GL1100 Timing belt change gone wrong. Please advise.

1847 Views 10 Replies 8 Participants Last post by chilidawg, Feb 9, 2013

colonel-saunders

Discussion Starter · Feb 9, 2013

Hi all,

I was about to change the timing belts on my 83 GL1100, and had dropped the radiator, and taken off the covers, when some unexpected "help" arrived on scene. At this point I had NOT turned the engine to TD1. It was just as it sat from the last ride.

My "help" decided to released the tensioner bolts and slipped off the belts. Then they took out the spark plugs, and gave BOTH cams a spin to "clear em out"

All this before I could get back out there to stop it. :wtf:

My question is this: What do I do now? can I just rotate the crankshaft to TD1, and then manually position the cams to the correct indexing marks?

In the back of my head, I think that the valves would have a 50/50 chance of being in the correct "position" with TD1 in the window, the CRANKshaft lined up with its index mark, and the CAMshaft manually positioned to their respective index marks.

I'm all ears gentlemen.

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CaptainMidnight85

· #2 · Feb 9, 2013

Set the engine to T1 and index the cams.
Turn it over afterward by hand to make sure all is good.
So yes, you're on the right track.
Odd that he was spinning both cams around without turning the crank at least some...
Anyway, T1 the crank and index the cams.

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bgriffey

· #3 · Feb 9, 2013

Well I would think that if you put the timing marks were they should be, then all will be good! Let me know how this turns out!

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colonel-saunders

Discussion Starter · #4 · Feb 9, 2013

This is what I will try. thank you.

I have also read that a straight line can be drawn between the left index mark, left cam pulley bolt, crankshaft bolt, right cam pulley bolt, and right index mark.

Is this accurate? I would like an additional check of the 'trueness' of the index marks, and I have a big straight edge. Also white thread pulled tight might work to show a straight line.....

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rayworx

· #5 · Feb 9, 2013

Let me get this straight…. you 'helper' pulled the belts without knowing the position of the crank/pistons NOR the positions of the cams.
He (the helper) then spun the cams irregardless of the position of the crank/pistons.

Right now it's possible that the helper could have spun the cams and forced valves into 1 or more pistons. It's also possible that no damage occurred at all…. but you don't know that.

Given that you don't want to do any more damage (if any has been already done) I would try this:
remove the valve covers on both sides. Without moving the crankshaft or the cams…. loosen the valve adjuster lock nuts and UNSCREW the adjusters at least 2 full turns. This will back off the valves so they won't be so inclined to contact the pistons when you turn over the crankshaft. Note that some valve adjusters will be very snug and 1 or 2 will be loose. That's normal but count the turns anyway.
Now… turn the crank to the T1 position. Then turn the cams so they are properly aligned to the timing marks and both cam sprockets have the UP in the up position. Now install the new belts and proceed with a valve clearance adjustment.
This way you should be safe and save any potential valve/piston damage.

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littlebeaver

· #6 · Feb 9, 2013

I bet you were a little upset, scared to death and very concerned all at the same time...Did you smack your helper...:ROFL: I would have smacked him at least once for that..

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sccaz

· #7 · Feb 9, 2013

Since he turned the pulleys by hand, there should be absolutely no issue with damaged goods. As long as all timing marks are set where they need to be, your'e good to go. Once you get it running, give him a Gibbs backhead slap, and say "dont touch ever again" lol

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rayworx

· #8 · Feb 9, 2013

sccaz said:
Since he turned the pulleys by hand, there should be absolutely no issue with damaged goods. As long as all timing marks are set where they need to be, your'e good to go. Once you get it running, give him a Gibbs backhead slap, and say "dont touch ever again" lol

I wouldn't count on that. I had a guy bring in is wing in his truck saying he could only turn the engine over (by hand) so far and then he felt resistance. He said he tried turning it over several times and each time it would get hung up with resistance… finally he got it to turn all the way through.

He'd put new belts on, got the timing off and was hitting a valve every time he 'felt resistance'. Finally, when he got the valve bent it would go through a full 360 degree rotation. He felt really proud when get got the engine to go through 720 degree rotation.
I never count on anything... when it comes to valve damage. What's the other saying??? Better safe than sorry???

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chilidawg

· #9 · Feb 9, 2013

As above, but as long as your belt wheels have the word "UP" vertical, or as vertical as they can get, with the T1 timing mark in the right position, slap those belts on and run that thing!

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Steveb123

· #10 · Feb 9, 2013

rayworx said:
I wouldn't count on that. I had a guy bring in is wing in his truck saying he could only turn the engine over (by hand) so far and then he felt resistance. He said he tried turning it over several times and each time it would get hung up with resistance… finally he got it to turn all the way through.

He'd put new belts on,

The OP had no belt installed at the time of cam turning. If the valve hit the piston top, it will simply push it down the bore slightly.
No harm done, unless the piston is siezed in the bore!

Cheers.

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chilidawg

· #11 · Feb 9, 2013

THE "UP" marks on the timing wheels are your friend, do not ignore them!

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