Am I hearing piston slap? (vid)

[padgett]

Hope this comes through on video.

pulled the bike out of storage and did some maintenance to it today
-adjusted cam chain
-adjusted valves
-retorqued head
-changed oil/cleaned filters.

Been hunting down the source of a ringing noise on my engine, which I thought was the Pamco knocking around. Solved that in another thread, but I'm hearing what I hope isn't a piston hitting a valve. When the bike is running you can hear a dinging noise pretty loud, but it does run no problem at all.

Its an 82 with a mikes 750 kit. Did it myself so its possible I did something wrong along the way. It was dinging prior to going into storage, just thought it was the Pamco knocking around.

Thanks all

 

[xjwmx]

" I'm hearing what I hope isn't a piston hitting a valve."

you could unscrew all the valve adjusters and if the noise doesn't go away it's definitely not a piston hitting a valve. if you don't hear it, put them back into adjustment one by one and listen

 

[padgett]

forgot to mention i did do that. But figured it could still be a valve because the rocker arms still do push the valves down even with the adjusters are all the way out.

It didn't make the noise go away. what had the greatest effect was cam chain adjustment.

" I'm hearing what I hope isn't a piston hitting a valve."

you could unscrew all the valve adjusters and if the noise doesn't go away it's definitely not a piston hitting a valve. if you don't hear it, put them back into adjustment one by one and listen

 

[xjwmx]

forgot to mention i did do that. But figured it could still be a valve because the rocker arms still do push the valves down even with the adjusters are all the way out.

It didn't make the noise go away. what had the greatest effect was cam chain adjustment.

in that case, turn it slowly and with your other hand on the rocker see if you can feel the piston tap the valve. i had some weird noises when turning by hand and it turned out to be a bent up starter spring catching on gears. you could take the right cover off and look for stuff in there. if it's not valve, it's probably something you can see. since cam chain adjustment makes a difference, did you put on a new cam chain? you can also take the chain adjuster all the way off and examine it. also -- you can turn it with a wrench on the generator rotor nut. don't have to kick it

 

[padgett]

in that case, turn it slowly and with your other hand on the rocker see if you can feel the piston tap the valve. i had some weird noises when turning by hand and it turned out to be a bent up starter spring catching on gears. you could take the right cover off and look for stuff in there. if it's not valve, it's probably something you can see. since cam chain adjustment makes a difference, did you put on a new cam chain? you can also take the chain adjuster all the way off and examine it. also -- you can turn it with a wrench on the generator rotor nut. don't have to kick it

I can't remember if I put a new chain on there when I rebuilt it. Im leaning towards no.

I think i isolated it a bit more today. Noticed that it makes the noise and you feel the bump specifically when the exhaust valve closes, but before the piston gets to TDC. It does it on each cylinder.
I took off the advance rod and stuck my finger in that hole just to see if I could feel it 'jump' and sure enough, it does. Same time every time, right when the exhaust valves close.

As far as timing chain adjustment, i got it to the point where the plunger is even with the housing. Bikes running fine and I haven't run out of timing adjustment, so i dont think its stretched, and if it is its still adjustable.

 

[xjwmx]

I took off the advance rod and stuck my finger in that hole just to see if I could feel it 'jump' and sure enough, it does. Same time every time, right when the exhaust valves close..

when the exhaust closes on one cylinder, both of the valves on the other would be up. unfortunately if it involves the mechanical advance, i've never worked on this one. maybe gary or 5t 's arena

 

[padgett]

Well i think i got it sorted.

i read some more about other ways of adjusting the cam chain, and i guess i had it way too loose. I adjusted it with the engine not running.

Decided to tighten it up quite a bit, until it was actually hard to turn, then backed it off. started the engine, and adjusted until the noise went away, then backed off slightly.

How i have it now is the plunger goes in and out a couple milimeters as the engine runs. Im just surprised I had to tighten it down that much. I only have enough room for the acorn nut now. Cant argue with results though