Had a problem with the shims and sheared of exhaust studs which have been fixed by a mechanic friend. Bike started first time at his house. Went to pick it up, popped it on the trailer, then drove 30 miles home. Tried to start when i got home but it really struggled to start. But once started i left it running for 20 or so minutes. Now the fucker wont start. Aaaaarrrggghhhhhh

First things first, what position should the fuel tap be in........should it show "ON" at the 12 o'clock position

Secondly it turns over but does not bark into life. I can smell petrol and have removed the spark plugs which are brand new and they are fine. I think it may be a electrical fault somewhere but i have no idea where to start.

Was hoping to do some trackdays this month so some help from you experts would be greatly appreciated.

the tap, when you sit on the bike is turned towards the front of the bike. anti clockwise if you are looking straight on at it.

Check you have a fuel flow - the vacuum might be loose, split or other.

what does it do when it is not starting?

Does it turn over? does it turn over fast enough? have you tried bumping it? hows about fresh fuel/enough fuel?

Check the battery voltage while you crank. Should turn over nice and fast as CMS says. If your battery is a bit weak push starting it will give a stronger spark and possibly a better spin. Jump starts from a car or something are preferable (while running, more juice)

Fuel tap should be ON, or RES if you're low on juice.

There are tricks to see if you're getting sparks, like holding the plug on the frame with a rag over the hole. But don't follow my incomplete inexperienced advice on that.

Also check for fuel flow as CMS says. Either your tap has been modded and will flow fuel when the tap is open, or will need a vacuum from the little vacuum tube from the engine.

U can also play with the choke while cranking, and try cracking the throttle a bit to see what she likes.

Always crank in neutral with lights off. Engine spins easier in neutral than in gear with clutch pulled.

I know this may sound stupid, but have you checked the kill switch? My bike sounds like it's ticking over even with the kill switch in the off position.

Right guys i've been away camping all weekend so not had chance to answer any of your questions

CMSMJ1 - Do i assume that "ON" should face the front then? I have flow, the vacuum is tight and not split. When i hit the start button it cranks over but does not bark into life. I can smell petrol so the tap is fine, that is when i know which bloody position it's meant to be in!! It has a full tank of fresh fuel. Haven't tried bumping it off yet because i wanted to know what position the tap should be in first. I think it's electrical but i'm no electrician and i've read your thread on here when you were struggling to get yours started so i thought you would be the expert on this!!

Lope - I have no idea of how to check the voltage of the battery while you crank it, guidance would be appreciated . I have the battery on a 3sp optimate and that tells me the battery is fine and i had it on charge for a full week before trying to start it with no luck. Advice on checking the spark would be good. No tap mod, fuel comes out ok and vacuum is on and secure. played with choke and throttle but no life in her yet. No lights on bike and it was in neutral.

Challymo - I'm stupid but not that stupid

right then..plugs!!

If you got fuel, got a working CDI etc and the carbs want to let some air in...then you could do yourself a real bit of good work and get some new plugs.

Smelling of fuel makes me think that you're going to have flooded it...so killed the plugs.

Graeme France has had some killer deals on the ER9EH for 4 so might be worth getting in touch.

CMSJMJ1 - The plugs in mine are brand new ER9EH's and i do think i flooded it trying to start it. I need to push it off to see if it will go but i can't do that until i know the correct tap position and i get some help cos the wife aint up to it

What position is your tap in?

Right i now know the correct tap position. Need to bump it off at the weekend and i'll let you know how it goes.

I don't understand all the confusion about fuel tap position. My NC24 has clear markings for RES OFF ON (down back up) surely the NC30 is as simple?

have u disconnected the fuel tank and tried filling a jar with petrol from your tank? might be worth it.

to measure the battery voltage you get a multimeter set it to volts (anything above 15, usually 20) then hold the red probe on the battery + and the black on the frame somewhere on a bolt or something.
a digital multimeter is a brilliant investment (cheap ones can go for 7 quid) without it you have no clue what condition your battery is in, state of charge, if its charging etc. u can get them online, electronics store, maybe an auto spares shop/hardware store.

try bumping it. you get a stronger spark and can give the motor a nice push. i stand on the left of the bike with it in 2nd gear, kickstand up, holding the clutch, run forwards with the bike, then lie over the seat while still holding the bars, and release the clutch for half a second. usually does the trick. the idea is to make the bike easy to push fast, and also give the rear wheel traction when u bump. it can take a few attempts if your carbs are not set up nicely. u can break a good sweat :)
If available, its better to just jump start it from a car.

I was once scratching my head while the bike wouldn't start with the kill switch off. someone else had turned it off.. I never use it.

you can ask the other guys how to do the spark test. something like covering the hole with a rag, or better yet leave the spark plug in, and test the lead on a spare spark plug. touching the side of the spark plug on the frame while you crank to see if you get a spark. just wear rubber gloves and shoes or something. don't shock yourself :) and if you do you'll most likely live, but try it at your own risk
a good rule of thumb with electricity is not to provide yourself as a path for it to flow through to get where it wants to go.
so the spark lead wants to get to the frame, the tip of the spark plug wants to get to the frame, the side of the spark plug wants to get to the frame, and possibly into the ground also, so don't put yourself inbetween the two by holding the frame with one hand and the spark plug with the other, if you follow my drift.

if you get sparks and fuel flowing, your carbs are probably a mess.
is it possible that his spark plug wires are in the wrong order?

Lope wrote:I don't understand all the confusion about fuel tap position. My NC24 has clear markings for RES OFF ON (down back up) surely the NC30 is as simple?

The nc30 has these 3 positions written on the fuel tap.

If you're not using a genuine seat unit you might be missing the marker that the appropriate wording points to.