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Post by scooterfan86 on Nov 8, 2014 22:04:47 GMT -6
So I've taken the engine down to the head and replaced all the gaskets along with the valves and valve springs. A broken spring on the exhaust valve turned out to be the issue that needed dealing with. I am having an issue with the intake valve not opening up properly though. It is a new valve and springs up and down just fine with hand pressure, but when I close everything up and turn the flywheel by hand it rigidly binds on pushing the intake valve every time. There's no give at all, and no increase in pressure beforehand on the flywheel. I feel like I run into a piece of steel that won't budge. Having opened and closed and reopened things I've come to be sure that it is indeed the intake valve side of things not working right, but there doesn't appear to be anything rocker at all with the rocker arms or anything else. I put some white paint on the rocker arm pad and sure enough it lands spot on top of the intake valve.
And again, the valve moves freely just as the exhaust valve does with heavy hand pressure. It feels right, and everything looks right, so I'm stumped at what to do next. Any suggestions?
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Post by scooterfan86 on Nov 8, 2014 22:05:06 GMT -6
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Post by scooterfan86 on Nov 8, 2014 22:10:47 GMT -6
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Post by JR on Nov 8, 2014 22:15:41 GMT -6
 Your picture is not clear of the top of the valve? For some reason it looks like the top of the valve stem is damaged?
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Post by scooterfan86 on Nov 8, 2014 22:24:07 GMT -6
Okay I'm an idiot lol... if I put my finger over the spark plug hole I can get the exact same effect with everything locking up right when the intake valve is at its peak. The compression and expansion seem to be the culprit.. while only one of them actually locks everything up.
Should I be concerned about this as I rebuild everything? Am I doing something wrong with the rebuild or will it just work itself out as I put the air box back on etc? I'm still not sure why this is happening, but it doesn't actually seem to be the valve. Is this vapor lock?
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Post by scooterfan86 on Nov 8, 2014 22:34:02 GMT -6
And ps this could be perfectly normal for an engine.. if it is please let me know. I was able to hand crank the flywheel before though without the engine compression stopping me and don't want to try starting up my engine if something sounds like it's wrong.
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Post by alleyoop on Nov 8, 2014 22:41:56 GMT -6
To find out if it is just compression, put the valve Assembly on and LEAVE the spark plug out and see if you can turn it over. It should turn over easy through the compression stroke. If it still binds then something is not right. CHECK your timing, Bring the Piston up to top dead center CHECK the timing mark on the Flywheel and Check the Alignment of the CAM. At this point Both Valves shout be closed, Cam Lobes to the side or down and away from the rockers if they were there.
Alleyoop
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Post by scooterfan86 on Nov 8, 2014 23:26:19 GMT -6
It happens even without pressure, darn it. I'll check out the timing to see if this could be the issue.
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Post by alleyoop on Nov 8, 2014 23:36:11 GMT -6
Then something is binding DO NOT START it until you can turn the motor over by hand and then on the compression stroke you can feel it and with your hand you should be able to turn it through the compression stroke and then it should be easy as pie until the next compression stroke.
Alleyoop
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Post by alleyoop on Nov 8, 2014 23:45:12 GMT -6
Make sure the adjusters are loose and that you can move them by hand back and forth.
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Post by scooterfan86 on Nov 8, 2014 23:49:35 GMT -6
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Post by scooterfan86 on Nov 8, 2014 23:51:43 GMT -6
I can't find any T mark with a mirror, flashlight, and turning the flywheel by hand. I'll see if I can get a friend to help me look tomorrow. But if this T isn't in the right place, could everything bind up like what's happening to me?
Is there another way to get the timing right if there is no T ?
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Post by alleyoop on Nov 9, 2014 0:01:43 GMT -6
There is a "T" it is very faint and hard to see. Many have a hard time spotting it but it is there. A tip to know when it is CLOSE is stick a screwdriver in the spark plug hole and watch it when the screwdriver gets pushed out then look for the "T".
Now you could be 180 degrees at this point if you cannot see it so rotate it again and when the screwdriver comes out again look for the "T".
** VERY IMPORTANT ** make sure the valve adjusters are loose so when you put the valve cover on there is no pressure on the valve stems.
Alleyoop
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Post by scooterfan86 on Nov 9, 2014 0:13:49 GMT -6
Found a capital F haha, I'm presuming that's got to be it. I'll at least give reinstalling the chain and camshaft in this position and see if it works.
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Post by alleyoop on Nov 9, 2014 0:22:52 GMT -6
There SHOULD BE A "T" before the "F" like this but that is at least close. So at this point stick a screwdriver down the plug hole and move it a little so you can tell when the screwdriver is out the farthest and that should be your TOP DEAD CENTER point and remember the cam lobes should NOT be anywhere near the rockers flat part. The Flat parts of the rockers should be OFF the HIGH LOBES of the CAM. Alleyoop  |
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..BAD TO THE BONE..
