New valves for 81 185s.

[79fordblake]

I have new valves and valve stem seal ordered for my 1981 Honda 185s. Local machine shop said they can do the valve work no problem and would cost about 50 bucks if everything else checked out ok and they told me to bring the spec sheet for it so they will know all the tolerances and what degree to cut the seats.

I wish I had went into more detail now but I didn't. I have heard the Honda valves have a special coating on them. What do I need to tell them so they don't mess up my brand new valves? Shouldn't they at least be lapped in or are they supposed to be just stuck in there with nothing done to them?

When I was in diesel school we always ground and lapped the valves to make a perfect fit to the valve seat.

[tri again]

Whoa, you're right!

If the seats are stock and not beat and the valve faces are 'stock' new oem?
I'd still lap them and use that blue dye to see where they mate, but the valve guy
at the machine shop should know all about that.

Generally seats and valve faces are off by a degree or so that they will meet at a perfect line
right in the middle.

As far as Honda valves being coated? I really like to know the rest of that story.

Did you know there are shop manuals for free here under
'world class help'?

Adobe acrobat reader version 4 (old and really small version)
is enough to open them too.

Someone else on here knows more for sure.

[79fordblake]

I have the Clymer Honda manual and it says the valves can not be ground b/c it is specially coated. So what I am wanting to know is can they be lapped in? Or are they supposed to just be put in right out of the packaging(which makes no since to me). I would be afraid the valves won't seal if they aren't at least lapped to the new cut valve seat.

I ground tons of valves in diesel school and never heard of any that had special coatings and couldn't be ground until I started dealing with old Hondas.

[MonroeMike]

http://www.3wheelerworld.com/showthr...149#post732149

[tri again]

I have the Clymer Honda manual and it says the valves can not be ground b/c it is specially coated. So what I am wanting to know is can they be lapped in? Or are they supposed to just be put in right out of the packaging(which makes no since to me). I would be afraid the valves won't seal if they aren't at least lapped to the new cut valve seat.

I ground tons of valves in diesel school and never heard of any that had special coatings and couldn't be ground until I started dealing with old Hondas.

I want to know about that special coating too
but not time to read the manual.
Gotta go look at 2 new sx's, orig owner trikes.

Pls let us know if you find out the big secret.
Thanks

Oh wait, again, MonroeMike pulls through.

Perfect short thread that makes sense and a quote from honda usa.
Valves are stellite faced but the seats can be dressed up.
Grinding some valves can grind away the stellite surface.

As I recall, stellite was the big valve topic when the USA went to unleaded gas back in the
what? 1970's?

[79fordblake]

Thanks that was a straight forward post, lol. The new valves should be lapped with the re-cut valve seats but never ground.

[tri again]

Thanks that was a straight forward post, lol. The new valves should be lapped with the re-cut valve seats but never ground.

boy, it sure sounds that way.

Then again, didn't they say 'some' honda valves are like that?

There should be a way to know for sure.
Then again, we may be over engineering this and it will simply go back together without
much fuss or grinding of anything.
It's nice that we only have to do these things on average, 4 times a century, eh?