Valve work, shop needed?

[TheChasers]

If I plan to lap valves myself(stainless steel vavles) is it required to still take my head into a machine shop to get vavle job? Is vavle job just them re-cutting the seat for new valves and installing them?

Plan was to get head resurfaced(if its needed) and lap the vavles myself, since it seems fairly easy after watching some videos.
Just not sure if there are some other things that need to be done that only the shop can perform?

 

[bweighmaster]

Not trying to be an asshole , If you have to ask , then you need to study up on what a proper valve job really entails .. Resurfacing , valve guide inspection , measurement , maybe knurling , or replacement , finish reaming ,
Seat width , angle , single ? 3 angle ? Flow relief dressing , intake porting , exaust porting , gasket matching ..
Lots to think about .......

 

[TheChasers]

Not trying to be an asshole , If you have to ask , then you need to study up on what a proper valve job really entails .. Resurfacing , valve guide inspection , measurement , maybe knurling , or replacement , finish reaming ,
Seat width , angle , single ? 3 angle ? Flow relief dressing , intake porting , exaust porting , gasket matching ..
Lots to think about .......

No worries, I dont see it as if your are trying to be an asshole.
Admittedly, I dont know what a proper vavle job entails, thats why Im asking whether its needed.
I have been doing the research though, in relation to dirt bikes and have only heard about a few on your list but the main thing I eas hearing is that the seats need to be recut with the new valves so they can wear together and be sealed properly.
But thank you, got my answer, lol. A vavle job seems to be needed.

 

[SRAD97750]

If a new valve is involved, or you've run out of valve adjustment on a valve, a full valve job by a shop would be recommended.

If you just feel like checking it's health, you can pour water in the intake and exhaust and see if the valves hold water tight.
Otherwise a leakdown check can help determine head/ring health once assembled.
-BIG DAN

 

[jbird710]

+1 to what both said. Valve seat width tolerances (valve seat to valve face contact area) on most modern 4 strokes are measured in tenths of a millimeter.

 

[bweighmaster]

A motorcycle shop only should be sought . Regular auto , truck machine shops are not properly equipped or trained in the smaller , more precise tolerances of small Hi-reving engines.

 

[TheChasers]

A motorcycle shop only should be sought . Regular auto , truck machine shops are not properly equipped or trained in the smaller , more precise tolerances of small Hi-reving engines.

Which kinda sucks. Calling around for estimate, motorcycle shops are double regular machine shops, lol

 

[bweighmaster]

I've seen some horendous methods used in some machine shops... may be better to send out to a specialist and pay a premium price for a job well done .......Kinda like using the cheapest toilet paper .... You get what you pay for...

 

[Mihylo33]

It’s California. There are probably 50 shops local that do it. There’s also Pro Circuit, and a few others that can build them up for you as well.

 

[2strokesteve89]

A motorcycle shop only should be sought . Regular auto , truck machine shops are not properly equipped or trained in the smaller , more precise tolerances of small Hi-reving engines.

Not entirely correct, some shops do very good work on both bikes and automotive, in my experience…….and, just because they specialize on motorcycles and small engine work, does not mean they don’t suck…..in my experience.

 

[bweighmaster]

Some shops suck at some things , some at everything .... I've worked in several , luckily they were pretty well run .. some I visited were just horrible .. 2 good ones closed , the worst is still going .. How ? Beats me .....