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how to install new valves

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I have purchased a new set of valves and wish to install on the old head but the seat on the head needs a little tidy up, my question is this, can i use the old valves and some paste to tidy up seat or is the head titanium coated or just the new valves?

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You must have the seat's ground.If you are using s/s valves lap them in if using ti valves just put them in. Do not lap in ti valves

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A worn valve used to lap the seat would yield a poor fitting seat as the angle would be incorrect. I doubt lapping compound would touch these seats anyway.

Some SS valves are also coated. Do not lap them either.

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I have just had my valve seats re done (inlets only, pricey excercise to get all done). The specialist I went to fits copper berylium seats to the bikes and then cuts them at slightly different angles to stock. He uses the copper inserts because they are softer and cushion the valve better. He has changed the angles to better seat the valves. He placed spacers under the springs to pretension them also. I am now running Exceldyne Ti valves. Put the bike back together and started them up. Both bikes run great and the RMZ250 is noticably better as it was older and probably worn more. He believes that the valve issue is due to the hard seats that are not compatible with the soft standard valves.

My left inlets went late last year and I put new valves in to get me past christmas and until I could have the above work done. The new valve in the RMZ did not last long at all. At least have the seats re cut.

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So how long did your replacement valve last? I'm curious because I just replaced one intake valve & spring (with stock) until I can do the whole job with SS valves. The seats looked fine.

Also if I used a dremel with wire wheel to clean off some carbon would that have damaged the valve coating?

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The replaced valve did not last very long at all, maybe a couple of rides. The bike belongs to my wife and although she rides it well she does not spend any time near the rev limiter. I thought the seats looked OK but I was proven wrong. I suspected that the new valve would chop out and it was a quick fix to get the bike going again until I could have the proper work done.

I'm not sure about the dremel. I took to an old wornout valve with a brass wire wheel on the bench grinder and it appeared to bring it up fine. It was shiny again and did not appear to have any damage but maybe I can't see the finer damage. The problem with these valves seems to come from wearing through the Ti coating. Any polishing, grinding etc would have to be wearing that surface. :cry::cry::cry::cry:

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