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Discussion Starter · #1 ·
hows it going just go trx 400ex for free and when i start it i here ticking coming from top end i think it maybe a valve because its not a knocking sound, but when motor warms up fully it goes away :confused:
 

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Discussion Starter · #8 ·
ok so who ever adjust valves on this did it wrong they were all tight at tdc and while i turned the crank all the way around they were still tight i adjusted them but still ticking,
and it coming from exhaust valve on on rear brake side, i thinking bent valve from having them tight so i will be changing valves soon
 

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If a valve was bent (even just a little bit), it's unlikely the engine would start.

The camshaft has an automatic compression release built into it that opens the RH exhaust valve a few thousnadths of an inch. It is supposed to operate on the first compression stroke only. However, if before you got the machine, someone worked on it and perhaps removed the camshaft, there is the possibility that either the release mechanism is damaged or the spring and plunger in the head below the cam might be damaged or missing.

But, this still doesn't explain the tappet screw hitting the cover. The only time the screw can hit the cover is near TDC when the valve is closed. Too little clearence between the adjuster screw and the valve would not be a cause. Somehow the design clearence between the tappet cap and the adjuster screw had to have changed. To the best of my knowledge, this will only happen if the adjuster screw length is changed, the valve stem length is changed or the depth of the valve seat or valve face is changed. Your valves might not be bent, but could be damaged in another way and still will need to be replaced.
 

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Of course the timing could be off, but it still does not explain why the tappet adjusters are hitting the adjuster caps.

BTW - having compression does not indicate whether the piston is good or not. I have seen standard size pistons installed in overbored cylinders. Enging runs fine, but has piston slap and makes a lot of niose. Over a period of time the piston will break and cause more extensive damage.

Whenever I buy a machine that the owner says was "just rebuilt", I want to know who did the work, what was done, receipts for the parts and the old parts that were taken out. Some people think I'm stupid for walking away from a bargain, but after I "fix" the jewel and the repair is more than the machine cost, they're not so critical of my passing on the steal of a deal.

I suggest that you have the motor taken apart and each part inspected by a trained technician to determine what the cause of the problem is.
 
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