Timing Belt Questions (about T1 mark)

Erdoc48

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I have the 94 all torn down, the hoses are out and the radiator is out as well. I have the timing belt fully exposed and I'm just awaiting my new Gates belt from an Amazon vendor. I have rotated the crank such that both cam marks line up perfectly- here's the issue...the T1 mark does not line up with the arrowhead nor does the punch mark line up with the case T1 indicator (with the cam marks in the proper position, the T1 mark and punch mark is in advance of the arrow marker by ~ 1/2 inch). I have loosened nothing so this is how the belt was on the bike and it runs flawlessly.

Do I just leave the cam marks where they are and the T1 / punch mark where they are, put the new belt on and be done with it? I'm kind of puzzled as I don't believe the prior owners (2 of them) ever changed the belt. The belt does look to be in excellent shape but I opened up everything to change it out as long as I had gone as far as I did.

I turned the crank bolt several times to check the index points and I get the same results each time.

Any help is greatly appreciated.
 
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First thing - are you sure the number 1 cylinder is on TDC of its compression stroke when you are checking the timing marks?
 
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Can't say I had any such issue when I changed my belt earlier in the year. Are you following this diagram?

IIRC it is not so easy to get the T1 mark aligned clearly as you will be looking in from the side (unless you take the front wheel/forks out!).
 
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Erdoc48

Erdoc48

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That’s exactly the diagram I was using (from the shop manual)- I’ve turned the crank bolt clockwise numerous times thinking it may take some turning to get it all lined up but I get a consistent result in that if the T1/ punch mark is set right, the cam marks are off and if the cam marks are set exactly, the crank sprocket marks are off (as I indicated in the first post, forward of the mark by about 3/4”). I’m not sure why this is and as I said, I didn’t loosen anything
 
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Erdoc48

Erdoc48

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OK, here’s what I found...if I take out spark plug #1 (seated on bike, right front cylinder) and set the mark at TDC, it’s not at TDC. If I line up the 2 cam marks properly and the T1/ punch mark is a little past the proper marks as above (like 3/4” as previously mentioned), cyl #1 is at TDC. This is VERY strange- I wonder if it left the factory this way, which would not be like Honda at all!
 
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That’s exactly the diagram I was using (from the shop manual)- I’ve turned the crank bolt clockwise numerous times thinking it may take some turning to get it all lined up but I get a consistent result in that if the T1/ punch mark is set right, the cam marks are off and if the cam marks are set exactly, the crank sprocket marks are off (as I indicated in the first post, forward of the mark by about 3/4”). I’m not sure why this is and as I said, I didn’t loosen anything
If someone removed the cams to do a valve adjust, since they're gear driven the cams could have been put back in one tooth off.

So are you saying the crank and cam sprockets align properly, just that the cams themselves aren't aligned? If so, then the cam removal theory would probably explain it. If the crank and cam sprockets don't align, then the belt may have been replaced before, as removing the cams wouldn't have any effect on that alignment.
 
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You should have all the plugs out to make turning the engine over easier and to be more accurate on getting the marks aligned. It doesn't take much off TDC for those marks to be wrong.

Do you have the valve covers off? Even just the right one off would help you determine TDC of the compression stroke for #1. You can't be sure you are on the compression stroke unless you can see the movement of the valves. When you see the #1 intake valves closing, you will be on the compression stroke and the marks should be coming up to proper alignment, once the piston hits TDC.
 
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I'd be wary at this point of drawing too many conclusions; probably best to reset all parts to their correct alignment then turn the engine over by hand a few times to ensure no parts are clashing.

Given the apparent offset between the crank timing mark and true TDC, one could almost suspect that the drive pulley has shifted on the crank end, but that should not be possible as their is a Woodruff key pegging them together. However I don't know that the T1 mark should correspond exactly with TDC.

Certainly all the pulley marks (crank and cam idlers) should align unless the belt is stretched or they are off by whole teeth due to misalignment. And the cams will definitely align exactly to the idler pulleys unless they too are offset by whole teeth.
 
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Erdoc48

Erdoc48

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OK, here’s what I found. I think my crank is off because TDC on #1 is not in sync with the T1/ punch mark- to get to TDC, I have to advance the crank just a little bit - at that setting, the cam marks are spot on but the T1/ punch is a little more clockwise than it should be- I’m not sure if anyone was this deep into the bike before as I’m not the first owner
 
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Erdoc48

Erdoc48

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I'd be wary at this point of drawing too many conclusions; probably best to reset all parts to their correct alignment then turn the engine over by hand a few times to ensure no parts are clashing.

Given the apparent offset between the crank timing mark and true TDC, one could almost suspect that the drive pulley has shifted on the crank end, but that should not be possible as their is a Woodruff key pegging them together. However I don't know that the T1 mark should correspond exactly with TDC.

Certainly all the pulley marks (crank and cam idlers) should align unless the belt is stretched or they are off by whole teeth due to misalignment. And the cams will definitely align exactly to the idler pulleys unless they too are offset by whole teeth.
I spoke with my brother and he said this as well- take the belt off with the crank mark at the right setting and just advance the cams to their proper setting. It’s really strange since it runs so well despite the valve timing seemingly being off. He said I could take the crank bolt off as well to make sure the crank key isn’t sheared
 
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Erdoc48

Erdoc48

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You should have all the plugs out to make turning the engine over easier and to be more accurate on getting the marks aligned. It doesn't take much off TDC for those marks to be wrong.

Do you have the valve covers off? Even just the right one off would help you determine TDC of the compression stroke for #1. You can't be sure you are on the compression stroke unless you can see the movement of the valves. When you see the #1 intake valves closing, you will be on the compression stroke and the marks should be coming up to proper alignment, once the piston hits TDC.
With the right valve cover off, I set the marks of the cam as if for TDC, and the punch mark is still off (further clockwise by ~ 20 degrees or so). I assume what would be proper is set the punch mark, then with the belt off, adjust the cams to make the marks line up, then reinstall the belt. I would assume someone has been in there before as the belt looks as new (green HONDA with the part number), but who knows?
 
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He said I could take the crank bolt off as well to make sure the crank key isn't sheared
Once I replaced the timing belt on an 2.5 L Izusu Trooper engine in which the crank pulley had slipped; the timing mark is on the groove for the pulley and the hub is keyed to the crankshaft, but the two are connected by a rubber torsional damper. I determined TDC of the #1 cylinder by using a dowel stuck in the spark plug hole to feel the piston come to the top of the compression stroke. If you use a closed end wrench on the the crank bolt and move the crank back and forth slightly, you should be able to determine TDC within a few degrees. I set the belt to the camshaft index which was still correct and made a new mark on the crank pulley. Also remember that the camshafts move 1/2 revolution for each revolution of the crank.
 
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Can't say I had any such issue when I changed my belt earlier in the year. Are you following this diagram?

IIRC it is not so easy to get the T1 mark aligned clearly as you will be looking in from the side (unless you take the front wheel/forks out!).
I changed my belt right after I got my new 1991 home. On disassembly, the old belt aligned this way after I rotated the crank to align the T1 and dimple. Cam marks were right on as well. Other bikes I have worked on were not properly aligned at disassembly. I just fixed that with the new installation. The markings are there for a purpose.
 
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Erdoc48

Erdoc48

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I just figured I would update here- this AM, I tried to get the crank bolt off to make sure everything else underneath was OK (no sheared Woodruff key etc.)- even though the torque spec is 65 NM, that just won’t budge. Anyway, since my 2 cam marks are spot on and #1 piston is at TDC (I read it’s the right bank of cylinders in the front), I made a new mark on the case pointing to the punch mark and used a gold marker to accentuate the punch as well. I’m waiting for the belt in the mail today. I’ll post here once I’m done. I can only assume one of two things now:

-Bike was like this from the factory (which should be unlikely, but nothing is impossible), or
-Someone has been in there before and possibly messed something up (but again, this would be difficult to mess up with the cam key in there- I’m just not certain).

Thanks for you help thus far!
 
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I just figured I would update here- this AM, I tried to get the crank bolt off to make sure everything else underneath was OK (no sheared Woodruff key etc.)- even though the torque spec is 65 NM, that just won’t budge. Anyway, since my 2 cam marks are spot on and #1 piston is at TDC (I read it’s the right bank of cylinders in the front), I made a new mark on the case pointing to the punch mark and used a gold marker to accentuate the punch as well.
wow, that is weird, very interesting. Could you clear up one question for me please.

When you say "my 2 cam marks are spot on" its not clear if you're talking about the two cam sprocket alignment marks, the marks on the two cams, or both?

I think you're saying that with #1 TDC verified by piston position, both cam sprocket marks align, AND both cam marks align, just the crankshaft punch mark is off, right?
 
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Erdoc48

Erdoc48

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Sprocket alignment marks on both cams are perfect and the punch mark is at about 4 o’clock if you can imagine the proper ‘arrow’ on the case is at about 3 o’clock- I agree, very strange, and no idea why this is the case. What I did is make a sharpie mark at TDC so the punch and new indicator mark on the case meet up (my new ‘4 o’clock mark)- it took a while to get both cam alignment marks to be on the money with the belt on (so took it off one cam, adjusted same, then put the belt back on, then I had to go to the other cam and do the same. Now everything is spot on, engine rotates freely when turning the crank bolt, and after torquing the left cam bolt and tensioner, all is well. Now it’s just a matter of reassembly.

Thanks for the help everyone. The belt and cams are in the same position as before I started (so when the bike ran perfectly), so I fully expect it to start and run properly.

‘I think you're saying that with #1 TDC verified by piston position, both cam sprocket marks align, AND both cam marks align, just the crankshaft punch mark is off, right?’

^^ This, exactly. Very strange unless mother Honda installed a mismanufactured part, which I would think is very unlikely but not impossible.


Lastly, the old belt as others have said, appears in very good condition- no cracks and you can still see Honda in green as well as the part number 14401-MT3-004. I used a Gates T325
 
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What you are describing is exactly what you find on an engine with a stretched timing CHAIN. On some of the old Hondas the points lobe ran off the end of a cam, timing was taken off crank markings. So as timing chain stretched with age your timing with ignition was off also. I am new to ST1100, and have heard 90,000 mile timing belts look new. I wonder if they look new but stretch enough to create your problem of either crank marks aligning but not cams or vice versa. If it ran well, think I would align per service manual and follow all instructions when replacing the timing belt. Have noticed the tension spring seems much stronger then on the older Goldwings which I do have a bit of experience on. I'm betting your problem will go away when new timing belt is installed. Looking forward to your completing your project. Waiting for one more part to arrive before I change out my timing belt also. Good Luck
 
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