Ferris 400S Series RPM

[Skippydiesel]

Update;

Engine starts & runs very nicely. Have managed to increase no load speed to 3300 rpm. Will get some feedback from him after he uses it.

 

[Auto Doc's]

Update;

Engine starts & runs very nicely. Have managed to increase no load speed to 3300 rpm. Will get some feedback from him after he uses it.

 

[Skippydiesel]

After about 2 hrs mowing there are no problems.

 

[LMPPLUS]

My friend has a Ferris 400S Series Zero Turn Mower. Fitted with a new (now 13 hrs) B&S 25 HP, Model 44T977, engine.
He feels that it does not seem to have the power/cut speed of the original 23 HP engine.

I have checked the engine speed:

• No Load is 3060 rpm
• Cutter deck engaged but not cutting grass 2750 rpm.

Does the engine speed, with cutter deck engaged, seem low to you?

Take it back to the dealer and get it addressed and document what happen is case it happens again.

 

[VRR.DYNDNS>BIZ]

Heeelp!

Tried to adjust external governor/lever position - Internal governor position seems to have changed/slipped. Won't return to original position. Engine goes straight to very high rpm. What to do??

Do not run again till a " Static governor adjustment" is performed. then adjust the governed speed to 3600 rpm. I would recommend buying the service manual rather than me describing the adjustment in text but this is the rule: throttle of carb at full wide open and held during adjustment. The solid link to the governor arm then is able to push the governor arm in the same wide open position once the governor arm clamp is lose. Then while all in wide open, in the direction that wide open moves the governor shaft to go wide open, you move the governor shaft in the same direction as far as it will go and feel the hard stop. Clamp in this position and verify throttle can travel fully closed and fully open. then start at min throttle control and increase to max control settings. Find the governor spring adjustment to increase spring tension to increase max rpm at max throttle travel and not be limited by the throttle cable.

 

[TobyU]

Update!
Opened the B&S - governor mechanism in bottom of engine - evidence of overspeed.
Cleaned all the debris using a magnet.
Could not find any other damage.
Replaced governor mechanism using parts from another dead engine (same series).
Reassembled - hope to start tomorrow - wish me luck.

That's what happens when they run to fast. Grenaded governor.
NEVER adjust a governor with engine running or try to adjust or increase speed by loosening and moving gov position.
ALWAYS do static governor adjustment ( throttle plate all the way as far open as it gets and gov shaft all the way it goes when it moves as the throttle is opened) holding both firmly so nothing moves as you tighten gov pinch bolt.
Then you set max speed after you've put cable linkage in proper position by either various (usually color striped) springs or bending tab that spring hold to so it pulls harder on governor arm.

Remember most mowers in the past 15 or so years do not set to 3600.
That is old school. Some do and some even 3700-3800 but not many.
Most are spec'd by machine manufacturer to be 3100-3400.