Timing belts mess up

[Jungo]

Guys, seems like I mess up my bike. This morning I started to replace timing belts. I followed the procedure to ensure the timing marks on the two pulleys and the T1 line. Also I made a small mark on the crankshaft pulley to make sure of all the pulleys were perfect. I proceeded with the replacement of timing belts, and I was watching at all times by the marks of the pulleys. Once I concluded with the installation of the belts of time, I turned the crankshaft by hand twice consecutively and were perfectly positioned marks.

Then I started to install the radiator back and I turned on the motorcycle. It turned on perfectly on the first try. I left it idle for about 10 minutes. After 10 minutes I started hearing a clicking noise in the area of the valve on the right side. Immediately I turned off the motorcycle. At first I did not know that could produce noise so after checking everything I start the engine again, and as soon as I heard the noise off and proceeded to remove the radiator cap and the timing belts.

Sadly and unfortunately I noticed that the crankshaft pully had shifted a few degrees. I know this is not good news and possibly I destroyed my motorcycle. I removed the timing belts but I noticed that when I try to rotate the crankshaft pulley to put in the mark of T1 I find it very difficult and tough to be getting as close to the mark. When it's close to the mark, it "jumps up" and continues to rotate normally.

I hope that the crankshaft is not bent, otherwise I don't know what to do. I know that this translator may not correctly describe the problem I have, but I can post a video if needed to help better.

Regards.
J

 

[mcgovern61]

It is unlikely the crank is bent....but you may have bent the valves on one head. If the crank was off even one tooth, the pistons hit the valves. The engine should not be toast, but the head making the noise most likely needs the valves replaced. :crying:

 

[Jungo]

It is unlikely the crank is bent....but you may have bent the valves on one head. If the crank was off even one tooth, the pistons hit the valves. The engine should not be toast, but the head making the noise most likely needs the valves replaced. :crying:

Thanks for replying brother mcgovern61. Replacing a valve is better than to replace a crankshaft, at least I am hopeful that just the head.

Any suggestion where to start?

 

[mcgovern61]

Turn the engine over by hand from the stator bolt and listen for which head sounds like the piston is making contact. (You could also do a compression test to see which valves are no longer holding compression, but I would not run the engine anymore since you already know there is a problem.) You will the have to pull that head and check to make sure there is no piston damage.

It is possible that valves could be hit on both heads, but that is unlikely; usually is is on the side that went out of adjustment.

 

[slabghost]

Start over on the belts. Back off all the valve adjusters. Set the belts and turn it over by hand at least 4 times. Checking each time that all the marks are lined up.If I recall correctly T1 mark is for setting one cam and T2 mark is for setting the other. When you are certain all the marks line up correctly. Set the valves to the loose end of adjustment. Again turn the motor over slowly by hand feeling if it turns smoothly or catches at certain points. If it moves smoothly through a couple full rotations. Do a compression check. If all 4 have good compression the valves are probably okay. Start it if all that checks out. Warm to operating temperature. Then another compression check. If all have increased. I'd say you've got a runner.

 

[Steve83]

Since a bent valve can't fully close, the gap between the rocker arm and the valve stem will be much, much wider than normal. I would pull the valve covers and check the valve clearance. If one or more are extremely loose, those valves are probably bent. Oh - sorry Slabghost, but both cam timing marks are set with the crank at the T-1 mark, and "UP" on both sprockets facing up. Great advice otherwise.

I bought an '80 1100 with a broken left timing belt, and all 4 valves on that side were bent. There was no head or piston damage, and after replacing the valves with some used ones I found on ebay, she ran beautifully! I doubt yours will be this bad.

Only turn the engine by hand until you know everything is free and clear. May the Force be with you! (Star Wars...Star Trek...it's all good!)

 

[Bobo]

Start over on the belts. Back off all the valve adjusters. Set the belts and turn it over by hand at least 4 times. Checking each time that all the marks are lined up.If I recall correctly T1 mark is for setting one cam and T2 mark is for setting the other. When you are certain all the marks line up correctly. Set the valves to the loose end of adjustment. Again turn the motor over slowly by hand feeling if it turns smoothly or catches at certain points. If it moves smoothly through a couple full rotations. Do a compression check. If all 4 have good compression the valves are probably okay. Start it if all that checks out. Warm to operating temperature. Then another compression check. If all have increased. I'd say you've got a runner.

+1

Keep the faith, Brother! :good:

 

[joedrum]

okay jungo sheeesh !!!!...one thing for sure you put the belts on right .....it would have never ran 10 minutes with the belt out of time ....you suffered a hanging valve .....im sure its probably sticking down causeing the rough spot your talking about .....all over these forum its suggested that the that belts break and distroy motors its more like this you have a valve hangs and thepiston runs into it and breaks or slips the belt ......im rather sure now you have blown head gaskit to some degree that has cause most your problems as in it running hot and not right ..water has cauze the valve to hang along with the cahange of belts createing a rough valve action than before .....nothing you did wrong really except maybe could have clean everything better and lubed good ....

this is actualy good luck you were smart enough to run it at idle ...and during your run check the valve hung ....causing really no damage to speak of .....if you would have been riding it damage would have been much greater to distroyed....so great move there .....this bike is not distroyed ...

1...ttake plugs out 2....turn crank bolt either way to sink the pistons haflf way down in clinders ,,,thats 90 degrees from t-1 or t-2 at cranh bolt ...one piston hafyway down all down ....loosen all valve adjusters till they are inside the rocker and snug the lock nuts down so they dont get thread off and get lost .....take belts off ....take cam pulleys off ....take heads off ...there are 6 head bolts and one 10mm bolt on the botton of head where the oil flows back to motor from heads ....take pics and put on forum ...before cleaning anything please...this might tell something ...id say the port of the offending valve will be full of something ....oil gas and antifreeze scumbo i bet...... :builder: got some work to do ...your doing good jungo ...dont be down on yourself like i said good move having it run like you did :mrgreen:

 

[dan filipi]

I have my doubts a valve hangup could make the belt slip. The valve just bends too easy.

Running good for 10 minutes then the ticking came on.....hmm.
I'd be looking for why this happened so it doesn't happen again.
Could very well be a valve stuck open but that needs to be verified.
Check that your tensioning the belts properly.
Something caused this to happen, have to get to the root of it.

Have you checked the compression yet?
Do you even know yet if a valve actually IS bent?
I wouldnt be pulling any heads too quickly. Need to get things in order and follow what we're saying so this doesn't happen again.

 

[mcgovern61]

Running good for 10 minutes then the ticking came on.....hmm.
I'd be looking for why this happened so it doesn't happen again.

Agreed! Is it possible the belt tensioner bolts were not tightened allowing the belts to run loose and hence slip? Or.....is it possible the tensioners were tightened before the belts were set correctly?

 

[Jungo]

Guys, I feel loved in this forum. You all are awesome.

Agreed! Is it possible the belt tensioner bolts were not tightened allowing the belts to run loose and hence slip? Or.....is it possible the tensioners were tightened before the belts were set correctly?

Good statement. This is what I did: The pulleys was positioned perfectly. Then I let the tensioner spring "adjusts" the belt, but I noticed that the belts was a little loose. Then I made tension with my hand and tight them.

I will re-read all your post for 10 times so I can make an effective diagnosis.

Thanks, Mcgovern61, Mr. Filipi, my friend joedrum (<= he always motivates me to not be discouraged), Bob, Steve 83, slabghost. God bless you all. :thank_you:

 

[dan filipi]

Scdmarx here had a ticking noise after replacing belts even though it was timed properly. We never did figure out what was causing this.
Just saying strange things do happen.

I would proceed by putting the belts back on with the valve adjusters backed out all the way loose.
Make sure it is in proper timing.
Adjust the valves.
Do a compression check.
Post back the compression readings.

This will determine what to do next.

 

[dlslick]

I don't know the history of your bike but if it has sat for a long time and you are running it on old stale gas that can make a valve stick. I have seen it many times on small engines that are run on old stinky fuel. It always seems to be an exhaust valve.

 

[Jungo]

UPDATE:

Valve adjusters backed out all the way loose. Done

When I tried to rotate the crankshaft it stops at certain point. But just before I loose the valves, I moved the crankshaft and I noticed that left side pulley (cyl 2 & 4) moves a little. Sign of bent valve?

Waiting for instructions...

 

[dan filipi]

UPDATE:

Valve adjusters backed out all the way loose. Done

When I tried to rotate the crankshaft it stops at certain point. But just before I loose the valves, I moved the crankshaft and I noticed that left side pulley (cyl 2 & 4) moves a little. Sign of bent valve?

Waiting for instructions...

If the belts are off then something moved the cam. The only thing I can think of is a piston pushing against the valve.

Ok, with the rockers loose now it should be easy to measure the valve stem height.
If a valve head is bent, the stem will be shorter.

I still think you should put the belts on because once the belts are on and you adjust the valves, it will be easy to see which valve is bent (if any) by the difference in position the adjuster is at.
Then to confirm, do a compression test.

 

[Steve83]

Before you put the timing belts back on, turn the crankshaft so it's halfway between T-1 and T-2, this will put all 4 pistons halfway down the cylinders. If the left cam turns a little, leave it there and turn the right cam until it moves freely like the left one. If the cam turns easily, all the valves should be closed.

With both cams free, the crankshaft should turn all the way around freely. Remove the spark plugs to eliminate compression. If the crank stops at any point, a piston is hitting a valve that's either bent or sticking. DO NOT force the crank if it stops!

If it turns free, follow Dan's instructions.

 

[Anonymous]

maybe a dumb question but you did put the timing belts back on right?

 

[dan filipi]

Before you put the timing belts back on, turn the crankshaft so it's halfway between T-1 and T-2, this will put all 4 pistons halfway down the cylinders. If the left cam turns a little, leave it there and turn the right cam until it moves freely like the left one. If the cam turns easily, all the valves should be closed.

With both cams free, the crankshaft should turn all the way around freely. Remove the spark plugs to eliminate compression. If the crank stops at any point, a piston is hitting a valve that's either bent or sticking. DO NOT force the crank if it stops
If it turns free, follow Dan's instructions.

Be sure to loosen all valve adjusters completely.
That will ensure all valves are closed and prevent bumping any valves when you rotate the engine by hand
If using the crankshaft bolt to turn it, you turn clockwise.
If you turn counterclockwise the starter clutch may engage and give you a wrong feel.

 

[joedrum]

jungo its yime to take the heads off period....thers obviously bent valves period ....this is not that hard to ....you can not chance any more damage period ....dont even thinh about putting the belts back on ....unless im missing something here ...and i could be im rather sick as can be ...its insane to chance this motor any more ...

 

[dan filipi]

My point here Joe, especially since he's feeling an interference when turning the crank with the belts off, is that a piston may be bumping a valve causing that interference.
From what I can tell, what is causing that interference has not been established.
By backing off the adjusters so no valves are being held open by the cam there is no chance for any more damage. If he still feels the interference then we will take it to the next step to figure out which valve may be causing it.
To me it's a waste of time and money to pull both heads if not needed.