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Need Saito 100 help!!!

Old 08-27-2014, 06:46 PM
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ro347
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Default Need Saito 100 help!!!

Im in need of help with my Saito 100. Recently I replaced gaskets and seals, and ever since I haven't been able to get it to run right. IF it wasnt one thing it was another. Once Ive ruled everything else out, Ive come to the conclusion I had a timing problem despite know how to set it during reassembly.

With that said, last night I took the engine apart ( which is when I realized timing issue) and saw this SEE PIC.... Looks like the valve hit the piston at some point. Everything looked ok otherwise, so I reassembled and tried to run. Seem to do ok put had a hard time with the high end needle and engine lost compression again.

So to my point - IS THERE ANYONE WILLING TO HELP ME GET THIS THING GOING AGAIN>>>> PLEASE!!!!!!!! Im just at a lost. Im guessing maybe replacing the valves (as one might possible be slightly bent) might help, but dont want to be throwing money into parts Im unsure I need.

Would appreciate if anyone could give me the rundown of what to look for and check.

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Old 08-27-2014, 08:43 PM
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JollyPopper
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That is a really interesting picture. I can't imagine a valve hitting the SIDE of a valve relief in the piston (those angled depressions are called valve reliefs). The valve should be opening and closing at the same angle as that valve relief and if the valve were ever to strike the piston, it should strike with the head of the valve flat in that relief. Notice your push rod tubes. They are at the same angle as the valves and the relief. It should not be possible for the edge of the valve to strike the side of the valve relief. If the valve made that mark, it would almost certainly be bent badly enough that the engine would not run. Since you have the engine this near disassembled, my advice would be to take that valve out of the head and roll it on a piece of glass. If it is bent, you will be able to see it. But if it is bent that badly, the engine should not run. As Yul Brenner said, this is a puzzlement.
Old 08-28-2014, 04:16 AM
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Thinking about that, the valve could hit there because as it moves toward closed it moves back away from the center of the piston. Bewing out of time could indeed allow it to hit there. I gotta go to the Dr. so I must run. To verify that the timing is correct pull the back plate and watch as the piston rises on the exhaust stroke, at TDC both valves should be open slightly, (overlap) byt the same amount.
Old 08-29-2014, 03:26 PM
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Hobbsy, I don't follow your logic here. The only thing that determines the path of that valve in opening and closing is the valve guide. Assuming the guide is in its proper place in the head and the valve is not bent, there should be no way for the edge of the valve to touch the side of that relief. Timing can't affect the path of the valve. If you rotated the crankshaft and held the piston at TDC manually, then removed the valve spring and keepers and manually moved the valve up and down, it should never touch the side of the relief where that mark is. At least that is how I see it. I could be wrong, but I can't visualize how a valve with a straight stem could strike the side of its relief. The valve head can't move laterally as it ascends and descends. Maybe I'm seeing the picture wrong.
Old 09-01-2014, 04:51 AM
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Sorry JP, I think you're seeing the picture mostly right. I need to re-think and maybe retract and then not say anything at all if I can't sort it out.
Old 09-02-2014, 05:31 AM
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The valves are at an angle, I can see it hitting there, did you set you align the pip marks on the timing gear properly, one tooth off is all takes.
Old 09-02-2014, 10:00 AM
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Yes, the valves are at an angle--exactly the same angle as the sides of their reliefs. No matter what the timing is, the path of the valves does not change. The only thing that can change the path of the valves is the valve guide. Without a bent valve stem or dislocated valve guide, the valve can NEVER hit the side of the relief. The valve head can never move laterally in its path up and down.
Old 09-02-2014, 11:43 AM
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I still think that the valve could hit there if it was not fully closed when the piston reached TDC.
Old 09-02-2014, 04:43 PM
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Did you check/adjust clearance for both valves?


Originally Posted by ro347
Im in need of help with my Saito 100. Recently I replaced gaskets and seals, and ever since I haven't been able to get it to run right. IF it wasnt one thing it was another. Once Ive ruled everything else out, Ive come to the conclusion I had a timing problem despite know how to set it during reassembly.

With that said, last night I took the engine apart ( which is when I realized timing issue) and saw this SEE PIC.... Looks like the valve hit the piston at some point. Everything looked ok otherwise, so I reassembled and tried to run. Seem to do ok put had a hard time with the high end needle and engine lost compression again.

So to my point - IS THERE ANYONE WILLING TO HELP ME GET THIS THING GOING AGAIN>>>> PLEASE!!!!!!!! Im just at a lost. Im guessing maybe replacing the valves (as one might possible be slightly bent) might help, but dont want to be throwing money into parts Im unsure I need.

Would appreciate if anyone could give me the rundown of what to look for and check.

Old 09-04-2014, 02:19 AM
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Rudolph Hart
 
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Originally Posted by ro347
Im in need of help with my Saito 100. Recently I replaced gaskets and seals, and ever since I haven't been able to get it to run right. IF it wasnt one thing it was another. Once Ive ruled everything else out, Ive come to the conclusion I had a timing problem despite know how to set it during reassembly.

With that said, last night I took the engine apart ( which is when I realized timing issue) and saw this SEE PIC.... Looks like the valve hit the piston at some point. Everything looked ok otherwise, so I reassembled and tried to run. Seem to do ok put had a hard time with the high end needle and engine lost compression again.

So to my point - IS THERE ANYONE WILLING TO HELP ME GET THIS THING GOING AGAIN>>>> PLEASE!!!!!!!! Im just at a lost. Im guessing maybe replacing the valves (as one might possible be slightly bent) might help, but dont want to be throwing money into parts Im unsure I need.

Would appreciate if anyone could give me the rundown of what to look for and check.

Ok ro assuming the timing was right when you rechecked it? and it still runs.Check the 'o' ring between the intake tube and cylinder head,is the tiny steel washer that supports the o ring still on the end of the intake tube? they are real easy to lose.The only other thing is tuning.Set the hsn first and do it properly with a tach then set the lsn,if you don't do it this way you will be chasing a good tune all day.
Old 09-04-2014, 04:01 AM
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Here is the washer OF speaks of, the .62 has a black one for some reason.
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