172 Engine weirdnesses and a question about rocker arms a...

Hi, All,

Not sure why my governor wasn't working but the
parts were worn and some galling was evident, so a
new on is on order.

The nuts on the intake/exhaust manifold were only
finger tight - which explains the chuffing noise I
was hearing. The manifold looks good; nothing is
eroded. How that hapoened I don't know and can't
imagine.

I took off the valve cover as there seemed to be a
lot of oil dribbling down from the cover. I
discovered that the oil feed tube is loose which I
assume means the rocker arms and the tube on which
they ride has been oil starved. The rockers do not
seem to be all perfectly parallel and at right
angles to the tube ;( which I assume means a few
thousand hours of unlubricated wear.

Suggestions on how to proceed much appreciated: I
obviously have to get the oil feed tube re-seated,
but I am kind tempted to try to adjust the valves
as best I can and close it back up and use it
until theres trouble.

thanks

Bill
a140346.jpg
 
Oil feed tube is a friction fit, with an o ring. The rocket mechanic before you cut the tube and installed a coupling.

You could unbolt the rocker assembly and check for wear, which is probably what I would do. You are going to want to adjust clearance anyway.

The question to ask yourself how is the rest of the engine? Does it have good compression and does it use oil? The top end looks pretty clean...
 
Compression is only in the 90s all cylinders while cranking, but with the very puny battery and crummy connections, that may not mean much. It runs. Beyond that....
 
If the valve clearances are loose that may hurt your compression numbers. You have to ask yourself why it was opened up before, valve job? Try wiggling the rockers that are off lobe.

When you run compression test loosen each plug 1 turn, then start engine for a brief short run. This will blow any carbon particles out that could prevent a valve from completely seating. Wide open throttle on a warm engine completes the conditions.

When you hit 65# or so it will be hard to start.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top