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View Full Version : Grind 'em?


smokeyhonda
03-30-2004, 09:53 AM
Clymer states that the valves in the honda atc engines are specially coated and failure WILL result if it is removed. This has been challenged in another thread. So, how many of you have succesfully ground their valves? The specific engine I'm interested in is an 82 200.
Howdy
03-30-2004, 10:50 AM
I have ground the valves in a couple machines and never had a single problem. The one motor was out of a Late Model 125m ( it has a atc200 head on it ). This motor was put into a 1988 TRX125 ( The Wrecker ) and has been running good for over 5 years. I did the valves in my 350x also and it runs like a top also. It was done 2 years ago.

So, I personally don't think there would be a problem.
Has anyone else ground their valves?
Howdy
thefox
03-30-2004, 11:39 AM
Bought new valves for my last 200s and ground them in, no problems. I have reseated the old valves in my friends 200s and several yamahas and have not had any problems with them so far.
Mobular
03-30-2004, 12:40 PM
I do believe that what the manual is trying to tell you is in the event the valve tip is mushroomed do not grind it smooth. That is the end that is specially heat treated. The large valve head is always servicable, so grind/lap away!
bbechtel16
03-30-2004, 02:04 PM
I don't know much about internal engine work, but I don't think them refering to the tip would make any sense because then the cams/rockers wouldn't open the valves as far? Anyone follow me and agree/disagree?
Mobular
03-30-2004, 06:23 PM
Even if it were ok to grind the tip, the adjusters would take up the slack. Your lift is determined by the cam, and any geometrical lift lost from the different rocker angle is extremely negligible.
Again the tip is hardened, and any grinding there will seriously impair the rocker to valve durability.
bbechtel16
03-31-2004, 09:40 AM
Ohhhhh, I get it now... If you ground the valve tip when you adjusted the valve clearance that would take up the space is what you're saying?
Mobular
03-31-2004, 12:14 PM
Yes, but DO NOT grind the tip and reuse! It has been heat treated for long life. With that surface removed, it will wear almost instantly. The manual recommends grinding only to remove the mushroomed end to remove it from the head.
fishy_inn
03-31-2004, 06:01 PM
What does grinding the valves mean?