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Eric D
07-09-2007, 08:26 PM
Ok, I installed a Tiny Tach on my Kawasaki FH721D (25 HP) a few weeks back. This engine powers my Toro Z555 Z Master, 60Ē deck. Total time is 294 hours. Now Iím starting to think I have a problem with the engine governor. How close should the governor hold the set engine speed? My Kawasaki seems to wonder from 3450 to 4000 rpm. Does this seem excessive? When first started and after warm up, full speed will show about 3600 rpm. Right after PTO engagement it will drop to 3450 rpm. While cutting it will find its way back up to 3500 to 3600 rpm. Then when Iím done cutting and disengage the PTO the rpm might jump up to 3950 to 4000 rpm.

Does it sound like I have a governor problem or should I just turn off the tach and quit looking at engine speed?:confused:

Thanks,

Eric D

MowerMedic77
07-09-2007, 08:51 PM
Then when Iím done cutting and disengage the PTO the rpm might jump up to 3950 to 4000 rpm.

Does it stay at 3950-4000 or does it level back off ? Everything you have stated up to that point sounds normal to me.

Eric D
07-09-2007, 09:58 PM
Does it stay at 3950-4000 or does it level back off ? Everything you have stated up to that point sounds normal to me.
No, it doesn't level back off. It will stay at the higher rpm. It is as if the rpm is being controlled more by load then it should. I believe the load difference might be the hydraulic system being up to temp requiring less power from the engine allowing it to drift to the higher rpm. But I really donít know.

I appreciate your input,

Eric D

Restrorob
07-09-2007, 10:07 PM
should I just turn off the tach and quit looking at engine speed?

Had you not installed the tach you may not have discovered you may have a problem until something major happened.

Check/clean and spray lube the carb throttle and governor shafts, I have seen sand/grit get in these areas and cause this. Also clean/lube all the throttle control arms/linkage.


If this does not solve your problem you may want to check the governor adjustment as below (when cold).

Off topic here but do you disengage your pto at full throttle ?


http://i107.photobucket.com/albums/m314/Restrorob/Kawasaki/FH/FH721DGovernorAdjustment.jpg

Bill Kapaun
07-10-2007, 12:36 PM
Different engine and slightly different problem, but-
I had a Briggs in which the throttle plate shaft had gotten varnished up in it's bushings.
Ditto to what Rob said.

Eric D
07-10-2007, 12:43 PM
Bill,

I think you and Rob may have the answer. This coming weekend when I can find a second or two I'll check out all the linkage and make sure it is set per the manual and check that everything is free moving. I'll report back what I find.

Thanks,

Eric D

Eric D
07-14-2007, 07:21 PM
Rob,

Thanks for your suggestions on my governor issue. The throttle shafts and all connecting hardware were fine. They all move very freely. What I found, I went through the governor arm installation per the manual. It was out of adjustment. I really didn’t think this was going to make much of a difference as it wasn’t out that much. Well, the rpm is rock solid now. Before PTO engagement in full high speed the tach reads 3750. Once the PTO is engaged the engine reads 3650 and stays within 50 of that point while cutting. After cutting and PTO disengagement the rpm only went up to 3750.

Thanks again for your input, I think I have this issue behind me, and yes, the Tiny Tach may have saved me from future problems.

Regards,

Eric D

Restrorob
07-14-2007, 08:15 PM
Eric, It doesn't take but a fraction to cause a governor to malfunction as you seen. Glad the adjustment solved your problem without having to dive inside the engine.

Cya