Well I took off the side panels and opened the hood and ran it

Still has the noise, so the easy fix is out of the question..

http://s1182.photobucket.com/albums/...doffrattle.mp4

There's still the muffler, muffler box, and all the engine tinwork that could be rattling.

I agree with Matt. Make sure to check the rest of the engine sheet metal. Kohlers like to rattle, especially the 16 horses. My 169 will rattle your teeth as well as the hood, heat shield, etc. I've got my fingers crossed that it's something simple for you :beerchug:. Nice 1650 BTW and congrats!

Yeah my 1650 rattles a little when it idles but it clears out as soon as I open the throttle. IMO its just the nature of the beast. Hope thats all thats wrong with yours too.

My 1450 sounded like that when I lost the rear motor mounts. The engine was tilted back a little causing the front rag joint and coupler to knock.

It does not sound like a rod knock to me

I have blown up a few engines in my time. that don't sound like a rod to me.

Sweet, that's better than a sharp stick in the eye:beerchug:
Hope it all works out.

I've been listening to the vid you posted but am having trouble hearing every thing.:bigthink:
You could remove all the tin work you can including the hood, but leave on the muffler. As much as I don't like someone to run a knocking engine, start it up an see if the knock is still there.
I f you have to do engine work, knowing what can show up on a tear down figure on a complete rebuild. Sorry but with what has happen to me in the past I don't cheap on the power plant. I don't spend more than I have to, but skimp or cheepo on a rebuild don't cut it. I had to fix too much cheepo's other people did. I wont do that on my I rebuilds.
Just remember
1.If you don't do it right the first time, you may get a chance to do it again.

2.Don't use sealer on gaskets when you reassemble the engine.

3.Take your time don't rush the repair, just do it right.

4.When in doubt get help by professional or information from people in the know.

I am rebuilding a 1450 right now. I have more in it than I wanted but it will be done right It cost more if I cheep on it and would have to do this again.
I hope I helped.

1650 with engine knock
 

to me the engine can be repaired ,with out pulling it down ,and to [mic] all parts you don,t what you have ,i have rebuilt many of the kohler engines ,,and found that none of them are very true inside ,,meaningthey were never machined true to begain with ,i have found the cam thrust faces to be off as much as ,008 on one end and .005 on the other end ,as well as in the block as well ,i machine the cam and re set up the clearance ,and have made a lapping tool to repair the block as well ,to be sure the cam is not the problem any longer ,.and if the crank is out of round ,its time to have it turned ,and new rod installed ,and i balance my engines as well .no i dont do this for a living ,just as a hobby ,i,m a retired machinist ,and restore old tractors ,the first tractor i did was a 125 cub ,and it knocked when i sold it .and i never wanted that to happend,so i found out why ,hope this helps .David

I can see the back 2 rubber ISO mounts
I can't see or feel the front 2 at all

Looks like a previous owner did the welding support bracket upgrade/weld the stabilize the 2 motor mount rails

This motor was removed for sure when it was repainted. With the care that was taken for that I'm surprised the ISO would have been overlooked.

Still stumped why I cant see the front ones at all:bigthink:
Also-how can I tell if the rag joints on driveshaft are not shot?

http://i1182.photobucket.com/albums/...otormount4.jpg

http://i1182.photobucket.com/albums/...otormount3.jpg
http://i1182.photobucket.com/albums/...otormount2.jpg
http://i1182.photobucket.com/albums/...motormount.jpg