i have 04 z400 that will only start by pull starting it. the engine is making a knocking noise which would sound like the valves need to be adjusted but u cant do that on it. so we think it is the timing chain. i wana kno if anyone else has had this problem and what they did to fix it or what it sounds like to them. my friend had same problem.

 

Does it run after you pull-start it?

Is it knocking on accel or decel or both?

Will it idle?

I think a lot more information is needed here if you want anyone to have a clue what you are saying.

 

yea it will run after we pull start it and it makes that noise all the time

 

Yeah! Sounds like it could be valve adjustment. What do you mean when you say "can't do that" in regards to valve adjustment?

 

Pull the center bolt out of the timing chain tensioner. Then remove the tensioner. See if there is any adjustment left.

 

well my friends dads a car mechanic and he said that there isnt a vavle adjuster so i cant adjust vavles so he said only thing left would be that the timing chain is worn out.he is gona fix his first and see what the problem is.

 

The engine design on the Z400 (and many other newer 4 strokes) is what is known as "Shim over Bucket". On this type of motor the valves are adjusted by changing the valve "shims" with shims of a different thickness. The shims must be purchaced at a dealer. Using the instructions in the manual, it's not to difficult to adust the valves. The valve clearance should be checked on a regular basis to avoid engine damage. When the engine becomes difficult to start and noisy it's a good bet that the valves need adjustment. If you are not too mechanicaly inclined, I would recommend having a shop do the work otherwise, give it a shot. Hope this helps.
Good luck!!

 

In a sense your friend's dad is right. Any DOHC design with a cam chain tensioner and cassette runner will keep the valves in order a lot longer than the push-rod OHV engines, or even the SOHC with spool.

If the engine was run really hard for a lot of hours, the valves could have spaced themselves. People tend to be valve adjustment happy with the news quads, since everyone is still on the old mindset that a valve adjustment is needed every race or hard ride.

You don't adjust valves in car engines, or lawnmower engines, or any other industrial type engine very often at all, if ever anymore. Most engines work off the same concept so you have to wonder why those engines are not in need of constant valve adjustment like ATV engines.

The main difference comes if you are racing, or are going to be pushing your engine to it's maximum for hours at a time. Make sure you rule out everything else before you start ordering shims for a valve adjustment. I cannot count how many times I've seen people adjust their valves to fix a problem that had nothing to do with valves at all.

I've even seen dealers who are valve adjustment happy. They give you the old "we found the problem, and while we were there we noticed your valves were out of adjustment" of course 90% of the people just say go ahead and fix it.