my bike won't start!

[twlou]

When the engine cut out on you what actually happened? Any loud noises or whatever?

Stupid question...but I'll ask anyway....is your oil level OK. You haven't lost all the oil have you?

The compression can be checked using a checker (around £20) but you can just pull the plug out and spin the motor briefly and put your finger over or near the plug hole. You'll feel the pulses of air when the piston comes up. This is not an accurate way of checking it, but it'll indicate if you've got some compression: ie. not holed a piston or dropped a valve.

Actually maybe you should open the rocker covers and just check that a valve hasn't dropped before going too far. That noise when you were trying to bump it was a bit loud for just poorly adjusted tappets.

 

No there were no loud noises although thinking back I do recall a rapid tapping noise when I was riding it. The bike literally cut out, had no response from the throttle but lights still worked. When I tried starting it again, what you see in my first video is what happened. There's definitely some sort of compression there as when I was peering inside the plug hole I could feel air blowing in my face

I'm not sure I know what you mean by rocker cover?

[twlou]

Stupid question...but I'll ask anyway....is your oil level OK. You haven't lost all the oil have you?

 

No, there's plenty in there

[Bogof]

Time to call in the professionals maybe?

[Fozzie]

Pull off the top end... Sounds like a valve or a piston ring has gone walkies

[Mawsley]

Hooked it up to my car, didn't do anything. Still doesn't start.

Have the car running and being revved

[Colin the Bear]

Hooked it up to my car, didn't do anything. Still doesn't start.

Have the car running and being revved

 

http://i195.photobucket.com/albums/z28/Colin_the_bear/69.gif

Not funny

[twlou]

hey everyone. took the valve covers off this morning and this is what i found:

1. took the camshaft cover off and it looks as if the timing chain had been rubbing on the inside somehow

http://i1082.photobucket.com/albums/j374/e30lou/SANY0225.jpg

2. took the valve covers off and looking at the exhaust valve, the screw was damaged/cracked. it was sat very tightly against the valve tip so i tried adjusting it but the valve kept moving up with the screw and there was never any clearance

http://i1082.photobucket.com/albums/j374/e30lou/SANY0220-1.jpg

i also noticed the top of the exhaust valve cover had a little indent inside it which is where i think the top of the screw had been hitting it

i made sure the piston was at TDC before i touched the valves. i could also see both valves move down and up so there's no issue there.

apologies on the size of pics

[Fozzie]

I cant tell you from those pictures alone but the chain marking the inside is normal. Just needs to be ever so slightly slack and that will be enough to hit the outer casing, I've found scratches on the inside of a bike like that before...

But I can't quite tell from the way you have photographed the valve (or maybe I cant understand what I'm seeing) but what does the manual say on the matter of the valves?

[twlou]

http://i1082.photobucket.com/albums/j374/e30lou/SANY0220-1-1.jpg

where i have arrowed it you can see the damage to the adjustment screw. you can't put even the smallest feeler gauge in between the bottom of it and the top of the valve. if you undo the 10mm bolt and try to turn the adjustment screw(it should be easy if the intake one is anything to go by) it's very difficult, i had to use pliers. as you turn it the valve moves up with the screw, as if it's trying to push itself against it. hope that makes sense

[Mawsley]

Hooked it up to my car, didn't do anything. Still doesn't start.

Have the car running and being revved

 

http://i195.photobucket.com/albums/z28/Colin_the_bear/69.gif

Not funny

 

Wasn't meant to be funny.

A battery with low charge wouldn't have the oomph to fire up the bike without current being drawn from a running engine.

[Bogof]

Hooked it up to my car, didn't do anything. Still doesn't start.

Have the car running and being revved

 

Shouldn't need to rev it with an alternator on the car

[twlou]

ok, i went to my local garage(thanks chopster125 ) and we had a little chat. he agrees with the electrical issue, change the ignition coil so tomorrow when that arrives i'll do that. when i described the noise from me bump starting it he said it might be that the starter clutch isn't engaging hence that loud clicking noise. so had a look at the manual.......looks like a big job unless anyone can ease my mind

failing tomorrow's lecky stuff, i'll have to just bite the bullet and take it to him. he's even offered to pick it up for me! will keep you all posted.......thanks so much for everyone's input so far, much appreciated

[Guest]

ok, i went to my local garage(thanks chopster125 ) and we had a little chat. he agrees with the electrical issue, change the ignition coil so tomorrow when that arrives i'll do that. when i described the noise from me bump starting it he said it might be that the starter clutch isn't engaging hence that loud clicking noise. so had a look at the manual.......looks like a big job unless anyone can ease my mind

failing tomorrow's lecky stuff, i'll have to just bite the bullet and take it to him. he's even offered to pick it up for me! will keep you all posted.......thanks so much for everyone's input so far, much appreciated

IM GOOD FOR SOMETHING..YAY!

[Colin the Bear]

From what you've said in earlier posts , sounds like you have an exhaust valve problem. The spring holds the valve shut, so if the valve is rising with the adjuster it's not closed. The gap is to ensure the valve is closed. If the valve doesn't close, theres no compression and so the engine won't run, which may well explain the strange noises. Get your mechanic to check here first.

[twlou]

From what you've said in earlier posts , sounds like you have an exhaust valve problem. The spring holds the valve shut, so if the valve is rising with the adjuster it's not closed. The gap is to ensure the valve is closed. If the valve doesn't close, theres no compression and so the engine won't run, which may well explain the strange noises. Get your mechanic to check here first.

 

Ah that's interesting then. So why would the spring be holding the valve shut?

[Colin the Bear]

The spring holds the vave in the closed position and the rocker opens it at the right thime. You really need to read your manual. It's very hard to fix any machine if you don't understand first principles. I think It's bogof who has an avatar that shows how it works. Suck , squeeze, bang, blow.

http://auto.howstuffworks.com/motorcycle1.htm

[twlou]

The spring holds the vave in the closed position and the rocker opens it at the right thime. You really need to read your manual. It's very hard to fix any machine if you don't understand first principles. I think It's bogof who has an avatar that shows how it works. Suck , squeeze, bang, blow.

http://auto.howstuffworks.com/motorcycle1.htm

 

oh i understand how the engine works which is why i'm not sure why the spring is still rising whilst i'm loosening the adjustment screw. it should be exactly like the intake valve, if i loosen THIS adjustment screw the valve will not move, the spring doesn't extend so there is a gap UNLIKE the exhaust valve.

my understanding is when the valves are both shut the valve springs will be fully extended, not compressed like when they are pushing the valves open. so if this exhaust valve spring continues to extend then i'm going to assume either the valve is bent or the spring needs replacing

i'll put a video up tomorrow if it helps to explain things clearer

[Bogof]

my understanding is when the valves are both shut the valve springs will be fully extended, not compressed like when they are pushing the valves open. so if this exhaust valve spring continues to extend then i'm going to assume either the valve is bent or the spring needs replacing

 

If they were fully extended there'd be no pressure on the valve to keep it shut

[fredc]

You might have lost the head off the valve

[twlou]

this is as best as i can describe what's happening, so please bear with me:

1. loosen

2. turn anti-clockwise

3. bottom of screw moves up

4. top of spring also moves up

there is never any clearance. i can turn that screw all the way up and the top of the spring will sit against the rocker arm. if i carry out the same principle on the intake valve i will get a gap/clearance and the top of its spring does not move

http://i1082.photobucket.com/albums/j374/e30lou/SANY0220-11.jpg

[twlou]

my understanding is when the valves are both shut the valve springs will be fully extended, not compressed like when they are pushing the valves open. so if this exhaust valve spring continues to extend then i'm going to assume either the valve is bent or the spring needs replacing

 

If they were fully extended there'd be no pressure on the valve to keep it shut

 

i was confused by what you were saying as i was sure that the spring compresses to open the valve and remains extended to close the valve. i've searched the web and several videos/animations confirm this.

for example:

http://youtu.be/UjcIJJnpprs

[Guest Hodgy]

At the top of each valve is a clip, called a 'collet' that stops the spring coming off the top of the valve, perhaps you have lost this somewhere, meaning that the spring is able to come right off the valve?

Just a thought. Hope you get it sorted

[Fozzie]

Show a picture of the other side!

Use macro mode on the camera and get close ups of the valves etc so we can see as much, as clearly as possible. There has to be something wrong with the valve to explain why it is doing that.

[eastanglianbiker]

did you just try getting a gap on the valve,you need to make sure camshaft is in correct part of its cycle before you will get a gap,but as others have said it sounds like you might of broken a valve or it has burnt into the cyclinder head in which case you wont get any kind of gap

[twlou]

At the top of each valve is a clip, called a 'collet' that stops the spring coming off the top of the valve, perhaps you have lost this somewhere, meaning that the spring is able to come right off the valve?

Just a thought. Hope you get it sorted

 

http://i1082.photobucket.com/albums/j374/e30lou/SANY0229-1.jpg

Hodgy, you were absolutely right! The collet was damaged as you can see from the pic. Roy from the bike shop(RP Motorsports) has literally just come and taken the bike away. I had everything exposed so he could instantly see the problem. also pointed out how freely the valve moved from side to side. he said this was why the bike would have cut out in the first place, no compression, and of course why it won't start!

i'll hear back later on today from him with a full and final verdict. will let everyone know as i know in my experience it's always nice to know what the problem was and how it was solved for other people's sake.

thanks so much for everyone's support and guidance