Shennui 254 fuel injector pump installation instructions

What make, model and year is your engine?

Do you have a parts manual for your engine? If not you can find online parts lookup systems at places like Affordable Tractors or Circle G Tractors.

Is the part broken in such a manner as it could be welded back together?

If possible please post a picture of this part.

if you run the engine disable  , remove the compression release as much as you can so nothing binds or falls into valve train and rockers. depending where you live it might not be necessary to you anyway.

it might help you to open up the front of the engine so you can look at the timing marks on the crank, cam and injector pump gears.

I have the tractor and separate engine manuals. Let me know if I can help.