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Post by renagade281 on Nov 11, 2015 14:47:08 GMT -5
 Ok the timing is correct. The mark is lined up with the "T". When I try to start it, it makes a loud clacking noise. I think this piece (the one I'm pointing to) is not in the right position ...  Here's a short video of what it's doing... youtu.be/s8gvZt8DPygAny info you need other than what I have provided let me know. I'm stumped on this one Edit: when I adjust the top valve and try to start it. I can't take the cover off and out it on TDC and its loose just like at the end up the video like its not getting pushed back up properly |
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Post by 90GTVert on Nov 11, 2015 15:52:22 GMT -5
Set it to TDC with the cam marks aligned. Rotate the engine slowly by hand. If you find that there's more clearance anywhere but at TDC or notice that a valve is in motion at TDC, there is a timing issue. You should only feel slack when the cam is on the base circle. Otherwise it should feel like 0 lash, no slack.
If the timing is alright, perhaps there is an issue with a valve.
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Post by renagade281 on Nov 11, 2015 18:41:54 GMT -5
i think its an issue with the valve.. he put an 80cc BBK in it but used the stock valves,,,is that normal to do?
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Post by renagade281 on Nov 11, 2015 19:00:58 GMT -5
Notice that the intake valve does not move at all when the engine is turned.. The exhaust valve does but the intake valve doesn't.... youtu.be/EsXYysEV4Kk |
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Post by strgazr27 on Nov 11, 2015 19:52:56 GMT -5
Are the dots on the cam gear parallel to the top of the head? Maybe it's the angle of that picture but it looks like it's off a tooth. If they aren't than its not timed correctly.
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Post by strgazr27 on Nov 11, 2015 19:55:12 GMT -5
Just watched the video. Is the valve adjustment nut too far backed out? If it is that could be the issue.
Is the valve stuck open and the rocker is resting on it all the time?
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Post by strgazr27 on Nov 11, 2015 19:57:11 GMT -5
i think its an issue with the valve.. he put an 80cc BBK in it but used the stock valves,,,is that normal to do? By stock valves you mean original head with an 80cc jug/cylinder? |
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Post by renagade281 on Nov 11, 2015 21:21:31 GMT -5
Just watched the video. Is the valve adjustment nut too far backed out? If it is that could be the issue. Is the valve stuck open and the rocker is resting on it all the time? No the valve gets stuck when its pushed in. I will post a short clip tomorrow of what I'm talking about. |
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Post by strgazr27 on Nov 11, 2015 21:40:44 GMT -5
If the valve gets stuck it could be a bent valve stem. That's why I asked if it was a stock head with a 50mm cylinder.
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Post by 90GTVert on Nov 12, 2015 8:55:24 GMT -5
It's time to remove the head and look at it. If this is the same one from another post, you might as well plan on replacing the head for that issue at least.
It's not uncommon for somoene to use a stock head with a 47mm bore. Less common with a 50mm plus bore. Regardless of bore size, the valve should only bend if there's contact with the piston which could be a timing or other clearance related issue. You would need to verify that TDC is really TDC when the head is off. Some of these engines are not machined right and TDC on the flywheel does not match actual TDC. That will change the timing and can lead to piston and valve contact in addition to poor performance.
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Post by renagade281 on Nov 12, 2015 9:23:24 GMT -5
youtu.be/wqafeupiiGUThat is a video. I have done some research and come up with a possible "valve seat drop" the valve goes down but will not come back up In the video u will notice the first 2 times I rotate it the valve goes in and gets stuck for a second then pops back out. The 3rd time it goes in and doesn't come back up at all
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Post by Fox on Nov 12, 2015 9:44:19 GMT -5
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Post by strgazr27 on Nov 12, 2015 11:11:48 GMT -5
Bent valve. No doubt about it. I wouldn't even bother pulling it to check. Easier to just buy a new head.
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