atc110 intake valve hiting sparkplug

[racer....X]

My sons honda 110 started backfireing. I checked it out and found the intake valve had been hitting the sparkplug. We have a parts 110 that I got last summer that I thought I would rob the head off of, but after gettting it apart it had the same problem.They both had the correct plug in them, and the parts bike had to be like that when i got it because its never been messed with scince I got it. Anybody have this problem before?

[shortline10]

Yep your timing is out and jumped a tooth or the timing chain was soooo loooose that the valve comes in contact with the piston . I've only see plugs get hit when using a pop up piston or high compression pistons . What brand plugs are you using ?

[jmax857]

Your timing shouldn't affect the direction in which the valve comes down. The valve will hit the piston if its out.

Edit: sorry I didn't read your post carefully shortline, I thought you said it would hit the sparkplug if the timing was out. I read it again and you said piston.

[atc007]

Well,my guess is you do NOT have the correct plug! You need a H series NGK plug, ANY E series will hit and BEND the intake valve. Everytime. If it has a long style plug,,like a 200 s ,e es x etc.. Wrong plug. IF by some miracle I am wrong,,then like Shortline said,it has jumped time. You want a NGK D8HS in that bad boy. Let us know what you find!

[atc007]

I reread your post. If it was running fine before and this started,yes,it has jumped time. My bad !

[racer....X]

Ok, I checked a little closer and the piston has hit the valve. I guess it bent the valve enough that the valve hit the end of the plug. I guess I just over looked the piston when I saw the end of the plug had been hit. Thanks guys.

[shortline10]

Glad you figured it out , parts are cheap for these so for about 50 bucks she will be like new again LOL .



Ok, I checked a little closer and the piston has hit the valve. I guess it bent the valve enough that the valve hit the end of the plug. I guess I just over looked the piston when I saw the end of the plug had been hit. Thanks guys.

[atc007]

Unless he turns it into one of your animals!!