Can't get full RPM

DaveNay

New member
I'm talking about my Oliver. I can't get the RPM up to full PTO speed. PTO speed is 2400, but the best I can do is 1900-2000. I've tweaked the carburetor every which way but loose, and this is the best she'll do. I've cleaned the sediment bowl, and changed the in-line fuel filter. I've replaced the oil filter, and changed the plugs and wires (haven't done the points yet, might get an electronic kit). Full oil change and coolant flush, replaced the air filter and cleaned the radiator screen. Heck, I've even run a full tank of premium Shell gasoline through it, but still the best it will do is 2K RPM. When cutting hay or baling on a hot day, it will even drop down to 1600-1700 when it gets hot. I'd really like to achieve full 2400RPM for operating the cutter and baler this summer, but I'm all out of ideas.
 

Archdean

Member
Two things come to mind (if you haven't already)
  1. intake gasket leaking
  2. compression is low on one or all
 

DaveNay

New member
I think old Olivers had a governor mechanism...that is where I'd start...:D

So far, I haven't wanted to mess with the governor, as it seems to be operating properly. By properly, I mean that there is no surging of the engine, obviously, if it is limiting the RPM, it's not working properly.

Two things come to mind (if you haven't already)
  1. intake gasket leaking
  2. compression is low on one or all
That is the second suggestion I have received for testing the compression, so I am going to move that to the top of the list....as soon as I go buy a compression gauge. :pat:
 

Doc

Admin
Staff member
Gold Site Supporter
So far, I haven't wanted to mess with the governor, as it seems to be operating properly. By properly, I mean that there is no surging of the engine, obviously, if it is limiting the RPM, it's not working properly.


That is the second suggestion I have received for testing the compression, so I am going to move that to the top of the list....as soon as I go buy a compression gauge. :pat:

I bolded the part I'm wondering about. Isn't your problem limited RPM? It won't go up to 2400? Sure seems like something is limiting the RPM. Why wouldn't you suspect the governor? :confused:

I'm not a mechanic, but checking the governor and the linkage sure seems easier than doing the compression check. I think I'd do those two checks first, then move on to the compression check if the other two checks didn't show any increase in RPM.
 

Archdean

Member
Since your tractor runs, check your governor this way if it passes this test move on to the compression stage!

Go up and down a small hill in 4th or 5th gear (be careful of speed) As you start down hill you should hear the engine throttle back and as you start up hill you should hear the engine throttle up automatically to maintain speed!
 

Doc

Admin
Staff member
Gold Site Supporter
I 'thought' a governors purpose was to limit the max speed / RPM. An assumption on my part from how the governor worked on some golf carts.
Maybe tractor governors are different and I have no concept of what they are for, especially from the way Dean told you to test it. :eek: :confused:
 

jwstewar

Senior Member
Staff member
A governor can be used to limit max RPM or speed. But it can also be used to raise RPMs when the load demands it and if the load decreases it will decrease the RPM to keep from over-revving the motor. A good example of this is a gas powered air compressor. Listen to the gas engine as the air compressor itself kicks in and out.
 

Archdean

Member
Governors are not all that tricky I have rebuilt several for farmall's, most recent was on my 1940 "B" (had a broken spring on the internal counter weight!! Fixed by cutting and replacing with one similar in heft from local hardware store!

I am not familiar with the Ollie's other than to say most vintage govs did and acted in a similar manner!

Suggest you buy a manual (parts, with an illustrated breakdown) and go from there! It still seems like a compression problem to me from my disadvantaged point of view!

These folks are a good place to start barr b tractor 417 962 3055 and Oliver Tractor Information
 

DaveNay

New member
Thanks guys, I have quite a list of additional things to check out now. I won't be able to get to it this weekend, as I will be working on the F150 instead
 

mobilus

Member
I had water in the diesel one time, and had the same symptoms. Have you checked your filter bowl?

I had filled up at a small convenience store and they had mass quantities of water in the fuel. A lot of people were affected, and instead of fixing the problem, they stopped selling diesel.
 
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