'20 Series Owners Manual - errata

[Tom_Veatch]

MC# YM-20Series-A
Copyright 2003 Murray Publishing & HoyeTractor.com

Here are some obvious errors and omissions I've noted in the manual. Any of you folks care to mention any other examples you may have noted?

Hydraulic System (p. 16):

The manual specs the hydraulic system as constant flow, open center, engine driven gear pump, 1991 psi relief pressure. No argument with any of that, but it doesn't spec out a flow rate. Anybody have a source for the flow rate the system can provide?

Engine Speeds (p. 23):

The manual says the recommended slow idle is 800 rpm and "Fast idle should be set at 2550 rpm." That fast idle sounds a little high. Does anyone agree that's probably a typo and the fast idle speed should be something more like 1550 rpm.

Hydraulic Lift (p.27):

The manual talks about a drop speed valve that simply doesn't exist on my tractor. There is some raw data on this subject in another thread http://www.tractorbynet.com/forums/yanmar/86500-all-us-yanmar-owners.html. I plan on compiling that data and running some tests to verify that the service stop valve can be safely used for drop speed control as done on some other brands/models of tractors. For the time being, I have the stop valve wide open and move the 3pt position lever slowly and carefully.

 

[HoyeTractor]

but it doesn't spec out a flow rate

Although that is not even listed in many US operation manuals, it will be in a future release coming out soon.

Fast idle should be set at 2550 rpm

The "fast idle" is referring to the upper rpm limit. Possibly could be worded different but really should be obvious by looking at the next line showing working RPM.

drop speed valve that simply doesn't exist on my tractor.

That is an issue that we have recently become aware of on some models. Again, will be fixed in a future release.


Aaron
Parts@HoyeTractor.com
(940)592-0181

 

[Tom_Veatch]

...
The "fast idle" is referring to the upper rpm limit. Possibly could be worded different but really should be obvious by looking at the next line showing working RPM.

Admittedly, Aaron, I have little previous experience with diesel engines and I'm sure they have their own, specific, and unique terminology. But, until now, I had never heard the term "fast idle" used to refer to an engine parameter I had always heard referenced as "Maximum RPM", or "Never Exceed Speed", or "Redline RPM" or some other term which implied an RPM limit.

In my past experience, the term "fast idle" has always referred to an increased idle speed used during engine warmup and was usually set by some mechanical means in the throttle linkage. That misconception was reinforced by the implication in "Fast idle should be set ... " that the fast idle speed can somehow be set or controlled by the operator. I didn't consider it as an upper limit since the RPM limit is a function of the engine's design and isn't open to adjustment by the operator.

Hopefully, you can now understand my confusion. It was certainly obvious that, according to my previous understanding of the term, a "fast idle" or "warmup idle" of 2550 RPM had to be an error.

 

[California]

I had never seen Maximum RPM stated as 'Fast Idle' but that's what Yanmar used in their American manuals for the models they sold here.



Source: YM240 operating manual. (US version YM2000.)

 

[buppy69]

The MF manuals for the Japanese tractors state it the same way

Eugene

 

[BruceR]

Perhaps they meant it in the sense that the tractor was sitting idle.

Bruce

 

[John_R]

Hi Tom,

I know that this is resuscitating a dead thread but I came across it while searching for remote hydraulic installation ideas and I believe that I can provide you with some information that will help you answer your question regarding the hydraulic flow rate of your tractor.

If you look on the hydraulic pump of your tractor it should have a plate on it that lists pressure in kg/cm2 and discharge in cc/rev. I have a YM2310D and the hydraulic pump on it lists 140 kg/cm2 for the relief pressure and 7 cc/rev for the discharge rate.

Converting these numbers into English units gives 1991 lb/in2 for the relief pressure (same as your manual) and 4.6 gal/min @ 2500rpm for the discharge rate.

The electronic parts catalog I have from Fredricks Equipment doesn't list your YM2220 tractor for any of the hydraulic pumps but I would suspect that it has the same hydraulic pump as mine so your flow rate should be the same at 2500 rpm.

HTH,

John

 

[Tom_Veatch]

Thanks, John! I'll dig into it and see if I can find such a plate on mine. I've not had a real need to know the flow rate, yet, but the info will be good to know if/when I start any modifications that involve the hydraulic system.