1450 Spark Knock (14hp)?

[FLETCH14519]

Originally Posted by cooperino

Have to agree with George on this... Both counts. Another question. Does it do this from cold start? Does it get worse after warm up?

So I did notice that a engine mount bolt had fell out. Have a new bolt mounted now. Still making the noise. It only does it at just over half throttle to high throttle. Does not do it at start up.

[ol'George]

The cooling tins have a habit of rattling when they begin to disintegrate /break
apart at the spot welds.
Might do some feeling/touching on things that are suspect of noise.
-----------As far as a "knock"--
When the engine is warm, if you put your hand on the throttle linkage at the carb and slowly increase/rev the throttle, if you can hear the rod on the crank bang every time it fires, it is loose/worn.
You should not hear it when it is slowing, just when increasing throttle.
You want to just dial it on, not open it full open all at once.
That is how you hear if the rod talking to you.

Did the iso mounts look OK or had the pan started to wear into the cradle as they do?
Were the 4 bolts in the cradle to pan tight?
You mentioned one plum gone,that is usually an indication others are loose.
just some things to check, before you preform internal inspection like balance gears or crank wear.
I'm seeing the butterfly shaft dancing around?? usually that means high hours.
My guess is it needs rebuilt as well as other things that go along with that,
like cradle mods/mounts repairing broken tins/repairing butterfly shaft
Flex Disc joints/driveshaft etc. etc, typical refurbish of a good horse.

[cooperino]

Originally Posted by FLETCH14519

. Does not do it at start up.

The fact that it does not make the noise when engine/oil is cold may be a bad thing.

I still agree that you need to eliminate possibility of it being bad mounts, engine tins etc. But if they are loose they should make noise all the time.

[dvogtvpe]

If the mount bolts are falling out you probably need mounts. First, I'd start with simple stuff. Have you ever checked the timing? The carb looks pretty new? Was it ever adjusted/fine tuned? Loose tin as mentioned, can make for some odd noise. It very possible it has some piston slap, rod clearance getting loose, or the cam slapping back and forth. Start with the simple things first, KISS keep it simple stupid.