Adjusting governor D6 9U

Do you notice the governor responding at lower load? Something like turning at half throttle? My experience with two different 9U tractors was one was powerful, but you had to operate with your hand on the main clutch or it would choke down when the load suddenly increased. The other one was very responsive and not prone to choking down, it would really respond. It was very noticeable at low rpm while maneuvering, the governor would respond when you hit a brake etc.

The only adjustable thing in one is the main spring. They are not supposed to be adjusted in the field, just replaced, but are not available any more, so maybe a careful program of adjustment might help. I would first inspect all the rollers, bearings and pivots etc in there for flat spotting and binding before adjusting anything.

Does it stay cool? You might get more out of it by changing the rack travel spec. But if its already prone to overheat that is no good.

I have only run it in relatively cool weather - about 70 degrees max. My problem is getting warm enough !
I have verified my water temp gauge reading at the rear of the cylinder head - about I5o or so- by sticking a thermometer in the radiator - same temp. I even drove it, pulling a disc up and down hills for over an hour with the radiator covered with cardboard. Never got over i6o. When I check thermostats they are closed.

So- no danger of overheating. CC- I did "tighten" the spring by turning it on its collar one turn. This makes it shorter and therefore stiffer. I "think " it helped.

Is that the only thing to keep tinkering with ?

It does not feel real responsive to loads, like you mentioned. It definitely slows down when encountering a load. - but it doesn't just stall instantly...

Thanks

Have you checked the RPM with a hand held tack at the hour meter?

The early engines where only set a 1400.I think it was with the 13xxx serial number when the wet clutch was introduced they upped it to 1600. From what I have seen most all have been upped to the 1600. But in other application of the D318 such as the DW 10 scraper they came factor set even higher.

I have a 9u that was set up to 1700 RPM and that made a different tractor out of it. There are now several other 9u's in my yard that may out work it. Since most have one problem or another probably never know which is the most powerful.

There are also shims that can be adjusted to give more fuel that is part of the information in book for servicing the D318 engine. I have never seen as much difference from this as upping of RPM's but some say it helps.

The current favorite 9u that is a very good pulling D6 seems to use more fuel than any of the others but dose not smoke any more than any of the rest. I guess it would be interesting to know what RPM it is turning. But this tractor is also running a very over sized dry air cleaner. With good luck I have a little more history on this machine than any of the rest,and the air cleaner is sign that other information is correct. So this D6 came from a farm that had the most noted local mechanic do all there work and provided him a building for a shop. He was known to play with fuel settings and get all that was available from a Cat.


Another thought it might be good to have Quin Cat check your fuel injectors. Provide it is still cheap and that they still have the equipment to check things this old.

Thanks Ray, I did have an offer from a CAT mechanic in Bakersfield to loan me his tach. I'll give that a try, makes sense to check all the details related.

Have you replaced fuel filters lately, or checked your transfer pump? Here in the frozen north, when fuel gels, diesels will act like they have no throttle/governor response because fuel is not being delivered to the injection pump. At the worst engine will starve and slow down like it is running out of fuel or even stall.

Your governor could be working just fine, but if fuel is not flowing at a high enough rate due to restriction or faulty transfer pump engine will not try to maintain rpm.

Not very familiar with these particular tractors, does it have a suction screen at the tank, or somewhere else that could be plugged with rust/sediment/algae?

I once worked on a standby generator that had its day tank infected with algae, black slimy stuff, that clogged filters. There is some sort of algae that can live in fuel oil, and corresponding algaecides to treat fuel and kill the stuff.

Good luck.

Thanks,

Stewart

Snowcountryfarmer,

The filters and fuel are new. I have good fuel pressure even when spinning the diesel with the pony.
I have thought about putting a ninety degree fitting on my fuel pressure gauge and face it to the divers seat. Then I can read pressure while making a pull.

Thanks