Jump to content

Bike wont start


Nox Arcarna
 Share

Recommended Posts

Was recently doing some self servicing on the bike and decided to get a new battery for it since the old one was well, old and wasn't charged. I would have charged it but I thought that I may as well just get a new battery for it and charge that one up like yeah I had money to waste and a tonne of it so I bought a shit load of stuff like muc off, new oil, got a new rear tyre because the tread had gone on the other, new brake shes for the front and rear, a headlight - lamp upgrade and so on.

I had also finally got the time to put my panniers on and top box because over the Christmas period I plan on doing quite a bit of touring around parts of south Wales regardless of the weather conditions :D


Right down to the deal!

I put the new battery in and connected it up, installed the new light builb, fitted the new rear tyre and brake shoes for both brakes, changed the oil and cleaned & adjusted the chain.

Now when I tried starting the bike it simply wouldn't start, it would try to but wouldn't. I thought for a moment or two over what the problem could be...There is petrol in the tank, the battery was connected right, the light builb is the correct wat/voltage.


At first I thought it was the spark plug but then I had changed that last week.

Can't be the oil because its the correct type/stoke oil.


I have hit a damn here folks, I have no idea what the problem could be.

I've tried priming it as well but still doesn't work and the bike is in neutral when I try to start it.


Any ideas?

Link to comment
Share on other sites

If its injected it must have something detecting both spark and fuel timing. Generally crank angle sensor but can be cam sensor. Tends to be crank rather than cam tho to remove the change in timing due to chain/belt flex and stretch. Older engines with injection sometimes used a Hall effect or reed switch inside the distributor but these days it's coil packs not a dizzy :)

Link to comment
Share on other sites

If its injected it must have something detecting both spark and fuel timing. Generally crank angle sensor but can be cam sensor. Tends to be crank rather than cam tho to remove the change in timing due to chain/belt flex and stretch. Older engines with injection sometimes used a Hall effect or reed switch inside the distributor but these days it's coil packs not a dizzy :)

 


majority of bikes its on the cam maybe some newer ones could have on the crank :wink:

Link to comment
Share on other sites

I build car engines so admit I'm not a bike expert. The only bike loom I ever made was for a vmax and I can't recall where the pick up was. I also did a loom for a 750 but can't recall if it was zxr?? That had a crank sensor.

Either way, has that been disturbed where ever it may be? Lol


Test for a spark first. Can u smell fuel from exhaust? Us it trying to fire?

Link to comment
Share on other sites

cars arent bikes!!!


I have an injected bike and have worked on countless injected bikes and not come across a crank sensor yet


they use cam sensors as they are high up out of harms way ie water! they are delicate stuff as you should know putting it low down in line with all the shit is just asking for trouble!!


your wasting your time comparing them to cars they arent cars they are bikes!

Link to comment
Share on other sites

Provided the OP hasn't misspelled AND is grammar proficient, they have state they change THE spark plug last week.......................so its got one cylinder whatever it is :wink:


Narrows it down a bit? 8-)

Link to comment
Share on other sites

Thanks for the attitude stu!

 

No attitude its the way you read it :wink:


I know my stuff when it comes to bikes!


like I said majority dont have a crank sensor there is some that do wait to see what bike it is like i first asked and then find out if it has one


oh and if they have one they are built in to the crank case out the way

Link to comment
Share on other sites

Fair do's, the Internet is a bit like that some times, that accent or pause intended don't get noticed by others and context changes. A famous example being:

Helping your uncle Jack off a horse.

Is that:

Helping your uncle jack, off a horse.

Or

Helping your uncle, jack off a horse.


Kinda makes a difference and could easily be misread lol.


And back I topic.


What bike is it? :)

Link to comment
Share on other sites

Not sure...but I think he said in the newbies section that he has a CBR125....could be wrong though.... :wink:

I think that the best course would be to check for a spark first as suggested above....then move on from there. Also check some of the more common stuff....ie, Side Stand switch, kill switch, neutral switch etc..... :wink:


As a side issue my bike has a sensor and magnet mounted on the alternator for generating the signal for spark and injection timing......just thought I'd throw that one in.... :wink: :lol: :lol:

Link to comment
Share on other sites

My apologies the bike is a Honda CBF 125, injected and nope I do not believe it to be anything to do with the cam or the carb and I've checked the spark plug and that seems fine. Cannot smell any petrol either though I can when I open up the tank :D, the bike was running fine yesterday so I'm not sure of what the problem could be but I'll take another look at it tomorrow, even if I have to take the whole thing apart to find out what the problem is I will take a look see and try to find that problem and fix it if I can.

Link to comment
Share on other sites

You haven't done something really silly like turning the petrol tap off to remove the tank for the work you have been doing and forgotten to switch it back on? Or knocked the kill switch to the off position while fiddling with the headlight?


Easy done, I know, I have done both before :)

Link to comment
Share on other sites

Well my cbr uses the same sensor for fuel and spark as cars do, it would seem wasteful of bikes don't all do that but I'm no expert :) and as a cbr and cbf are close relatives its a fair bet that's not your problem here.

Fuel pump, relay, fuse and pet would be my first checks. Is the pump tank mounted? Did you unplug it to do spark plug? Is it plugged in and if so is it securely plugged in?

Link to comment
Share on other sites

When you say you've checked the spark plug do you mean that you've taken it out and looked at it or have spun the motor with the plug out and checked there is a spark? Normally if you have a spark and have fuel it should run unless you've not got enough/any compression. Are the connections to the terminals of the battery good and tight? If not the starter can spin the motor but there's not enough voltage to get a decent spark....so it won't fire up. Have you tried bump starting it?

Just a couple of things off the top of my head..... :wink:

Use the KISS principle.....eliminate the easy stuff first....then work up to the more serious possibilities.... :wink:

Link to comment
Share on other sites

right, can we do this methodically rather than randomly guessing?


When you try to start the bike, are the lights on? If so do they dim rapidly? - If they do the battery is out of charge. Other signs its out of charge is the horn does not sound constant and indicators also dim when in use. If they do not come on at all then it may be a fuse/something not connected (battery wrong way round?)


Also, maybe just check all the fuses to be on the safe side before messing around with other things.


When you press the starter switch can you hear it ticking over? (clicking) - if so it is not the kill switch/side stand switch etc and it means its in neutral.

- I am only guessing from the cc of the bike, but you may be new to riding, but if you cannot hear the clicking, have you remembered to pull in the clutch whilst holding down the starter button? I am not sure on the CBR but some bikes have a saftey feature meaning you must pull the clutch in.


If you can hear the starter motor clicking over, the next thing to do would be to check the spark plug (which you say you have) and then see if the hole from which the spark plug came from is wet and smells like petrol. You can try sticking something in the hole (not your penis) and then giving it a sniff


if there is no smell of petrol then we have narrowed it down to being somewhere in the fuel lines/pump/switch etc.


These are just a few things I have learned over the years, but it would help the more experienced guys rule out possibilities and/or get closer to finding a solution.


Unfortunately it can be hard to give help over the net sometimes, it is a lot easier when you can get your hands on the bike and see/hear/smell exactly whats going on.

Link to comment
Share on other sites

The same thing happened to my brothers NSR when he had it. Since his other bike was off the road because an ambulance accidently backed into him he had bought an old NSR off one of his work mates and had to get various new bits and bobs for it. The problem he had with his though was the spark plug and battery ^^

If you have solved the problem already then don't forget to let us know what it was that was causing it in the first place :D


I know I'm late to reply but, better late than never :D

Also you said that the bike would try to start but couldn't? So it wasn't ticking over. Sounds like a definate problem with the fuel pipe/pump.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Welcome to The Motorbike Forum.

    Sign in or register an account to join in.

×
×
  • Create New...

Important Information

Terms of Use Privacy Policy Guidelines We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Please Sign In or Sign Up