HELP - Bad knocking after head gasket fix


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matsonian
Posts: 3
Joined: Sat Jun 11, 2011 8:41 pm
Location: Sacramento, CA
Motorcycle: 1979 GL1000 GoldWing

HELP - Bad knocking after head gasket fix

Post by matsonian »



So a few months ago my 79 GL1000 was smoking bad on the right side. I decided to check the head and replace the gaskets, etc.

After pulling the head I had a local shop clean it up and make sure there weren't any cracks. All tested good.

I just finished putting it back together and started it up - and now I hear this:

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I have not pulled it back apart yet.

Obviously that doesn't sound good. Sounds like the pistons are knocking.

What did I miss?


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ekvh
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Location: Grand Forks, ND
Motorcycle: 1977 gl1000

Re: HELP - Bad knocking after head gasket fix

Post by ekvh »

Timing marks on the belt pulleys line up as they should with T1? Some pulleys have two marks. If yours does, it's the one with the arrow beside it.
matsonian
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Joined: Sat Jun 11, 2011 8:41 pm
Location: Sacramento, CA
Motorcycle: 1979 GL1000 GoldWing

Re: HELP - Bad knocking after head gasket fix

Post by matsonian »

Could it just be the timing? I will check that.
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dingdong
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Re: HELP - Bad knocking after head gasket fix

Post by dingdong »

If you didn't get the timing belt installed correctly you have bent the valves and possibly damaged a piston on that side. I wouldn't run the engine until problem is found.
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ekvh
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Re: HELP - Bad knocking after head gasket fix

Post by ekvh »

Remove the valve cover and look to see if all valve adjusters are in place and look to see if the valve keepers are all in place. (The two halves which are sandwiched around the valve) If they weren't fully seated, they can come flying out. It would cause quite a clatter. Look for other damage such as broken springs, broken cam carriers.

If that's all good and you did just one head it is trickier. The suggested way to be safe is rotate the crank ccw a bit to get the pistons down in the bores. If you don't keep track of which way it went then go the opposite way when you bring the pistons back to T1, you can be on the wrong one. But that should cause the knocking your vid shows. There's only one T1 but since cams move 1/2 speed, for each cam revolution there are two T1 events for each cam revolution.

Remove both belt covers and note whether the UP marks are in the same relative spots. If one is at 4 o'clock the other should be the same. If they are, bring them to T1 with both UP marks up and the pulley marks lined up with the marks on the covers.

See if your pulleys have these marks, or just one mark.


As mentioned it should be on the one with arrow.

If the pulleys don't appear to be in the same relative position, remove the right side belt before rotating. Loosen all valve adjusters on the right side all the way out. Note the position of T1 or T2 through the crank timing window. If right on T1 two cylinders are at TDC and your valves could contact them. So rotate the crank 1/4 turn to pull all pistons out of the way. If you feel contact, go the opposite way and remember which way you went. ( CW OR CCW)

Now your valves can move without contacting pistons. Rotate until at T1 and that the left pulley's UP mark is up. Rotate the right pulley to T1 using your hand. Make sure both UP marks are up and the pulley marks are correctly aligned with the marks on the covers. If not, adjust the belts until they are. Wiggle the valve adjusters on the left cam side. If only one wiggles, adjust the #3 intake valve on the right side. Next rotate the crank around to the next T1 event and set the remaining valves on the right side. If three valves wiggle when you test the left side, do the reverse: set 1intake and exhaust and 3 exhaust, the rotate and set the 3 intake valve.

You may have some damage. You'll have to investigate as above to see.
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Maz
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Re: HELP - Bad knocking after head gasket fix

Post by Maz »

Hopefully, that knocking is just because it is only running on one cylinder. These engines sound real bad when not running on all four and the less cylinders firing, the worse they sound. If your valve timing IS out, let's hope it's only one or two teeth off.
Maz
Ironically, Common Sense is the LEAST common of all senses!
matsonian
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Joined: Sat Jun 11, 2011 8:41 pm
Location: Sacramento, CA
Motorcycle: 1979 GL1000 GoldWing

Re: HELP - Bad knocking after head gasket fix

Post by matsonian »

Thank you - great feedback! I know what I am doing today. ;-)


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