Ok so my pit bike has stopped starting - for some reason?!
I’ve replaced the spark plug (still no spark), added more engine oil, more petrol, looked around it but i’m no professor.
Can anyone help?
I’m no genius when it comes to things mechanical, but I’m guessing that might be the source of your problem right there.
How is the plug lead?
And whatever machine creates the spark on your motorb*ke?
(Distributor?)
I’ve rode motorcycle’s for most of my life, I’m no genius at fixing them but I can ride them pretty ok. 
First off I need to know what kind of bike it is and the year.
Just going off of what you said it could be any number of things. Don’t just add oil, that couldn’t possibly fix a spark or ignition problem. Infact if anything you’ll just end up putting too much oil in your bike. The spark plug change was a good idea, but like I said it could be any number of things. I really need to know what kind of bike it is then maybe I’ll be able to help you a little more.
P.S. post a picture of what your previous spark plug looked like
I don’t see any damage… and can’t think of any reason why there would be (i’ve checked the spark by holding it on the engine without the cap on(none))
I’m afraid I don’t know what a distributor is, but my dad said something about whether it was a inner roter, or it had a battery (which it doesn’t)… or some gibberish like that!
I should take it to the motorbike shop in town, I just have no way of getting it there 
Cobra 125
Well I think it’s some chinese thing or something (which you may have never heard of) but it was cheap so…
Here’s where we got it from: http://funbikes.co.uk/p-the_new_cobra_125cc_pit_bike__black-582.aspx
and here’s a video of me riding it just for the record: http://www.youtube.com/watch?v=uyDPVc6z15Q
The old spark plug was as normal but with some black /brown muck on it, which i cleaned off with a wire brush.
Have you checked all the fuses?
The spark plug may be faulty - even if it’s a new one.
The plug cap may be faulty, or loose. Check it thoroughly.
The HT lead (the lead joined to the plug cap) may be cracked internally. Can you borrow an HT lead from a similar bike? The lead can usually be easily replaced.
The lead comes from the coil. A coil either works or it doesn’t. Check all the connections. If you know how, or know a man who knows, you can check the coil.
I guess the bike’s a single, right? Then you won’t have a distributor cap, but you will have points. They are cheap and easy to replace, but you will need the manual and some feeler gauges.
Failing that, you may be looking at battery and alternator problems.
Adding too much oil can be bad. If there’s an excess of oil in the system you could rupture a seal… the engine can tolerate some overfill, but if you flood the engine with oil, it’s gonna end up in places where it shouldn’t be.
The ingredients needed to run any internal combustion engine are air, fuel and spark. You gotta check these three paths. Of course, since you don’t have spark (how did you check this?) that’s the first place to look. Is your cable broken? Is your regulator / coil busted? Follow the wire from the spark plug all the way back to the magneto and check any components it is connected to.
The simple way to check for fuel is to turn the engine over a few times as if you’re starting it and sniff around the exhaust for fuel. You’ll have flooded the engine, but at least you’ll know gas is getting there. No gas? Your carb may be clogged. Take it off and clean it out with some carb-clean. Make sure to take out the needle (be careful!) and inspect the jet… that’s usually the first thing to clog. If you’ve never taken apart a carb before, go very slowly and take lots of notes / pictures.
Checking the spark plug is much like checking your body temperature with a thermometer; it tells you a lot about the health of the engine. Check out this page:
Diagnostic aid for spark plugs
If that “muck” is dried on, then it sounds like you’re running the engine too rich… replace the plug and adjust the carb. Also, the engine may not be getting enough air. Did you check / clean out the air filter?
If the “muck” is oily, then you’ve got way too much oil in the engine and you may have already damaged it. It’s possible that you’ve damaged the piston ring and can no longer achieve the compression necessary to run the engine. This, unfortunately, requires a significant rebuild before it may run again.
Remember… air, fuel, spark! Check these out and let us know…
I un screwed the plug, and held it against the engine and kicked the kick start…no spark.
I’ll try and check everything else you guys said, but some of it I think just can’t have happened.
I did not put too much oil in, it is now half full (/empty)
- I don’t believe I have a battery.
Honestly I never have torn down into small pit bikes like the one you have.
Theres only a few things you can do really until you need to take it in and have it looked at. First off, make sure its not flooded, aka don’t gold the gas on while trying to kick it. Then just drain you gas and oil and fill it back up to the normal levels. Also be sure to drain the gas out your carb. If you want you can check your ignition wiring and make sure it all looks good. Oh yeah, make sure the gas is one too;)
Oh yeah I almost forgot, push start it! just have somone push you, or better yet find a hill that you can coast down to get some speed, then just shift down and it should start right up. If not you have problems and need to take it in. I would definatley try this right after you drain you fluids.
I’ve already tried bump starting it, it wont kick over- it just konks out and doesn’t take any accelleration.
Is it an easy job to drain the carbareta!? I don’t wna go breaking anything more…
Pardon me for being cynical this evening, but I’m getting the feeling this lad is taking the piss.
Take it to a qualified mechanic for futher attention.
I never demanded any replies, I just asked in case anybody wished to help.
Do I have to argue about this with you yet again?