DK40Se HST ground speed question

[MotorSeven]

I've had this feeling of sluggishness. So, I used my Garmin to check the groundspeed of my Kioti. Loader arms only & with a 6' brusch hog hanging off the back, I can only get a max of 11 mph on level ground @ 2500rpm. My elevation is about 1200'.

The specs say, unloaded it should be doing 15.6...what gives? Island & other DK40 hst owners, can you check this for me? I am just wondering if something is wrong, or if this is normal after 300 hrs. Everything works fine, but I have found myself using high gear more and more when perviously mid range was sufficient.

or...I could be going a little cr aaa zzzey.

RD

 

[Dmace]

Typically the top speed is at the "Rated RPM" or max engine speed of the tractor just like the HP ratings which is 2600 rpms for your tractor. I doubt an extra 100 rpms will raise your speed by 4 mph but also keep in mind that the max speed is with Ag1 tires. Which tires do you have? It could also be a pedal adjustment that is not allowing the full travel of the HST pedal...

I remember some having trouble with "bending" the HST pedal of some smaller CK models and not realizing until it didn't move at all.

 

[MotorSeven]

I have Ag1's. I will take a look at the HST pedals, but I think they are using all they have. 2500 or 2600 makes no noticable difference on top end speed. Since the ground is nice and dry/hard I think I will go dig in the slate bank across the road & see if all 4 spin like they did last year.
My dealer is not far away, so I might just bring it in & have them check the pump pressure.

RD

Wait a min....could it, naw......my new roll cage and steel roof.....killing the areodynamics ;>o

 

[MotorSeven]

Ed....are you there?? I am disappointed....I figured you would have been out there at midnight running up and down the island with a gps in one hand, then posting your findings.....................{sniff}

RD

 

[MichiganIron]

The HST Transmissions in the SE Series tractors are a little unique since the swash plate in the trans is controlled by a mechanical servo. It isn't directly mechanically linked to the swash plate like the CK series HST's, but there is an adjustable link from the pedal to the servo control.

Here are some thoughts:

Check the linkage between the HST pedal and the Servo. There are specified lengths for each linkage in the system. If you are interested in checking it yourself, we can send you the specs. Most probable cause is a linkage problem of some kind.

The hydraulic fluid has the wrong viscosity. What hydraulic fluid have you been using. This is a pretty normal cause for disappointing HST function.

The HST Filter needs replacing. Another normal cause.

The piston o-ring on the servo piston is worn, or the control spool is sticking.

The charge pump relief valve isn't functioning properly.

Hope this helps.

 

[MotorSeven]

I just did a complete fluid/filter change about 70 hrs ago. I used Multi Guard Premium Tractor hydro fluid(I looked on the bucket & didn't see the viscosity listed anywhere).
Thanks for the offer on the linkage specs, I will PM you with my EM addy. I definatly want to check the easy stuff first before I drag it into the dealer.

RD

 

[IslandTractor]

Ed....are you there?? I am disappointed....I figured you would have been out there at midnight running up and down the island with a gps in one hand, then posting your findings.....................{sniff}
RD

Sorry, I was on island this weekend but did not see your post until off island this morning. Afraid it may be more than a week before I get back out there with GPS to check speed. I will say that I'd be shocked if it was only 11mph. I get going fast enough that the ride on our island dirt roads is just plain uncomfortable even on the smooth bits. I've never checked as I've sensed that 15mph was about right.

Will put this on my list of to do's but again, I won't be out there again until the July 4th weekend.