engine stop while i was riding my bike!

[vmlp]

Hi all,

I recently did valve clearance adjustment. I kept 0.12mm - intake and 0.15mm for exhaust. Also done CAM timing as per manual (TDC #2, EX mark and IN mark was lined up to the edge of engine top cover and the chain link counted from EX mark to IN mark were 33 links).
Today, I was going on local street, after 15 minutes of ride the engine stopped and upon trying to start it make some clicking/knocking sound and the engine won't start!!!

Anybody had such experience? What would have happen?
In mean time, I am going to open the engine cylinder head cover to examine.

Any inputs on this would be appreciated.
Thanks in advance.
vmlp

[Motofool]

Rocker's nuts under-torqued?

Did you service the cam chain tensioner?

[alex.s]

maybe someone is trapped inside and is trying to get out

[ninja_thresh_hold]

you took out the battery, more than likely, so my question to you is did you set your battery on cement? if so that could have grounded the battery out and you'd need to charge the battery to a full charge.

[vmlp]

Thanks Hernan, Alex, Eric for your response!

I found 6 of arm-rockers were broken off!!!! Only 1 pair of Exhaust valve on cylinder# 2 are intact.
and one of broken arm-rocker fallen in to cam chain well.

May be something went wrong during valve clearance adjustment?
I had set them at close to the upper limit (0.12mm intake / 0.15mm exhaust side).

What else could cause the valve arm-rocker broken?

Thanks,
Vmlp

[Motofool]

That is a massacre !!!

Rocker is a fusible that breaks when the cam pushes and the valve can't slide freely.

Did you service the cam chain tensioner?
Did you rotate the engine by hand several times after finishing the adjustment (clearance and tensioner)?

Have you rechecked the CAM timing?

[FrugalNinja250]

Originally Posted by vmlp

Thanks Hernan, Alex, Eric for your response!

I found 6 of arm-rockers were broken off!!!! Only 1 pair of Exhaust valve on cylinder# 2 are intact.
and one of broken arm-rocker fallen in to cam chain well.

May be something went wrong during valve clearance adjustment?
I had set them at close to the upper limit (0.12mm intake / 0.15mm exhaust side).

What else could cause the valve arm-rocker broken?

Thanks,
Vmlp

Before you go any further, once you've cleaned all the metal you can find from the cam chain well, you should first test that the cams turn with the motor, and then do a compression check. If you had a cam chain problem that resulted in the valves hitting the pistons then the motor is basically done for, time to start looking for another one.

[vmlp]

Originally Posted by Motofool

Rocker's nuts under-torqued?
Did you service the cam chain tensioner?

Rocker's nuts under-torqued?
I think i did over torqued!
Did you service the cam chain tensioner?
Installed new one with synthetic greace applied on bearing ring

I believe, the cam timing set went wrong!
I did as per the manual. Set @ TDC-2, and on exhaust cam sprocket - EX mark set on line of cylinder head edge and IN mark for Inlet sprocket, also verified the cam chain links -- from EX mark to the IN mark - 33 links as per manual.

I would appreciate if someone post the cam timing set-up procedure for 2007 Ninja EX-250 here or attached as a link.
I will compare with mine.

If the valve clerance set on higher limit would cause such failure?

Thanks,

[vmlp]

Originally Posted by FrugalNinja250

Before you go any further, once you've cleaned all the metal you can find from the cam chain well, you should first test that the cams turn with the motor, and then do a compression check. If you had a cam chain problem that resulted in the valves hitting the pistons then the motor is basically done for, time to start looking for another one.

Thanks FrugalNinja250!
Yea...I could not find 1 piece of broken rocker -- probably dropped in cam chain well. I will try magnetic bit extension to catch that. I am going to do oil change just in case.
When i did cam timing adjustment, I did tried rotating the cranck shaft but it was in counter-clock wise. Is it right way to check it?
Can i leave the valve cover open and fire-up the engine to see all valve operates fine?

If anyone has cam timng set-up procedure for 2007, Ninja EX250, please post it here or link here please.

Thanks in advance,
Vmlp

[Motofool]

Originally Posted by vmlp

Rocker's nuts under-torqued?
I think i did over torqued!
Did you service the cam chain tensioner?
Installed new one with synthetic greace applied on bearing ring

I believe, the cam timing set went wrong!
I did as per the manual. Set @ TDC-2, and on exhaust cam sprocket - EX mark set on line of cylinder head edge and IN mark for Inlet sprocket, also verified the cam chain links -- from EX mark to the IN mark - 33 links as per manual.

I would appreciate if someone post the cam timing set-up procedure for 2007 Ninja EX-250 here or attached as a link.
I will compare with mine.

If the valve clerance set on higher limit would cause such failure?

Thanks,

I asked about the tensioner because something that happened to me during the last valve adjustment:
Did remove the chain protector in order to measure the wear of the chain.
Did dissemble, clean and lubricate the tensioner.
Did re-install the tensioner and rotate the crank counter-clockwise.
I witnessed in horror that the chain jumped several times over both sprockets, messing up the timing.

I found out that the tensioner was not pushing the rear rubber guide strongly enough, allowing the chain to jump when the springs-cams turned the sprockets.

After dissembling the tensioner and re-installing it again, the chain tension returned to normal.

I did re-time the cams as you have explained (all being seen from the left side of the engine).

The valve clearance couldn't cause the problem; its only function is to compensate the dilatation of the mechanism with heat, so the valves can close completely.

As explained above, a wrong timing would push the valves into the combustion chamber when the pistons are close to the top, hitting them.
Many times that crash results in bent valves and broken pistons, if the rockers don't yield first.

Best!

[vmlp]

Thanks Hernan,
Good point! I will make-sure & verify the cam timing/chain movement by rotating the cam-shaft counter-clock wise.
My cam timing procedure is correct, right?

Do i need to check the conditions of valve?
How can i do with minimum work? .. I don't want to open all apart and get screwd-up something else!!!

Thanks again,
Vmlp

[Miles_Prower]

did you run out of gas? lol

[Motofool]

Watch how the whole timing thing works:

http://www.animatedengines.com/otto.html

First and after eliminating all metal debris from the engine, I would check if timing is as you last adjusted it.

I would be more worried about the two valves which rockers didn't break off.

The proper way to verify damage is dissembling the top and sending it to a machine shop.

Without going that expensive route, you could check a few things:

1) If the stems of the valves have been bent: Visually check if any valve is not returning all the way back: bad news if so.

2) If #1 or deformed valve lip or broken piston: Run a leak test with all the valves of that cylinder in closed position.

http://www.dansmc.com/leakdown.htm

[n4mwd]

When you overtorque the rocker nuts it snaps the little keeper feet off. This sets up a chain reaction. First that one wiggles loose. Then it works its way under the chain and sprocket causing the sprocket to hop a link. When that happens, the pistons impact the valves (The Ninja is an interference engine). When the valves are impacted, it breaks off the rest of the rockers. The fact that you had a few survivors amazes me. You need to remove them and check them over for any signs of bending.

Also, as Motofool said, you need to inspect the valves and pistons for signs of impact damage. You might be able to get away with one of those inspection cameras that can fit down the spark plug hole, but sadly, its best to pull the head and replace the $25 gasket when you put it back.

[vmlp]

Originally Posted by n4mwd

When you overtorque the rocker nuts it snaps the little keeper feet off. This sets up a chain reaction. First that one wiggles loose. Then it works its way under the chain and sprocket causing the sprocket to hop a link. When that happens, the pistons impact the valves (The Ninja is an interference engine). When the valves are impacted, it breaks off the rest of the rockers. The fact that you had a few survivors amazes me. You need to remove them and check them over for any signs of bending.

Also, as Motofool said, you need to inspect the valves and pistons for signs of impact damage. You might be able to get away with one of those inspection cameras that can fit down the spark plug hole, but sadly, its best to pull the head and replace the $25 gasket when you put it back.

Thanks Motofool & n4mwd for your responses.
I believe the theory you explained is what happen with my bike! One of rocker-arm broke and fell in to cam chain well and that caused the cam sprocket to hop a link and eventually I got 6 rocker-arms broken. I rode the bike for at least 8 kms after valve clearance adjustment service and that distance was enough for such damage.
Now I got the new rocker-arms but I have 1 rocker-arm got stuck to the crank-shaft(gear)! I am having trouble getting that out! I think the next option is to take the crank=shaft assy. apart, right? OR I am thinking to take it to the mechanic shop. But the problem is the shop is at least 30kms away!!!
Also I am not sure how much it would cost me to have this fixed.
Anybody has any idea about the cost?
Thanks,
Vmlp

[vmlp]

Originally Posted by Motofool

Watch how the whole timing thing works:

http://www.animatedengines.com/otto.html

First and after eliminating all metal debris from the engine, I would check if timing is as you last adjusted it.

I would be more worried about the two valves which rockers didn't break off.

The proper way to verify damage is dissembling the top and sending it to a machine shop.

Without going that expensive route, you could check a few things:

1) If the stems of the valves have been bent: Visually check if any valve is not returning all the way back: bad news if so.

2) If #1 or deformed valve lip or broken piston: Run a leak test with all the valves of that cylinder in closed position.

http://www.dansmc.com/leakdown.htm

Thanks Motofool!
If i get the piece of rocker-arm out of cam chain well, I will put everything together and see how valve/cam moves. BTW Do you know how much this repair would cost?
Thanks,
Vmlp

[Motofool]

Originally Posted by vmlp

.......
Now I got the new rocker-arms but I have 1 rocker-arm got stuck to the crank-shaft(gear)!.....
Also I am not sure how much it would cost me to have this fixed.
Anybody has any idea about the cost?
.....

You are welcome.

Where exactly is the debris at?

I have no idea about the cost; most shops charge according to the time and parts that solving the problem costs.

Labor alone here in the States is around $60~75 per hour.

[n4mwd]

Originally Posted by vmlp

Now I got the new rocker-arms but I have 1 rocker-arm got stuck to the crank-shaft(gear)! I am having trouble getting that out! I think the next option is to take the crank=shaft assy. apart, right? OR I am thinking to take it to the mechanic shop. But the problem is the shop is at least 30kms away!!!
Also I am not sure how much it would cost me to have this fixed.
Anybody has any idea about the cost?
Thanks,
Vmlp

You need to take the clutch cover off. (You'll also need a new gasket and a can of gasket remover and a brass wire brush to get the old one off.) Then you need to take the clutch basket off - 4 bolts plus a 100# torque nut. Harbor freight sells the socket for that. This will give you clear access to the crank gear and sprocket. You you should be able to get to most of the debris from there.

On the chance that some went into the engine core, you should be able to fish it out with a magnet. Just don't lose the magnet in there because if not recovered it will end up stuck to the crank and cause even more damage.

[vmlp]

Originally Posted by Motofool

You are welcome.

Where exactly is the debris at?

I have no idea about the cost; most shops charge according to the time and parts that solving the problem costs.

Labor alone here in the States is around $60~75 per hour.

Thanks motofool!
The part of broken rocker-arm is stuck to the teeth of the crank gear. I can see it from top. I need to use some force to get it off from the gear teeth - probably the long flat head screw driver would do it.I will try it tonight if possible.
I will see if the local mechanic can provide the estimate on it.

Thanks again,
Vmlp

[vmlp]

Originally Posted by n4mwd

You need to take the clutch cover off. (You'll also need a new gasket and a can of gasket remover and a brass wire brush to get the old one off.) Then you need to take the clutch basket off - 4 bolts plus a 100# torque nut. Harbor freight sells the socket for that. This will give you clear access to the crank gear and sprocket. You you should be able to get to most of the debris from there.

On the chance that some went into the engine core, you should be able to fish it out with a magnet. Just don't lose the magnet in there because if not recovered it will end up stuck to the crank and cause even more damage.

Thanks n4mwd,
Unfortunatelly, We don't have that Hardware store here in Toronto, Canada.
I will see if i can remove the stucked rocker-arm off from the crank-gear teeth.I can see it from the top and going to use the long flat head screw driver.
Thanks for the support,
Vmlp

[n4mwd]

A mechanic will probably tell you that the cover has to come off. The problem is that you can't really see what kind of damage has been done without a good visual inspection. The gasket costs about $15, the remover is about $10 and the brass brush is about $3. The 27mm socket was about $4 at Harbor Freight. You don't have to go there because there are other stores that sell metric sockets, its just that HF is cheaper than most other stores. You might be able to order online here.