Valve seats replaceable?

[hondaREX]

I lapped my valves, well 3 of them as I left one in the box with my cylinder getting bored. The one exhaust valve i did have, lapped great, but the same valves seat in the head didn't lap as well. It isn't as centered, or symmetrical as the rest. Did anyone else that has done their own lapping run into any problems? I don't have a tool to accurately check the guide but it feels the same as the other 2 I have with the wiggle test. And the valve I'm missing is the other exhaust so I don't know what that one is like yet. The 2 intakes lapped perfect. So are the valve seats replaceable? Or can they be ground? And if they can be ground, will the rockers need adjusting? Thanks

[hondaREX]

After I got home and read the manual is saw you can reface the seats. Has anyone had this done? And do you have to shorten the valve or adjust the rockers after?

[hondaREX]

So nobody has had there valve seats refaced? Anyone know a way to check the valve to valve seat seal? Fill the combustion side with a fluid and watch for seepage from exh side? I know compression is way more pressure but it would show something.

What would u guys do? Can u get one seat refaced, and that valve and guide replaced? I talked with a couple guys and they said it SHOULD be ok but no promises. What damage is possible? Please help. Im about to reassemble and dont want to burn my engine

[CJM]

Never had to resurface or replace mine.

Wanna see if it leaks, put it back together and see if oil seeps down.

[punk rock kiel]

on a 400, you shouldnt have to replace the seats. get new valves cause they wear more than the seats will and the stems will taper in the guides.

[hondaREX]

Well i looked at the valves closely today. It looks like both exhaust guides are burnt.... if thats what youd call it. If i look into my guides from the combustion side, the 2 exhaust valve guides have a burn spot 1/3 of the way up. Looks to be in the area that is the thinnest, in the exhaust post, where the guide sticks into the port. On the 2 intake valve guides, they look perfect, or as can be expected from a 10 year old quad.

Also, i noticed that the 1 exhaust valve i had, looked to show a wear line on it. Its located about where the burn make is in the guide. The 2 intake valves had a "normal" wear mark where the guide ends on the valve.

Ill try to post a pic of the valves. Im going with a SERDI 5 angle valve job to clean everything up and start fresh. Not sure if im going to replace all the guides or just the 2. Also, plan to have the valves measured to see if they are bad. Fingers crossed, budget is already blown.

What are you guys thoughts? Replace all guides and valves or measure and see?

[hondaREX]

Here is the best shot i could take of the valves i had. The 2 intake valves are on the left and right of the 1 exhaust valve. The black lines in the background are referencing where the "wear" marks are.

[Blodg]

The cost of the valves is relatively inexpensive so if the motor is 10 years old I would definitely replace them. That way you won't have to rebuild for another 10 years.