Perkins Injector Pump Timing Brain Teaser

[Sailmel]

Perkins 4-154 Injector pump timing.

Hi, this is my first post here. I’m in Florida and trying to get this puppy running before hurricane season. This question is a tuffy.
I’ve got a Perkins 4-154. I’m trying to time the injector pump because I did not know I needed to put #1 cyl at TDC before removing it. To reset the timing, the manual says to first put #1 Cylinder at TDC, then remove a valve spring to let the valve rest on the crown of the piston, then connect a dial gauge and move the crankshaft opposite direction of normal rotation .125” then back .125” to take out the backlash. This ID’s the static point of injection.
As far as the injector pump, There was not a circlip inside at the specified marks like the manual says. So I called the shop that rebuilt it. The Tech said that this particular pump has in place of the gear, a machined slot on the front that slides into a notch in the timing case. Once the #1 cyl is at TDC, with the slot and notch aligned up the timing is correct because there are no gear teeth to worry about.
Here’s the problem/question…. There is not enough room to slide the rocker arm to the side to remove the push rod to allow the rocker end to rest in the push rod tubing to have enough room to remove the valve and connect a dial gauge to take out the backlash. It appears that the only way to accomplish this is to remove the rocker shaft.
However----I’m thinking that in theory, taking out the backlash may not be important. Because since the injector pump has a slot and notch to align up instead of gear teeth, a minute rotation procedure for taking out the backlash shouldn’t be an issue.
So, due to the design of the slot on the injector pump, should I worry about taking out the backlash at TDC, and if so do I need to remove the rocker shaft to remove the valve spring? Or is it not important because of the design of the injector pump where the slot mates into the timing box?

Thanks in advance. I hope this makes sense, I´m not a good writer. Sorry if its too long.
sailmel

[Stillraining]

No ..I would put it together the way you have it..You will have several degrees of adjustment at the pump flange anyway.

[Sailmel]

Thanks for the response "StillRaining"

Anyone have an idea how to fine tune the timing usinig the marks on the flange if its off? I'm guessing its probably like manually timing regular gas engine by rotating the distributor by sound.

Thanks in advance.
Sailmel

[Stillraining]

That is exactly right...Run her through her paces under load..after you know all the air is worked out of her...if she doesn't perform well tweak her a little.