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RUMBLEFISH

Exhaust

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RUMBLEFISH
I am trying to adjust the exhaust valve to between .017 to .019 per book. I am reading now over .21. Now do I grind down the valve seat until I can reach the specs or order a new valve? Her is what I've done so far and still would have much to go but not sure what to do. [IMG]http://i47.tinypic.com/snmpep.jpg[/IMG] And sorry about my picture but I really need to get a new camera.

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UCD
I believe you grind the end of the valve stem to get the adjustment not the valve seat. If you have to much clearance one way to get it back would be to grind the seat but you need a Valve grinding tool to keep a concentric and true grind. You could also try lapping it in but would be a lot of lapping to get .003 thousands that you need. The easiest way would be a new valve and start over.

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RUMBLEFISH
IF I grind the valve stem end then it will be even more gap unless Im missing something. Again first time for me on anything like this so I might be way off base. Thanks

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UCD
If you have less than .017 thousands clearance you grind the valve stem you can do this with a regular grinder. If you have more than the .019 thousands clearance you can grind the seat but you need a valve grinding tool to keep the same angle and be concentric all the way around the valve. After grinding the seat with a valve grinder you then lap the valve in then adjust the clearance by grinding the end of the valve stem. With the lack of a valve grinder the easiest way would be to get a new valve and lap it in and then adjust for clearance.

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HubbardRA
Use some lapping compound and lap that valve into the seat. You may lose about .001 when you do that. If you have .020, and the specs are .016 to .019, I would run it that way. As time goes by and you run the engine more, the valve will tighten as it beats itself into the seat. Even the .021 can be run with no real detriment to the engine except that you will lose a very slight amount of power because the valve is not lifting quite as far. The loss will probably not even be noticeable. You can end up spending a lot of work to get almost nothing. Just keep in mind that I will do things to my engines that others wouldn't even think of doing. You need to weigh everything you have been told and make your own decision. None of the comments are wrong, there are just different ways of addressing a problem.

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xenon172
I agree with what has been said so far but if you're going to grind the stem on a regular grinding wheel make sure you have a good jig so it is absolutely square or it will wear out of tollerence in short order. There are good deals to be found on line for valve and seat grinders from time to time. We got this old unit for just a little over $100 that has been a real life and money saver.


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