Author |
Message |
Deanh8
| Posted on Friday, November 14, 2014 - 02:34 pm: |
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Its been a long week, I cant figure out why this is jumping around like this. Anything I am missing here? http://youtu.be/BXgGR3V-Z-I |
Nuts4mc
| Posted on Friday, November 14, 2014 - 03:18 pm: |
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imo the "jumping" is caused by the cam's interaction with the valve springs...the chain is too loose...as the cam reaches a "peak" the cam jumps ahead to take up the slack "powered" by the valve spring tension. I would check the tensioner (it's easy to get to ...back side of the cylinder retained in place by a "plug"....but you need a modified hex key (you'll have to cut one down (1"? long) and use a box wrench on the hex "stub" to unscrew it...mine was very tight), the parts book calls it a tensioner assembly but if I remember correctly it's a spring loaded "cup" pushing against the cam chain "slipper"...if the cup has seized in the bore...or someone forgot to put the spring back in (Doh!)...the cam chain slipper is not doing it's job...Note I would not turn over the engine too many times with a loose cam chain...you could lose the "timing"...suggest you put a dowel/or straw down the spark plug hole rotate the engine to find TDC and lock the rear cylinder while you investigate the tensioner...hope this helps |
Deanh8
| Posted on Friday, November 14, 2014 - 03:24 pm: |
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Ive got locking tools to find TDC. I replaced the cam tensioner with another and same problem. I was also thinking stretched chain, only the rear though? |
Nuts4mc
| Posted on Friday, November 14, 2014 - 03:34 pm: |
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are you turning the engine in the correct direction?...back in the day... we used to set our manual cam chain tensioners by rotating the engine in the opposite direction from normal running direction causing slack on the pulling side of the chain...we would then push the tensioner into the slipper and lock it in place taking up the slack...?? |
Deanh8
| Posted on Sunday, November 16, 2014 - 08:55 pm: |
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I was spinning it like that to exaggerate the problem for the video. Cam chain is stretched, tensioner is maxing out and chain is still loose. On further inspection the chains actually touch each other at one point from being stretched so much. (Message edited by deanh8 on November 16, 2014) |
Nuts4mc
| Posted on Monday, November 17, 2014 - 01:00 pm: |
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good to hear you got it worked out! |
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