Desperate for help

[sirus2014]

I have a 125 4 stroke bike that has stopped working and desperate to get it working again as with out it i can not work. If i could afford to take it to a garage i would but i cnt.

The bike was running fine untill 2 days ago when she decided to just die on me. Before it died she did start to bog out, it was fine for a few mins then just died stopped dead on a roundabout. I tried to start it and engine would turn over but not start (actually started for a few seconds then stopped dead again) So i tried to bump start it, i put it in second gear held clutch in and ran like the wind and let go of the clutch you could hear it trying to start then the back wheel locked up. Tried again with the electric start and still could hear the engine trying to start but nothing. I changed the spark plugs and checked plugs was sparking, i cleaned the carb and jets out and also change the fuel filter and still nothing. Anyone with any ideas please please help
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Knowledge is everything.

[........................]

What bike is it?

Basics first, it's got fuel? When did you last check the oil level? How much oil has it got in it now?

[sirus2014]

hyosung GT125R

[Vincent]

Were the plugs wet when you took them out? If you can't remember, try kicking it over a few times with full throttle and see if fuel is getting through by checking the plug.
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Space Is Deep

[Commuter_Tim]

[sirus2014]

Hi sorry

Yes has fuel and oli was checked that day as i always do checks prior to riding. I did not check if the plugs was wet but will def check that 2mo. If they are i guess that will let me know there is fuel getting to it? if not where would my next point to check be? as i have checked and cleaned the carb out.

One thing i did not mention was i did have a bout a coke bottles cap worth of water go in my tank the other day, the tank was full so didnt think to much of it. also the wind blew it of the stand the day prior to this being a heavy bike it hit the floor hard.

[Rogerborg]

Definitely sounds like fuelling.

Can you see fuel moving through the fuel line?

When you say you cleaned the jets, how did you clean out the idle jets? I'm not sure what you'll have in those carbs, they could be screw in jets, or just pressed in, with tiny holes that are a prime candidate for clogging up.

When you had the carbs apart, did you check the float heights? If not, have you tried giving the bowls a whack? Sometimes it really is that simple.
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Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike

[Paddy Blake]

It sounds to me that you got more water in the tank that you thought.

Leave the fuel in the tank settle over night or hours and then drain 2 cupfuls into a glass to inspect later to see if there is water in the bottom of the glass.
Drain the float bowl then try start it.

If it has a vacuum hose going to the fuel tap you could suck on that to fill the float bowl.Leave the float drain screw open at first until fuel comes out so you know the floats are not stuck and the tap is working.

[Vincent]

[........................]

There'll be a drain screw somewhere, undo that and drain some fuel out. If that doesn't work take the float bowl off have have a look at the float assembly. While you're there change the float bowl screws to small cap head bolts.

[Paddy Blake]

[kramdra]

Sounds like water and rust. Drain tank into a clear bottle and see if it seperates https://i1133.photobucket.com/albums/m593/Kramdra/IMG_20130111_181140_zps97021596.jpg

A fuel filter will not stop rust or water, but I still a good idea for larger dirt. Even a 25 micron filter lets a lot of rust particles through (which will settle out inside carb)

Its almost impossible to fully drain a tank by gravity alone - so ebay a suitable sucking tool (ebay 6 quid oil suction gun/syringe. Aviod medical syringes, they dont work with fuel).

Buy yourself a £6.49 mini moto/pitbike fuel tank from ebay. Bloody useful for testing/playing with carbs. Its tiny, holds about 1.5litres. Also recommend quick release fuel fittings if taking tank off often, but they cost £9.

[Taught2BCauti...]

Going right back to basics, for an engine to work, you need:

1. A Fuel/Air mix - with the right amount of fuel.
2. Good compression.
3. A spark at exactly the right time.

If you are getting a good spark when you remove the plug and hold the body against the engine casing, make sure you aren't getting an arc to earth from the HT lead when it is back in the right position.

If everything seems OK, you need to make sure the spark is happening at the right time - is it possible that a crankshaft woodruff key has sheared?
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Honda Varadero XL125(V8)
www.TheFutureIsHere.eu

[sirus2014]

Ok i have got it starting but now have a new problem there is a really loud knocking noise coming from the engine where the crank shaft is any ideas?

[mattfender666]

i would check the clutch, the basket bolt could be loose, if not check rotor.

[sirus2014]

Hi not sure it would make that loud of rattling though it's like metal tapping metal

[Paddy Blake]

I have felling the big end is done in.

Take the plug out.
Turn the engine just past top dead centre.
Put a screwdriver in the plug hole and push on the top of the piston while holding the flywheel.
If the piston moves then the big end is gone.

[sirus2014]

Thanks for the tip will check that 2mo hope it's not though think that's to much of a job for me to take on lol

[mentalboy]

I'm sorry for your woes but it doesn't sound like you are going to have much luck with this one, big end does sound likely.

Just how old is the bike and how many miles/km's does the odometer say it's done?



I'm sorry but this did bring a smile to my face. Your bike blew over because it was light, if it were heavy it wouldn't have blown over in the first place! Unfortunately a common problem with mopeds and smaller capacity bikes and one which hopefully won't catch you out again.

[........................]

[sirus2014]

yeah big end gone

[sirus2014]

Na not a light bike it went over coz i didnt put on the stand proper. dude over the road from me was hollering at me, so i got of the bike to see what he wanted then turned out he was just playing silly buggers to annoy me then bang bike went over. livid