[Jawb1]

I have a 2001 400EX it's got a completely brand new head new piston new cylinder freshly rebuilt stock bore with less than 2 hours on rebuild brand new heavy duty timing chain guides and tensioner. I have adjusted the valves four or five different times and still I have a ticking sound I can't hear it at idle I can only hear it when I rev the engine! It seems to run good with plenty of power I've got a 42 pilot jet and a 170 main jet big gun exhaust two holes in the airbox lid. Crankshaft had minimal place side to side and zero play up and down. I am clueless to what this is but it doesn't seem like the normal Honda tick just need some advice on what to check or what to do.

 

[Here 2 help]

Most 'tick' during acceleration comes from: 1) timing chain 2) piston slap 3) pre-ignition

1) was the timing chain replaced? Where do "heavy duty" timing chain guides and tensioners come from?

2) although the cylinder and piston were new, what was the piston to cylinder clearance and were the rings installed with the right side up?

3) what grade of fuel are you using, what brand and how old is it?

 

[Jawb1]

Everything was replaced at the same time as rebuild timing chain was from the Honda 450 brand new. This was my first rebuild and I bought the piston and cylinder together as a kit so i didn't even think about checking the clearance. And I use regular pump gas. Should I use premium gas. And I installed the rings according the the partzillas instruction video Online

 

[Here 2 help]

WHO'S BRAIN DEAD IDEA WAS IT TO PUT A 450 CHAIN IN A 400? The 450 chain is too wide for the chain guides.

Yeah I know the 450 chain is cheaper - it's cheaper because it is lighter - it is also wider than the 400 chain and does not fit the sprockets. The ticking may be caused by the chain walking from side to side on the sprockets and it can also walk up on the sides of the guides and cut the ledges off the sides of the guides. Now you also say you replaced the tensioner. You bought it new from Honda? The tensioner is the spring loaded pusher and it pushes on the tensioner guide.

And yes, the gas should be 93 octane - you can use 91 octane if it is not blended with ethanol - ethanol blended fuel should be used within 15 days of purchase and non-ethanol fuel should be used within 90 days of purchase.