16/1 RPM Adjustment Issues....

[Incredilion]

Greetings all;
 I have a 16/1 GM90 that I just rebuilt, and am having an issue with that I hope someone can point me in the right direction on.

My issue is RPM, I'm having a hard time getting it down low. I want it to get it down to 650 or so; but if I set it lower than about 800 RPM (running speed) it won't start (not enugh fuel?). So, just not sure what is causing it. Seems like, also, that when the machine starts & runs, after a while (a few minutes) the RPM's start creeping up, too.

Any ideas appreciated-
Chris

[carlb23]

starting should not be a function of where you governor is set as the fuel rack should be wide open at startup. Please take a photo of the governor and associated linkage and post it so we can possibly see what the problem is.

[xyzer]

You may have to change the spring tension to lower the rpm and not do it with the adjustment. It will need fuel to start! Others have dealt with this more than I and should be able to get you going.....I believe the only difference between governors on the different rpm engines is the spring..?? I will watch the replies so I will learn also.

[Incredilion]

Carl, I took a picture & now am trying to figure out how to upload it. I click on the "Insert Image" tab, and get the . I don't get this, (sorry for my computer illiteracy). I thought there would be a "dropdown box" where I'd go to the file & so on. Any ideas?

 The way I'm understanding this, when you tighten the spring, it raises the RPM's, and loosening the spring lowers the RPM's. I have the spring as loose as I cen get it, and the RPM's were still too high, so I went to adjusting the connecting linkage, making it longer, in effect holding the IP closed farther. (less throttle). As I adjusted the linkage to get the RPM's down, (they did decrease) it seemed like it was working, then when I went to start it, it didn't get enough fuel, so I adjusted it back towards more fuel (bent the connecting linkage a little) it started, slowly, and then went way up in RPM's again, as it should.

On the rack being open, not sure I get this. (Reading as fast as I can about the "rack"). Is the premise that when you open the fuel cutoff lever, that the injector pump is supposed to open all of the way, until the engine starts running, THEN it gets pulled back (to a lower RPM)?

[carlb23]

with the engine not running the governor weights are all the way in and the fuel rack should be fully open.  Once the engine starts and the governor weights start to move out the spring tension on the adjuster spring is what holds the governor weights from continuing to move out and closing the rack on the injector pump.  are you sure the governor weights are pulling on the linkage trying to close it as the engine speeds up.  Be very careful not to overrev the engine but i don't think at this point that is your problem.   To post a picture here first you must upload it to a service like photobucket then you can link the image from there.

Someone  may have a manual for a gm90 but i suspect that setting the governor on the gm90 is the same as a listeroid.

 

[Incredilion]

Carl
Thanks very much for explaining this to me. Now it makes sense.

I'm going to check it tomorrow, probably just unhook the linakge & watch what the arm to the governor does. If it moves than I'm good, internally, sounds like, right?

I'll have to register at photobucket & get the pic up.

On the manual, I've got a coulpe of them, but they don't explain how the governor works. Again, thanks kindly-
Chris

[38ac]

If you watch carefully while in operation you will see this but what's happening is the high RPM springs are so stiff that when you slow the engines operating RPM there is not enough travel left to pull the rack open when you need fuel for a load or for starting.  I have found this to be true even when going from 800 to 650 so I am certain that from 1000 to 650 what is going on. The original Listers have a device on the rack that provides extra fuel for starting and limits fuel for operating but the Indians saw that part as not necessary and dispensed with it. You need a lighter spring and can go trial and error from the hardware store or get a 650 spring fro Gary at Diesel electric.

[Incredilion]

38AC, that is excellent advice. I'm going to try to pick up a few springs in town tomorrow.
Thanks to all of you guys for SOUND advice, totally appreciated. I'll let you know how things turn out tomorrow.
Chris

[Incredilion]

38AC you had the winner!
I stretched the spring, and voila! problem solved. Now, for some adjustements.....

I have a question for you guys, though.
Thsi engine is new internally, new piston, cylinder, rings, etc. It has been run w/o load now a few times, maybe a total of an hour or so, possibly two. It is slobbering through the exhaust, for sure, I saw oil actualy dripping out of the exhaust joints. Realizing I have to run it under load (starting now) to brak it in, is there a chance of it becoming a runaway based on the excess oil?

Again, thanks in advance-
Chris

[carlb23]

most of them will slobber pretty bad when new and especially with no load on it.  Mine slobbered pretty badly when new but after a few hours at 75% load or so it cleaned up nicely.

[dieselgman]

We have also seen this common problem... definitely requires a load to break it in. Most of these even in very good shape will pass excess fuel out the exhaust if they are run without loads and/or cold.

One additional break-in aid would be using a non-detergent oil for the initial run-in period.

dieselgman

[bschwartz]

Where in this day and age (in America) does one find non-detergent diesel oil?

[dieselgman]

Tractor Supply is my favorite... also Orschelns or other Farm Supply. You can get 5 gallon pails and drums of 30 wt or 40 wt Diesel-rated oil from them. If none of these near you, your auto parts outfit can special-order it as a last resort.

dieselgman

[bschwartz]

I just checked Tractor Supplies' website, and can't find any non-detergent oil.  Do you have a brand or part number?

[dieselgman]

I will take a look next time I'm at the shop.

Dieselgman