What could bend a spark plug tab?

So the scope I used was cheap with poor resolution but I could not see any damage compared to the next cylinder and I didn't have a mirror to look up at the valves. I did stick a pivoting magnet in there as well and nothing came out. I need to remove the valve cover next and see what the valve train looks like.

 

Detonation will do this.

 

Out of calibration computer operated machinery or you...

 

I checked the gap on the valves on the #5 cylinder and one of them has a gap of 42mils. It's one of the intake valves which is supposed to be 6-10mils. That is way out of spec. The valve is not seating properly. It's time to trade this one in while it has a little value. This is a lemon Taco. 12 New England winters on the frame and I never qualified for a new one. New tires, clutch, calipers, rotors, ebrake cables ............... I am disappointed in this one. Not so bullet proof.

 

If you have a questionable valve, a compression test is a must. I don't know how much trouble it will be for you, but I can't imagine not doing it.

 

In my first post I did mention that I did a compression test and it was normal.

 

If an intake valve is not seating, how can a compression test be normal? Not trying to argue but that makes no sense to me.

 

Way too early to give up. Like CurtB said, if the compression is good, the valve is seating & sealing properly. I don't know how these valve trains work, are the adjustments made with shims, or do they have adjusters? maybe it isn't as bad as you think, just need to get it figured out..

 

Stick a straw down there and suck it out

 

A friend had a no start 2 stroke bike, pulled the plug, metal chunks crammed all in the ceramic, broken piston skirt, but thats a 2 stroke. You could try, disable ignition, pull the one plug, crank the engine in hopes whatevers in there will blow out the plug hole. Maybe to be safe, also disable fuel pressure, pull the fuel pump fuse. Maybe put some cardboard above the hole so if it does fly out it won't cause damage to anything.

 

I replaced my plugs at 60k and found the last one difficult to get the socket over it to remove. Found broken ceramic pieces from the plug down in the hole.

 

I'm with you on this one. If the compression test is good the valves are seating.