Hey guys, I have a few questions that I hope you guys can help me with. I am going to rebuild my top end in my 03' kfx400. The bike was looked at by a shop and they told me that one of my cams was almost 180 deg out. I am not sure which one but that is beside the point. They said the cam lobs were still in tact and should be ok. I want to replace the valves with a set of Kibblewhite black diamond valves. My main concern is if they would be a stock replacement or will I have to replace the springs and retainers. Also will I have to do and head work(cutting,etc...)? I am also curious if they are worth the buy. I plan on using a wiseco pro-lite piston and ring set up so would this be benificial to also beef up the valves? I am going crazy and I really need the advice. Thanks.

 

Welcome to the forums mp_soldier31b. [img]i/expressions/face-icon-small-smile.gif[/img]

Just me, but I'd replace the springs and retainers if I put new valves in. Not familiar with that brand, so I don't know if you would need any head work. Wouldn't think you would.

 

Thanks Bud! Awesome response time by the way. I figured I should replace them. Do you have any recommendations as to brands? I am trying to make the top end pretty much bulletproof. I am not really interested in boring it out. I would like to add a little power while maintaing reliability. I am pretty much just a trail rider and I am not worried about crazy power. I really appreciate the help, You guys rock! Mike

 

I wouldn't do any more to the motor than I had to.

Get a Uni or K&N filter, pipe it, jet it and maybe upgrade the CDI and you should be good to go.

The 03 models had some frame issues too. Look around the shock mounts for cracking. Don't mistake paint cracking for frame cracking.

They do sell gusset kits for the frame that would take of any problems with the frame.

 

Yea I heard the same about the frame. I am looking around for a kit soon. I have a White Brothers Slip-on right now but will be replacing before the spring time. I am going to gusset the frame as soon as I get the motor out. I guess you recommend I stick to OEM for top-end? Thanks again.

 

I could see putting in aftermarket valves, since you need to replace them anyway. But unless it needs it, wouldn't mess with anything else in the motor unless it needed it.

If you trail ride a lot, you may want to change out the front sprocket to get a little more bottom end.

Heck, may want to check the chain and rear sprocket too and see if they need replaced.

Tons of parts for these on ebay. Remember, the LTZ400 and DVX400 are all the same models, just different plastic.

 

Rodger that. I just replaced the sprockets and chains before the bike quit. I appreciate the help and will post an update and let you know how it turns out. Take it easy fella' and Happy Holidays! Mike

 

OK, KB valves are good , you will need to lap them to seat properly in the valve seat. You won't have to replace the keepers or retainers , but I would replace the springs. You will also need to check the valve train after you assemble(valve adjustment) which requires shims to get the proper valve adjustment. It has the bucket type design for the valve train. 101st checking out!!!