71 knock/click Burned valve pics

I shored up my leaks and the bike was running great... got an idea to take a ride out to the beach and enjoy the day at the Primer Nationals with my wife. A jaunt over the hill, through some canyons then out through some historical agricultural land before popping out at Ventura. Was a great day, went there without problems. Also ride around town during the day with no issue at all. Tons of people complimenting the bike and all was well.

Till the route home of course!

I start off home and the bike runs great for about 40 miles. As I am cruising along at about 65mph I hear a knocking sound. Then I immediately pull in the clutch and coast to a stop. I pull over and of course I am in the worst possible place someone can get stuck, I am along side a highway that is riddled with big rigs and tons of weekend traffic. It is so loud I cant hear myself think.

So a guy rolls up on an old 70's BMW R series with a touring cowl. He gives me some advice and lends a good word or two but has no way to really help. He rides on and then another rider pulls up, Hes on a real nice 1200 bandit. He offers his truck to me and everything. Was real nice to see someone out of the blue just pitch in to help a fellow rider like that. There are some real good people out there!! I don't even want to share the sheer number of Harley dudes that passed by without stopping. Then right after he leaves, a guy with a slammed 64 impala pulls up and gives us a few waters and offers him tools. Another cool person! Lots of nice people willing to help out there!

Back to the issue,

I start the bike up and hear a loud clicking inside and it sounds like it comes from the timing cover. So I get the bike home and pull the timing cover and see everything looks good. I know I recently rebuilt the oil pump and had the timing cover off so that was my first suspect. But it looks good.

Then I think about possibly the trans being the issue. I don't remember if it was clicking with the clutch in or not. So I put oil back in and fire it up then hold the clutch in. I notice the clicking continuing.

I then notice a backfire.

Anyone have any ideas what this could be? Here's a list of facts

Loud clicking inside motor *sounds* like it comes from the timing side.
Clicking remains when clutch IN
Backfire occurred (scared to run the bike too long right now)
Bike still starts

no evidence of anything "grenading" in the oil.

recent work performed:

timing case seals replaced
oil pump rebuilt
trans outer cover seal replaced, shift oring replaced
Primary chain adjustment
Drive chain adjustment
crank oil seal replaced

Re: 71 norton mystery knock/click

ugh I just did a compression test and the left cyl has 0 pressure!

Also the left plug looks kinda lean.

This is going to be fun.

I think ms cleo predicts I am going to lose some money soon.

Re: 71 norton mystery knock/click

Dam that Ms. Cleo!! I smell a flim flam. Can you see the valves thru the plug hole. You could rule out broken valve heads that way. Also pull the rocker covers and check for adjustment/broken bits or jammed open valve. You could get lucky and it only be a valve train issue and not rings/piston. Hope it's not something big. We've all been there, it sucks. My 850 ate itself, but made it home.

Re: 71 norton mystery knock/click

Bummer. Start small and work up. Check valves like wolfie says, you can peer into the head pretty good by taking off the headers. Push it over with no plugs and watching the tappets. Check your electrics too. 0 psi in one and it still runs strong, not like a big single? Be careful not to damage any more.

Dave
69S

Re: 71 norton mystery knock/click

bwolfie said:

Dam that Ms. Cleo!! I smell a flim flam. Can you see the valves thru the plug hole. You could rule out broken valve heads that way. Also pull the rocker covers and check for adjustment/broken bits or jammed open valve. You could get lucky and it only be a valve train issue and not rings/piston. Hope it's not something big. We've all been there, it sucks. My 850 ate itself, but made it home.

Click to expand...

I can see the valve opening and closing with plug off.

I can see valve train moving for both intake and exhaust side with covers off.

I push my finger in the hole then give her a pump but she don't respond. that's a sad thing!

I also notice the intake valve When closed the rocker is 1mm play from the valve!!

Its funny, last time I had an oil leak and I ended up with CNW hubs, PWK carbs, powder coat wheels, buchannan spokes, new exhaust, fork rebuild and of course the sump breather and then the new oil lines

If I need a valve adjustment maybe I really need hagon rear shocks, js pistons and rods, cam, and maybe the cool fork internals and every other damn thing I can get my hands on....



Seriously though I am going to adjust the valves and see if that brings pressure back to the cyl. I still need to understand that knock or click that was happening.

Re: 71 norton mystery knock/click

Check your valve clearances. If one is way off, one of your lifters could have lost the stellite pad.
Bill G

Re: 71 norton mystery knock/click

Bill G said:

Check your valve clearances. If one is way off, one of your lifters could have lost the stellite pad.
Bill G

Click to expand...

Yes one is way off. Stellite pad?

Re: 71 norton mystery knock/click

I had a mystery knock and when I did the rocker adjustment (one exhaust tappet was very loose), the knock went away.

Re: 71 norton mystery knock/click

The stelite pad is on the bottom of the lifter, it is the part that rides on the cam. Somewhat common problem.

Re: 71 norton mystery knock/click

I had this happen to me once. I was foolish enough to reset the rocker clearances and keep riding. Completely wore off one lobe on the cam and circulated metal particles through the entire engine requiring a complete rebuild. Live and learn ...hopefully.
Bill G

Re: 71 norton mystery knock/click

Drain the oil and remove the sump filter and check for metal in the oil and filter. This would be a pretty good indicator.
Bill G

Re: 71 norton mystery knock/click

Bill G said:

Check your valve clearances. If one is way off, one of your lifters could have lost the stellite pad.
Bill G

Click to expand...

I found some old lifters and noticed what the "stellite pad" is. I measured it at 3mm....

Re: 71 norton mystery knock/click

Bill G said:

Drain the oil and remove the sump filter and check for metal in the oil and filter. This would be a pretty good indicator.
Bill G

Click to expand...

Well my original thought was something got bungled up in the timing case. So the first thing I did was remove the timing case and the oil sumped back down into my pan. I looked at the oil carefully and it is clean as a whistle. No chunks or haze of metal bits small or large..

I haven't removed the sump plug yet though so I will be doing that tomorrow morning.


Safe to say I should remove the head next if nothing found in the sump? I don't want to cause any more issues.

I did readjust the valve to spec and it didn't cure my compression issue. I still have 0lb in my left cyl.

I think it is safe to say I have graduated into the bigger issues to troubleshoot than just a few leaks! This one is a little bit more serious.

Re: 71 knock/click left cyl 0lb comp!!!

Ice
Really sucks but we're here for you.
Take it one small step at a time and let us know what you find and the real pros on this site will get it straigtened out.
Since you have two carbs and left plug looked lean you may have burned through a piston.
Is the bluing on your pipes same on both sides. If not carb on left may be out of adjustment and running too lean.
If piston holed I'd look for some debris in sump plug screen.
Bob

Re: 71 knock/click left cyl 0lb comp!!!

Just occured that you may have lost top of left piston if they are the type with the oil slot that cuts half way round piston.
Pretty common problem with those pistons.

Re: 71 knock/click left cyl 0lb comp!!!

Could also be a bent or sticky valve. ?
And / or a bent pushrod from the above.
Would give not much compression, AND make a lot of noise AND some extra tappet clearance. And yet still run on both cylinders (sort of).

Zero compression is not much compression though....

Re: 71 knock/click left cyl 0lb comp!!!

Off with his head! Time for exploratory surgery. You could have "burned a valve", the seat having a notch in it.

Re: 71 knock/click left cyl 0lb comp!!!

Pulling the head is not a bad idea and could tell you if some of the other things mentioned here are the cause of the noises.
Be careful though. That was what I did when I lost a stellite pad and with the head off I found nothing wrong. Put it all back together, set the rockers and rode it 30 miles to work. By the time I got there the ticking was coming back. I reset the rocker clearances and rode home. Ticking was again very bad. That was when I drained the oil and found lots of metal in the oil and on the magnetic drain plug. That metal was my cam and lifter being ground away.
If you shut the engine down right away maybe you have not started wearing away the cam and lifter. As I remember the pad was on the bottom of the crankcase when I tore the engine apart. I am not sure but maybe with the sump filter off, a little probing could find the pad if that is the cause.
For me ... on the bright side, I had been saying I wanted to repaint the frame and do a ground-up rebuild for some time. 4 years later I probably still would not have done the restore if that pad had not come off.
Good luck
Bill G

Re: 71 knock/click left cyl 0lb comp!!!

More thinking here.
Pulling the head is a good idea but if you find nothing pull the cylinders too. It is not that much more work and then you can see the pistons, lifters and the cam ... and you will know for sure if any of these are the cause.
Bill G

Re: 71 knock/click left cyl 0lb comp!!!

Have you looked at your throttle slides? My bike swallowed part of a slide once and made some rattling noises in the process. After the noises stopped it ran roughly and blew black smoke from that pot.
Somehow the piece got past the valves without damaging them, but I imagine it could have bent a valve if I hadn't been in luck. Just a thought.

Martin