something has gone horribly wrong piston hitting valve

[Guest]

So I went to adjust my valves on my 1980 gs1100e. It has the lock nut and tappett screw so no shiming. I adjusted them all to spec which is .003"-.005" cold. Got it done fired it up and ran great. Then it started idling funny and choked itself out. Hit the starter just figuring it was cold, it spun a few times then CLANK! Locked up tight. Took it back apart and every valve would hit I'd loosen one up then the next would hit. I've loosened them all way up and they keep hitting even with a .016" clearance! But it almost looks as if it jumped time somehow which is odd as I just fixed the cam chain tensioner and all the marks lined up when I adjusted the valves but now they don't and the cam chain is tight. I'm stumped short of tearing the motor down what should I do.

[rustybronco]

Re-time it, double check the repair done to the tensioner and reinstall it, re-adjust the valves then do a leakdown or a possibly a compression test looking for any bent valves.

Why did the tensioner need repair?

[Steve]

It is rather common to install the tensioner incorrectly.

Almost everybody understands compressing the plunger, locking it in place, install the tensioner, release the plunger. What they seem to NOT understand is what happens next. After releasing the plunger, turn the setscrew in until it stops, turn it back out 1/4 turn and lock it in that position with the locknut.

Too many times I have seen tensioners that were locked in place, not allowing them to move and do their job.

.

[chuck hahn]

"they DID line up but now THEY DONT"...You answered your own question. At some point after restart, the tensioner caught and the timing jumped. Then, the tensinoer let loose and thats why the marks are off ...even though the chain is tight now.

[m.qualls89]

That's what I figured had happened. And to think this all started with me trying to prevent it jumping time lol. Now my only problem is the rookie uh oh I made when it locked up. I tried to spin the motor with the 19 mm nut on the end of the crank and stripped not the nut but the threads.

[m.qualls89]

Re-time it, double check the repair done to the tensioner and reinstall it, re-adjust the valves then do a leakdown or a possibly a compression test looking for any bent valves.

Why did the tensioner need repair?

The tensioner had frozen up and the cam chain had slack in it.

[chuck hahn]

There is a 19MM aluminum nut and it has a 12MM steel nut in the center...what excatly stripped? The 12MM bolt that goes in to the crank? Or the crank theads themselves?

[Nessism]

Sounds like a bunch of bent valves. Tough lesson.

[chuck hahn]

And a terribly expensive one at that!!!!

[m.qualls89]

There is a 19MM aluminum nut and it has a 12MM steel nut in the center...what excatly stripped? The 12MM bolt that goes in to the crank? Or the crank theads themselves?

The crank threads I'm pretty sure.

[chuck hahn]

Well..I hate to bear bad news, but IF the crank itself is truely stripped..Youre basically bent over a pine stump and theres no Vaseline in sight!!!

[m.qualls89]

What exactly does that nut hold on? I haven't taken it completely off yet.

[chuck hahn]

The 12MM ( the steel one ) holds on the governor behind the timing plate and the whole timing plate assembly to the crank. Take some picstures of itm as is before touchuing anything else and post them up. Itb takes a lot to strip the crank and I am thinking the aluminum nut ripped itself loose first.

Theres a slot that meshes with two tabs on the back of that aluminum nut..which will sometimes snap off ( like a shear pin does ) before the crank bolt strips. I sure hope thats the case for you!!!

[m.qualls89]

Ok ill post some tomorrow. I'm in the house for the night I got frustrated lol.

[chuck hahn]

First thing you need to do is remove the cam chain tensioner, then remove the cam chain from the cam sprockets. Next, take a shoe lace or buggee cord and go thru the chain and tie it off up to the frame so you dont drop in down inside the engine.

Then remove the cam caps...notice each one is lettered. They go back in the exact same spots.AtoA..B to B etc etc. Loosen the bolts evenly to avoid them jammimg up.

Remove the cams so all the valves will be up as far as they can. Do all this so when your working on that crank bolt you are not smashing against the valves any more than what has already been done.

NOW..you can go down to the 12MM steel bolt and try to take it out of the crank..its lefty loosey righty tighty. use a 6PT wrench or socket..12PT seems to not grip as well as 6PTers do. A few good smacks with an impact driever will aid in getting it loose. I am willing to bet the tabs on the back of the 19MM aluminum cap is what has given way..least I hope so.