KNOCK after timing "76 GL1000


Information and questions on GL1000 Goldwings (1975-1979)
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veteranschoolboy
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Motorcycle: 1976 GL1000

KNOCK after timing "76 GL1000

Postby veteranschoolboy » Tue Oct 21, 2014 8:35 pm



I just spent the last two hours setting the timing on my recently purchased "76 GL1000 :? I started it and it would not stay running and I have a loud knock coming from what sounds like number 4 cylinder. Yesterday I took the timing covers off and found the idlers were not touching the belts, I set them to touch the belts. It ran much better after setting the idler pulleys. The belts appeared to be sound, however I plan on changing them out the first of the month. I have not synced the carbs yet. They need to be synced. Did I just shell the motor?



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virgilmobile
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Re: KNOCK after timing "76 GL1000

Postby virgilmobile » Wed Oct 22, 2014 7:25 am

Give it another shot before you dump it...
There is a procedure to follow before you crank it back up.

1st. revisit the timing belts...hand turn the engine and verify that the timing marks line up on each cam with the flywheel on the "T1" mark...Do this with all 4 plugs out...It should turn free with no unusual noises.

2nd..set the valve clearance "by the book"...Tolerances are very close.viewtopic.php?f=13&t=2229

3rd..If possible,now is a good time to check compression...Crank wide open throttle,kill switch "off",expect above 130psi per cylinder and no more than 5psi difference between any of them.

4th..The ignition timing....setting points on the 1000 can be set in a hour or so just using a test lamp.
Read about the "split the difference" method..This really does make a difference..It not only gets the timing exact but also ensures the same dwell angle.http://www.randakksblog.com/ignition-qu ... technique/

5th..Syncing the carbs...Another project that takes a hour or so IF you have the gauges or some such equipment..It's necessary that they pull the same vacuum with the engine at 1000 rpm...right where you normally hear the rattling of the primary chain.viewtopic.php?f=11&t=81

veteranschoolboy
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Joined: Mon Sep 01, 2014 6:10 pm
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Re: KNOCK after timing "76 GL1000

Postby veteranschoolboy » Wed Oct 22, 2014 1:05 pm

I have pulled the timing covers off both sides are on the mark, The crank shaft mark is not readable. I will use a magnifying glass to see if its there, It was popping at low RPM's, That's why I timed it, 1 & 2 were Advanced about 15 degrees 3 & 4 were about 10 degrees advanced. I need to sync the carbs, if I get it to run. Will the vacuum level cause it not to run, if so is there a starting point the adjustment screws should be set. I am off to see if the flywheel is on the T1 mark.

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virgilmobile
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Re: KNOCK after timing "76 GL1000

Postby virgilmobile » Wed Oct 22, 2014 1:46 pm

The timing..even if you get it exact,you should go back and check the point gap.Usually they will be different.This causes the change in dwell angle.
Whatever they are,find the midpoint and readjust.
Both points really need to open at the correct time AND the same ammount to get the spark just right.
The popping..was it in the exhaust or intake?

veteranschoolboy
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Re: KNOCK after timing "76 GL1000

Postby veteranschoolboy » Wed Oct 22, 2014 2:05 pm

I see the timing mark on the crank shaft pulley, it is right on the mark on the case, as are the two camshaft pulleys, the fly wheel is on the F mark on the T1 , So F mark is lined up with the timing belt marks. I just did the compression test all 4 have 130-132 psi. I spun the engine over for about 10 seconds, there was no knocking, just the sweet sound of a spinning motor. In order to see the crank shaft timing mark I had to pull the radiator. My only question is there a specific setting the vacuum screws should be set for a starting point. The popping is in the exhaust.

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virgilmobile
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84 GL 1200 I

Re: KNOCK after timing "76 GL1000

Postby virgilmobile » Wed Oct 22, 2014 4:10 pm

Careful now.
The "F" mark it where the cylinder fires at.The "T1" mark it top dead center.This is where the cam must line up with the marks.
The bike will run if the timing belt is off one tooth,just not very well.
The "F" mark is 10* before TDC.
The carbs..if I had to pre-set them without pulling them.
Adjust the main idle screw out a few turns,till to no longer touches.
Move to the center screw,between the carbs on the right side.
As you turn it,that throttle plate closes.You can push on it and see when it no longer moves.Slowly turn it back until you either see the arm move or hear the throttle valve pop loose.Stop there.
Move to the left and do the same for the rear then front.
You are trying to get the linkage to open the throttle plates from fully closed at the same time.
Bump up the idle screw and sync it.
Once you play with the screws a few times,you'll see how they operate each carb.
The sync is painless after that.Balance the right pair first,then the left pair and finally left to right.
Don't jump around.its a specific order.
All this and keeping the rpm near 1000 too.
Popping Is unburnt fuel igniting in the exhaust.Dont concern yourself till the rest is done.

veteranschoolboy
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Re: KNOCK after timing "76 GL1000

Postby veteranschoolboy » Fri Oct 24, 2014 12:34 pm

I sure appreciate your help with this, well I have another issue now, At the points there is no power on 1 & 2. 3 & 4 work fine. Went up by the coils and tested for power, with the blue there is power when 3 & 4 points are open, no power when the points are closed, On the yellow the is power when the points are open and no power when the points are closed. I ran this test two times, retesting the points still no power on 1 & 2 ., How is it there is power at the coils with the points open but at the points there is no power when the points open.

Let me be clear that, at the points I have the clip on the band on the points and ground the pointer on the engine, when testing at the coils I ground the clip to a bolt and slide the pointer into the wire connectors. Any idea whats going on with the wiring.

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virgilmobile
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84 GL 1200 I

Re: KNOCK after timing "76 GL1000

Postby virgilmobile » Fri Oct 24, 2014 4:15 pm

Split the system...the points have a short harness.Unplug both wires.turn on the key.both should have volts on the harness side.
With your ohm meter or test light,measure each wire going to the points.As you turn the engine,the meter should go to no continuity as each point opens.Every 180* and show a short with the points closed.
You can use the test light probe also.Connect one lead to one set of points(unhooked from the harness) and the other end to the battery positive.Same...turn the engine and watch for the light at each "F1" mark.You don't need the key to be on.

veteranschoolboy
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Joined: Mon Sep 01, 2014 6:10 pm
Location: Watertown, MN
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Re: KNOCK after timing "76 GL1000

Postby veteranschoolboy » Fri Oct 24, 2014 10:16 pm

I can't thank you enough, she is up and running, it was 70 degrees up here today, I took her out for about a half an hour and she purred like a kitten. I still have to sync the carbs, you explanation on adjusting the vacuum sets was spot on. Every time I take her out I will be thinking about how you helped me. Thank you, very much, Veteranschoolboy signing off.

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virgilmobile
Posts: 7663
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: KNOCK after timing "76 GL1000

Postby virgilmobile » Sat Oct 25, 2014 9:00 am

Yeaaaa.
Dontja love it when a plan comes together better than you expect?




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