean, higher revs forced the bike to get more juice from batter than the OEM reg can keep up?
The upgrade ones should be straight 13.5V from the get go, hence the electronics on your bike have woken up sooner but it won’t try to go beyond 15V. I think i have sold so many worldwide, not just here in UK , the regs i get come from Poland , the distrubitor has been good to me for that and some regs I get are from YSMoto (UK) (YellowSquare Bikes UK) , so they have been good. I’d be annoyed if every reg went on fire!😢 – You might have a voltage leak as you say or something is being taxed elsewhere. Wish i had the motorbike with me in workshop to do more indepth analysis
As for jerking = Our final request is to show us the plugs (Then i will know its fueling or coil issues or stator issue as it does control sparking with the CDI as revs go up and down).
Lights draw 55w , so a weaker reg will dim things a little bit until it catches on. It may look like you will need a 650 reg kit we do, this should be your LAST ever reg. I would be amazed if the 125cc blows it as it is about 3x bigger than the OEM , it’s very big. My 650 customers are happy with it, especially with EFi 2012 ones. We can’t be sending you new regs all the time lol. Spring is here, keep her , bike season is officially here and you know she is a good ride when everything is taken care of.
I’ve just fitted a brand new CDI and nothing still the same
no sparks on either coil #?~ or just 1 coil with the new cdi ? which coil sparks on the new CDI ?
Also can you show us where you got the new CDI from ?
I can see the flywheel is a modified MS3 scooter rotor and modified MS3 stator you have (18-pole type for 125cc) = Those new ones don’t exist anymore but we still custom ones instead. It’s getting harder to get 2002 flywheels , so make the order happen when you can as one day i will mark that catalogue as “Sold out” (can’t get anymore all over earth lol) , the sellers i work with have shot up their prices for me to buy their 2002 rotors that work with my stator kits. Frustrating sometimes when i need to keep costs down for everyone in UK
Hi sorry for the late reply I’ve just seen your post The bike is a 2010 with green led and yes a black rev The wire is connected to both earth’s on the coils ,someone said and I cannot remember where that he has it on his gt250 but has no idea what it does,
if you get free time too take her apart very slowly , find out along the harness where the plug is supposed to go , i am sure “very few” hyo looms did have something like that to be fair, it might be called “igniter” by hyosung or used as some mystery relay for the horn , but check the harness , peel the tape and re-wrap it with quality black electrical harness tape again.
Do you have the following ….?
- Accessories on the bike that need electrics ?
- What exact battery is on it ? (name and size of it) and how old is it ?
- Has the battery ever had an independent test for free on any local garage or halfords (they use special Yuasa meters for that)
- When riding , does it misfire or jerk forward and back sometimes ? (ignition coils vs cdi = as they do mess with electrics if they go haywire and your reg is still forced to keep sending “regulated” 14 volts on top of charging the battery too)
- How old are the headlights ? Exact bulb and name ? (Generally very old bulbs get more yellow ish and can tax the wires and charging system to light them up) ( I mean new ones already want 55 watts out of the electric system )
Depending on your replies (all i asked) , we will see if it was best you got an even bigger reg rec that’s used on the 650 bikes (see shop) but …… rarely …. As the general global consensus everywhere is that OEM Regs die often more than the proper aftermarket ones (Hyo is power hungry especially later models with more electronics) , hence hyosung changed stators many times across 125 to 650cc models , even the 125cc has had 3 regulator changes by Korea themselves. A good aftermarket reg keeps it going as long as the stator behaves well , and “chinesium” regulators will go on fire faster than Korea’s own regs.
Something on the bike is “overloaded” …. The reg looks like it was having a hard time OR also check the stator OHMS after its warmed up for 10mins , and tell us the resistance (more resistance = more tax on the bike , bikes don’t like being taxed too much) (any bike in general) thats why the stator ohm readings are usually checked ice cold because we know it rises up with heat (heat is the enemy of any electric device on earth)
Yeah also take a picture of the flywheel if you can please ? Hyosung did change flywheels in later 125 engines.
It means you will need a new nut and a new washer (look at our shop bove ^)
And look at customer pictures, the nut needs to be 60 ft lbs torque tight ==> then fold the lock washer 2x to stop the nut getting loose ,
The nut fell out because nothing was holding it anymore (the washer failed its job or it was not tight or folded properly)
Also put fresh oil again (see tutorial below) and check the engine runs again before riding it. Check for leaks again.
If it is leaking again, when it is idling, = take a picture and show us.
[Tutorial] How to Change Oil & Filter on Hyosung GV + GT125/250 +R
It goes to the bottom of the bike , and yes it just drains fuel before we remove carbs away from the motorcycle 🙂
Do not throw away old carbs, keep them for spares, they are very difficult to get nowadays
Or send it to us , we might play with it if it is too damaged for road use!
Hi I’ve tested the 2 wire plug (green & blue ) 81.4 ohms on 200 and I’ve test the 3 yellow wires coming out of the stator 01.7 ,01.5 , 01.4 ohms on 200 . I hope I’ve got it right this time lol . Thanks for all your help Marcel
Yup time to change the stator, it’s out of spec especially the yellow wires. And it is a “MUST” to get a new regulator with a new stator too. It’s too important.
Drain the oil and look at the stator unit , take a picture and show us please (I have known ex-owners to try switch things up) not all 125 stators are the same (Thats why our shop has 2 separate 15 stator listings)
Also it is “possible” you may need a new CDI ? Take a picture of it and show us ? (Just to make sure past owner didn’t try to use a GV CDi than a GT one)
This is assuming all the coil wires at the coils are not broken and the same colours are the same on the cdi plgus = then i can’t see anything else breaking sparks apart from the stator unit
I can’t see the “Clutch Lever” switch being faulty as it would stop the rear coil sparking too. Don’t bypass it.
If you are suspicious of it , buy a new one from our store.Side Stand Switch = Bypass it and as Simon on this site would say “put a paper clip across the plug” to bridge it and tape it hard as rust in the wires will cut sparks off 100000%
Regards
We will see if stator is a problem but try to test what i said in the previous replies and spark plug pictures
I’ve said it before, and I’ll say it again, this motor is a real treat! Putter around it’s happy. Use the midrange grunt it’s happy. Rip it to red line and it’s happy. My well baffled carbon can sounds very right. The Dunlop Mutants are amazing, wet, dry, icy frost. I haven’t used Dunlops since 1982. Call me impressed!
A happy hyo owners is the one that will make sure she is treated on dates and gets all the maintenance goodies under hood to keep her going. I am happy to hear that.
I might consider the Dunlops next time but it’s hard for me to move away from Michelins at the moment as i’ve been let down by various tyre brands (UK is wet 3/4 of the year lol)
I believe the stator is gone , can you confirm again = Switch your meter to under 200 ohms (hundreds, not thousands/K’s) , then tell us the figure again ?
Yes the tacho reads cylinder one , cylinder one gets the signal from the CDI , the CDI, translates both coils to the correct spark responses based on the feedback given by the stator unit.
Okay,
Try this… Take out the spark plugs and show me ? Are you also using standard CR8E ? (I hope so)
Next , remove dashboard ==> Remove fairings ==> Remove tank ==> Follow the “BLACK & YELLOW” wire from dash board to front coil = check for any ohms
It should go from 0 omhs to infinity 9999999999 ohms = If it stays zero, harness is broken somewhere and dash board is not able to read signal from front coil.
Also check black yellow wire from front coil to rear CDI unit = check for circuit is complete with your meter ?
When your bike is running =-==> Check under bike for “sparks” escaping the ht wires on the coil (coil damage)
Soon = we may need to replace your stator and regulator again , but i cannot remember if i send you Stator & Regulator for you 125cc a long time ago and you need new parts for a 250cc now ?
- Got the bolts of and the big screw but just need to get a puller now , is there a specific size puller or they all a generic size , cheers
I forgot off my head, but is it possible you can measure the bolt size that you took out from the center and find the thread pitch ? – If not i will try to dig through my archives the exact puller tools Hyosung uses themselves.
You can also get a “generic” big rotor holder for bikes like harley or whatever that allows you to lock the flywheel in place (You will need it to tighten the bolt back in after swapping the starting clutch)
Looking good, will use one of the pictures as a background for the site banners soon 🙂
I do think Hyos are meant to be going out in the countrysides than whizzing around the buzy slow metropolis!
If the revs did not change. That is good.
Make sure the airbox is not leaking on top of the carbs.
Look for a 2nd hand sensor in your country and replace it ?
or take it to a garage , ask them to clean the 02 sensor for you and try again.
Make sure to reset ECU (unplug battery for 24hrs)
Hi I’ve tested the white and blue wire and the front coil black and yellow wire and these ok no wires broken . I have tested the two pin wire coming out of the stator and it shows 2 homs, I’ve also tested the stator the voltage regulator or (R&R) and the battery and both coil packs and all seem good And I do have a power jump box just in case I need a bit more kick , All I have to do now is test the harness, If that is ok then i’m stumped 🤔
What “Ohms” was the stator 2-pin plug ?
Don’t jump start on a live running car or truck = that’s how it fries everything.
You can take the battery out of the car and test with your bike inthis case or make sure the car/truck is fully off and runs 12V! (some vehicles are 24v!)
Good luck!
