LTZ400 valve clearance problems

[wayne1ca]

'06 Quad would not start. The intake valve clearance was less then zero. I changed the tappet shims and got proper clearance. Within 20 hours the clearance went to zero. I changed the shims and again within 20 hours were back to square one.
I read on another forum that once this happens the valves are shot. Can anyone verify this? Sould I also replace exaust valves? I am considering after market springs and valves. It in not fun removing the head.

[pnywening]

your valves are cupped. it is very common on these machines. get a set of kibblewhites or ferreras. if you are pulling the head you might as well do the exhaust valves as well. it is not bad pulling the head if you havent done it before get a manual it will walk you through it. now would also be a good time to change your cam chain to a good d.i.d chain z400s are notorious for stretching stock chains.

[wayne1ca]

Thanks for reply. I will do that.

I failed to mention that I replaced the cylinder on the first go round due to some grooving at the top. The ATV shop inspected it, and advised. What they failed to do, was tell me about the valve problem. Probably because I was doing the work. @ $96.00 an hour I will do it myself.

For those that may ask. Compression was @ 58psi before.
After it was 150psi. Throttle was held open for this test.

[cataway]

when your looking at valves your going to get what you pay for the best valve for the ltz400 is a valve offered by RHC

[pnywening]

for 99 percent of applications kbs and ferraras are more than sufficient they are one piece valves where the stockers are a two piece setup.

[cataway]

RHC are Ferrea's but have been treated to make them harder, if off the shelf ferreras are use then your most likely only going to get a few hours out of them, ya been there done that, infact your better off putting in stock valves than off the shelf ferrera's and btw Ferrea's are a two pice which in this case is better.

[wayne1ca]

I am thinking I will install a DRZe kit. Would you recommend this?
I don't want to tear this head off every few hours.

Can you tell me who sells the RHC's.

[cataway]

http://www.ronhamp.com/company/contacts.aspx

[2muchquad]

do you have a aftermarket cdi by the way?i have a 05 and i havent had any problems...yet.I have the 440 kit for now with a fcr and exhaust and i run it pretty hard..hopefully i didnt just jinx myself:( do you have an aftermarket cam?if so you may need stiffer springs,they will actually help the the valve ride the cam lobe instead of slamming into the seats.a lot of p[eople are not aware of this.;)

[wayne1ca]

Everything is stock. Just trying to get it running realiably. It belongs to my son inlaw and since I will finance the repair, don't want to spend a bunch of money.