[Ultimateduster]

I recently picked up a 06 300ex for 600 running but it has a loud tick in the top end. I originally thought it was valve clearance but I adjusted it and still did it. I happen to run a leakdown test and found that the intake valves failed so I just redid the head with new valves, seal, springs, timing chain, and cam since it was alittle worn. It still makes a loud tick, is this something normal for these engines?

 

[Here 2 help]

Not exactly normal, but not unusual for an engine that old. When you redid the top end, did you check the cam chain, tensioner guides and tensioner operation?

Normally the tick is either cam chain or piston related - if the piston were scored from cold seizure, over heating or lack of lubrication (run low on oil at some point), it will tick - as long as it does not get louder or change suddenly, it will run a long time and just tick happily.

 

[Ultimateduster]

Appreciate the reply.
I replaced the cam chain while I was in there doing the valves and cam. I didn't replace the cam tensioner but it retracted and snapped back just fine when I had it out. The guides also looked good.
I don't know about its PO history with cold seizure or overheating as i didnt take it past the head other then cleaning the top of the piston and checking the cylinder walls with the piston bottomed out.

 

[Here 2 help]

OK - cleaning the top of the piston is wasted motion, but it won't hurt anything - if there was no piston material on the cylinder wall with the piston bottomed out, it probably did not suffer cold seizure, but it does not rule out overheating which may score the piston skirt. It doesn't hurt anything and like I said, as long as it doesn't get louder suddenly, just ride it and enjoy it.

 

[Ultimateduster]

Fair enough. Got me wondering about the overheating now, I should have pulled the cylinder off just to check the piston and look at the crank/rod while I was in there. Thanks for the insight and ill just ride her for now. Hopefully it will be a good machine for the wife as she's learning the transition from her semi auto to manual.

 

[Here 2 help]

Overheating doesn't damage the crank or rod unless severely overheated (near meltdown) - it can overheat to the point of dying and be fine when cooled down - usually just damages the piston and rings and if the rings are damaged, the compression drops and it's either low on power or never starts again. I think it will be fine.