OK, another 350X question. Sorry

[Dirtcrasher]

^ thanks bud....

I'm sure grinding and lapping them does help them seat, I just wonder if it cuts the lifespan.

[fabiodriven]

OK, I got this from one of the smartest guys I know. He did motorcycle machining, boring, sleeving, and just about any other kind of work on motorcycles, dirtbikes, and ATV's out of his own shop for years (Wright Machine- Superior Sleeving).

John,
I've always used light or med grit valve grinding compound to get the valves to seat properly. Regrinding the valves is right out!!

Here's what Honda has to say...

INTAKE AND EXHAUST VALVE REFACING - NOT RECOMMENDED

The intake and exhaust valves in some Honda engines have a bimetal head and stem. A hard stellite facing is welded to the valve face and the end of the valve stem to provide a long wearing surface. This hard surface is thin and can be destroyed if the valves are ground. If a valve is burnt, warped, or worn excessively, replace the valve; do not attempt regrinding the valve face or stem.

On the other hand, the intake and exhaust valve seats in the cylinder head can be recut as often as necessary, provided the valve seat still makes contact with the center of the valve face. Refer to the applicable shop manual for valve seat width specifications.

When installing a new valve in a used cylinder head, the valve seat should be recut and the valve lapped to the seat, to obtain a perfect seal.

AMERICAN HONDA MOTOR CO., INC.
9-725 Motorcycle Service Department

[Hoosier_Daddy]

Forgive my ignorance but i read a lot about lapping valves. Waht does that mean?

[fabiodriven]

I think you put the valve in the seat along with some compound on the face where it contacts, and spin it back and forth with a little suction-cup looking doo-hickey.

[smvorndran]

I agree with Fabiodriven in post 17. My seats were pitted, not the valves, so I'm not sure what the shop will do to them. I'm not worried if they do kiss in my valves though. Both my valves had thick heads on them. I don't think Honda welded the valves though. If anything, they hard-coat the valves with a surface treatment, usually by heat or cryogenics.

smvorndran

[The Goat]

hmmmm... got the old wheels turning. how are these valves cut? I'm confused.

and if running a retardedly high lift cam... what do try cut and how?

[smvorndran]

what do try cut and how?

WHAT?

smvorndran

[The Goat]

lol iPhone keyboard while driving and not looking.

I meant... when running a high lift cam... many times I see "requires shortened something..."

what are they shortening, the guides? if so... are they just cutting and removing burs?

[SWIGIN]

for some high lift cams the retainer will hit the guide.....so you shorten them how ever much you need for clearence.

i'v done this in the past and its simple to do and figure out.