Author Topic: Installing Cam Head Issues?  (Read 1418 times)

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Offline Hal9000

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Installing Cam Head Issues?
« on: April 20, 2015, 09:43:00 PM »
I'm new so please let me know if I am in the wrong section.
I am reconditioning a 1978 cb550 and I took the head off today to replace the bolts.
When re-installing the head I did not know to use the elastic bands on the tappets or to screw them out all the way.
I did make sure they were on top of the valves when installing by just pulling them up by hand but there was some resistance when I was bolting the head back down. I just attributed this to the one or two that was tight on the cam rotation.

My question is is this OK as long as the tappets were on top correctly?
is the resistance I felt when bolting down the top normal and OK?
I took the points cover off and spun it a few times and everything seems to spin ok but there is no oil in so I don't want to spin too much.
Any input is appreciated.

Offline calj737

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Re: Installing Cam Head Issues?
« Reply #1 on: April 21, 2015, 04:44:47 AM »
So you made a rookie mistake, but probably were spared damaging the engine. It's not guaranteed that you will bend a valve without releasing the tension, it's that you might.

There should be no danger in spinning the motor a few cycles to verify proper movement while rebuilding. If you're concerned, spray a bit of oil into the cylinder thru the spark plug hole. These are dry sump motors to begin with, so residue from previous running is all that coats the motor during start up. The combination of "dry" and "heat" is what does the greatest damage to the engine.

Just be certain you oriented the cam properly and your timing is set. Then button up and ride!
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Offline iron_worker

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Re: Installing Cam Head Issues?
« Reply #2 on: April 21, 2015, 08:13:07 AM »
I think even with the adjusters backed out all the way, the rockers will still contact the valve tips before the bolts are fully down. So, this resistance you felt might have just been the spring pressure / a valve opening as you seated the rocker cover. I would rotate the engine over slowly by hang and keep an eye on the rockers and that everything seems to be moving freely.

IW

Offline Hal9000

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Re: Installing Cam Head Issues?
« Reply #3 on: April 21, 2015, 09:46:08 AM »
Phew, Thanks very much for your replies,
So just to make sure I don't make any further rookie mistakes is there a place to find info on how to orient the cam correctly and do the timing? I don't have a book for this bike unfortunately...

Offline calj737

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Re: Installing Cam Head Issues?
« Reply #4 on: April 21, 2015, 12:46:12 PM »
The manuals are available to be downloaded here freely. The cam has a notch in the sprocket that needs to be oriented to 3:00 or 9:00 when the #1 cylinder is at TDC.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline strynboen

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Re: Installing Cam Head Issues?
« Reply #5 on: April 21, 2015, 01:04:07 PM »
 :)..klick on Photo to get it bigger..
yes..3 o klock...
« Last Edit: April 21, 2015, 01:05:56 PM by strynboen »
i kan not speak english/but trying!!
http://forums.sohc4.net/index.php?topic=60973.0
http://forums.sohc4.net/index.php?topic=144758.0
i hate all this v-w.... vords

Offline MRieck

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Re: Installing Cam Head Issues?
« Reply #6 on: April 21, 2015, 02:00:29 PM »
I think even with the adjusters backed out all the way, the rockers will still contact the valve tips before the bolts are fully down. So, this resistance you felt might have just been the spring pressure / a valve opening as you seated the rocker cover. I would rotate the engine over slowly by hang and keep an eye on the rockers and that everything seems to be moving freely.

IW
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