I am sure some dirt has got past the air filter so after regularly adjusting the valve clearance I am told the inlet valves should replaced.

What are the recommendations and tips from the experienced DRZ 400 owners before I start the job.

Will be replacing the timing chain at the same time.

You will need to get the seats machined as well.  Stock valves are good valves.  Probably best to do all 4.

Has the clearance gone to zero and made for hard starting or just been tighter than spec?  How often have you had to adjust, and what is the total change?

I was just on a 2500km ride and had to adjust the inlets every 1000km, one inlet has no clearance and the bike was hard to start. I got home ok but have to give the head a good overhaul and replace the piston.

get the MCCT .. mechanical cam chain tensioner

time to fit a 94mm big bore kit by cylinder works , check out E bay for a great deal

In an otherwise stock motor, you can successfully use OEM valves. After market cams, BB kit and / or lots of high RPM use, and look at some RHC valves and springs.

The head will need to be cleaned, inspected and at a minimum, the valve seats cut.

So i should change my valves and springs? jeez. i knew it!

I just bought a CW BB kit for $394  free shipping from dirtparts on ebay. Tracking says its out for delivery right now...

jawknee21, on 29 June 2012 - 12:25 PM, said:

They won't last forever.  If you don't want to take the engine apart again anytime soon you want new parts.   If taking the head off 3 months or 3 years from now is a trivial task for you then you can do it when it needs it.  Also, there is the cost of the head gasket each time you open it up.

For a lot of people who have to pay to get it done the deciding factor can be what the labor cost is going to be to do things again.

Edited by slowriding, 30 June 2012 - 01:49 PM.

New valves springs and cotters on the way with my fcr. This bike is gonna have everything. haha!