820 2cylinder

[oldiron48]

I am bring A 820 two cylinder back to life and the problem is that their are no timing marks on the flyhweel. I would like to know the best way to locate TDC on the flywheel so I can set the injectors and valve clearance.

 

[David from Kansas]

Memory is failing me, along with some other physical and mental capabilities, but, I acquired a 820 2-cyl diesel a few years ago and it ran but seemed to have a miss so I began my investigation by removing the valve cover and then discovered a broken valve tappet adjusting nut so I installed a good one, and decided to adjust all the valves, which I did. I have an operator's manual and a JD repair manual and followed the procedure listed. There must be some mark somewhere as I remember removing the flywheel cover and lining up something to be able to correctly adjust the valve lash. Maybe if I get a chance to look up the procedure tomorrow I will let you know what if I can be of any help. Maybe someone will chime in here in the meantime. Good luck.

 

[Dieseltech]

I've had to use sandpaper to find the flywheel TDC and injection timing marks on rusty flywheel edge, some marks are not stamped very deep.

 

[h3llbilly]

How far are you in the rebuild process? I.e., are you able see both the crank throw and valve events as you're turning it over? I've never worked on an 820 but I'd assume it's basically the same as most other 2 cylinder John Deere's that I've tackled with no marks. Alignment of the crank and flywheel is directly opposite of each other and that alignment is a direct counterbalance to the crank throw. You should be able to figure compression stroke and TDC by your valve events. Then count splines and make new marks.

 

[Mike M]

There is a procedure in the 720 diesel service manual where you remove an injector and make a rod with a spring and a cork and you stick it into the injector hole and use a dial indicator to locate exact TDC. You make a mark a little before and after and then make your mark in the middle.