Injection Pump/Governor Weight Retainer

[hodgdon42]

This is for a 450b with a JDB Roosa Master Pump. So I bought a timing window for my dozer so I could inspect and adjust the timing. Well when I went to set the static timing I can't find the timing line on the governor weight retainer to match up with the cam timing line. After doing some research on here I think that someone replaced the governor weight retainer and didnt mark the line on it? Apparently new ones don't have the timing line marked on them. My problem is that I dont have an old governor to use to set the new timing line. I read that you can set the timing line with a degrees scale but I have no idea what the specs are and how to do it. Anyone have any ideas? Could the pump have been assembled wrong? The dozer runs decent but I think it could use an adjustment. Thanks Guys

[MarkW]

That timing line can be pretty hard to see.

Additionally, the engine can be at #1 TDC but at the top of the exhaust stroke instead at TDC on compression. Anyway, please do not be insulted when I suggest you try looking again, possibly wiping the ring of the weight retainer with a Q-tip while it is at TDC, and then if you still do not see anything turn the engine 1 revolution and look again.

I managed to damage the weight retainer in my pump (embarrassing story, do a search in this forum and you can find it, including pictures) and I was able to pick up a couple pumps for parts (only needed one but found them at a scrap yard) On all 3 the mark is in a different place so I suspect you will need your pump model # to figure out where it should go. I marked the replacement with an engraving pencil and in retrospect a pass with a triangular file would have left a more noticeable mark.

[jdemaris]

This is for a 450b with a JDB Roosa Master Pump.

As MarkW already stated - the engine can be at TDC for #1 cylinder in two different modes. One is the top of the exhaust stroke and the other top of the compression stroke. You need to be at the latter or the pump will be a full turn off.

Yes the new retainer comes out of the box unmarked.
450B came with one of these three pumps.

JDB431AL2475, JDB435AL2442, JDB435MD2802
As I recall, the 435 pumps are for the turbo versions.

The JDBAL2475 gets the timing mark put onto the retain at 136.5 degrees when laid on a degree wheel chart.

Timing works like this. Keep in mind the pump only turns at 1/2 engine speed so pump RPM is only half of engine RPM. Pump timing degrees are only 1/2 of engine degrees. I.e. 1 degree of advance at the pump is 2 degrees at the engine flywheel.

JDBAL2475 PUMP timing is thus:
1 degrees at 250-450 RPM (that's 2 degrees at 900 engine RPM)
5 degrees at 750-850 RPM (that's 10 degrees at 1700 engine RPM)
7.5 degrees at 1300 RPM (that's 15 degrees at 2600 engine RPM)

The turbo pumps get the timing mark etched at a different setting. They both get marked at 138.5 degrees instead of 136.5 degrees.

[hodgdon42]

Thanks for the help guys. My pump model is JDB435MD2802. I'm going to try and static time the pump later this week. So is my pump the same as JDB435AL2442? I found a SM-2045 manual online and I'm trying to understand the timing. It says for the advance the timing should be 4 degrees at 550 rpm with no load. Thats pump rpm right? So at 1100 engine RPM my pump advance should be set at 8 degrees?

Just curious. That book also says for full load adjustment timing should be 6 degrees at 950 rpm. What is full load?

[jdemaris]

Thanks for the help guys. My pump model is JDB435MD2802. I'm going to try and static time the pump later this week. So is my pump the same as JDB435AL2442? I found a SM-2045 manual online and I'm trying to understand the timing. It says for the advance the timing should be 4 degrees at 550 rpm with no load. Thats pump rpm right? So at 1100 engine RPM my pump advance should be set at 8 degrees?

Just curious. That book also says for full load adjustment timing should be 6 degrees at 950 rpm. What is full load?

The manual on-line you're looking at is one of the oldest versions of the SM-2045. Too old to even have the MD2802 pump in it I suppose. The later version leaves out those load-timing specs. Not sure why - but maybe they were inaccurate?

Some Stanadyne/Roosamaster pumps have just speed advances, some combo speed-load advances, and others min-max advances. Speed works by RPM alone. Speed-load can advance timing by RPM and/or load on engine. Min-max only governs idle speed and top speed and nothing in-between. Min-max is often used on autos that get driven on the road. In between idle and top speed the engine speed responds to the throttle only - not RPMs via the governor.

One other feature some pumps have is a torque-screw - but I won't get into that. your pump has one but just leave it alone.

The newest manual does not give any load specs for your pump so I'd adjust by the test-stand specs. Or look in the Deere 450B manual for tune-up specs. It will probably say the same for on-engine specs.

The JDB435MD2802 is NOT the same as the JDB435AL2442. Both have the engine cranking at TDC, and the advance curve is pretty much the same for both. But - the fuel delivery rate is much lower for the 2442 pump.

[jdemaris]

My Deere manual for the 2020 ag tractor and 450B shows the timing check with the plastic window as thus: 3 engine degrees at 1400 engine RPM which is 1 1/2 marks on the timing window. 6 engine degrees by 2400 engine RPM which is 3 marks on the plastic window.

By the way if you have no timing mark, you can air-time the injection pump to the engine. Just hook an air line to the #1 port on the pump with compressed air and slowly turn the engine. When you hear the plungers snap into place in the pump it's at fire position for that port (#1 cylinder). If the engine is at TDC, then it's static timed correctly. You can then scatch a line from the window if you want.

[hodgdon42]

Just hook an air line to the #1 port on the pump with compressed air and slowly turn the engine. When you hear the plungers snap into place in the pump it's at fire position for that port (#1 cylinder). If the engine is at TDC, then it's static timed correctly. You can then scatch a line from the window if you want.

Looks like I'm going to have to try this. I turned the fly wheel over, pinned it twice and still no mark. Do you know what size thread the ports are? Just to double check, #1 cylinder is all the way to the front of the dozer?

[jdemaris]

Looks like I'm going to have to try this. I turned the fly wheel over, pinned it twice and still no mark. Do you know what size thread the ports are? Just to double check, #1 cylinder is all the way to the front of the dozer?

Threads are 3/8" x 24. I use an old injector line coupled to an air-chuck fitting - for air-timing.