Tappety noise from engine

willy mac said:

Just had a Norton owner of many years try out something, with the front wheel against a wall, engine running and in gear we let the clutch out nice and easy without stalling and it clattered like anything, so the concensus of opinion is that it's small ends.

Click to expand...

Huh - never heard of doing this before.

i pulled over this weekend on Trixie because I thought I heard ringing/clanking sounds louder than I remembered, really, had a heart drop moment but must of just been the angle i was holding head while bombing into the sweets of Race Track Road. I've tapped many areas to reproduce the clinking to come to opinion its primarily the dense head alloy ringing like a bell from the rockers tapping on the valve stems, but same sound can be gotten tapping other areas of the head.

I do not accept the idea that small ends are a normal chatter sound source and believe the only thing the test letting out clutch with front on a wall was the lugging chugging sounds of detonation ping and knock.

A question of Rebore? What sort of clearance would you expect to see between a newly rebored cylinder and it's new piston without the rings?

Ideally usable if within .035-.045" piston-bore wall clearance though up to .055" maybe for heated racer big bore engines. Type of piston material matters some too. Ring gaps ~.0125" un-less special fuels or boosted then enlarge a bit more.

So......
lately I have been hearing a slight tapping from up around the right exhaust valve area.
Wiggling the rocker I could feel a hitch in the movement so I started thinking Thackery Spring /Washer.

This morning I pulled the rocker and took a look. The rockers have 39,000 miles on them.
I didn't find a huge step worn into them as I expected.
I polished up the ends of the rocker arm and re-installed it.

The ticking is still there (i think), but now I know that I can rule out the thackery washer.

The pics show what I found and what I did:

BEFORE:




AFTER:

Crikey . If youve got thatt far , you may as well get a set of spacers machined up . & shims ?, or measure and size to fit .

Two things with the horrible spring washers there . the edge catching in the wear mark . OR the whole Rocker Shaft shifting sideways at eaxch opperation . Against the spring . =

Slaps when it goes back . Looking to see if witness marks on valve top / rocker tip may show there ?? The Dreaded machined spacer see to that as they dont commpress .

Pushing Valve with thumb , gives a ( :? ) indication of if the Valve Springs are soft . The W&S springs are better quality than O.E.M. so run quiter , If its all Just Tappet / Valvetrain noise .
One has to watch one doesnt end up with the entire motorcycle spread out in its individual components across the floor though . . . One thing leads to another . What do you use the machine for ?

That far ?????
Pulling a rocker shaft is a piece of cake,
Heck, the whole project only took me about an hour.

I may get rid of the spring washers someday (I've been saying that for probably the past decade).
and ....There ain't nothing wrong with my valve springs.

What do I use the machine for?
It used to be my long distance bike, but now it's just my fair weather ride.
I put somewhere around 200 miles a week on it now a days.

Sounds Good . Must be all that fresh Country Mountain Air .

OK on trying to find where the "Tappety" noise was coming from I was using a stethoscope but could not pinpoint it's source as it seemed to sound the same no matter where I listened.
During the process I noticed the R/H exhaust had started to smoke and blipping the throttle ponted to things not quite right.
Head came off and revealed pistons that were sloppy in the bores and a fair way out of servicable tolerences, how I built it up like this I'll never know my head must have been elsewhere.
Anyway a +20 rebore with new style Hepolites have cured the clatter and I'm now 150 miles into the running in process.
Currently running a new single MK1 concentric with 106/250 Jets and a No 3 slide with the needle on the top groove, Bike fires up easy and once warm ticks over nice and even but plugs still look a wee bit rich, another wee thing is that it occasionally cuts out as I come to a stop is it worth going for a bigger cut away on the slide?
Pilot screw was set using a colourtune plug but could the setting of this be responsible for the cutting out?

Enlightening saga with the main surprise being the sudden onset that fooled ya till tear down. Every mile spent on nice working Cdo is points scored on how best to spend time we got left, wondering what will happen next...