CH23 bogs down and dies when engaging pto

[Hammermechanicman]

Curious. Are you engaging pto at idle or full throttle? My Ferris 3100Z manual says to engage at full throttle. I have worked on mowers with big decks that you had to engage at near full throttle or the engine would bog down. My 184 LoBoy will kill the engine unless i have engine warmed up and at near full throttle.

 

[cpurvis]

People regularly set them up backwards because they forget the governor WORK to slow the engine down not speed the engine up.

Have to disagree with this statement. Governors work to maintain an rpm, whether than means slowing down or speeding up.

 

[Hammermechanicman]

Kinda of a semantics thing. A small engine centrifugal governor does control the engine speed according to load but it does it by acting against spring tension to slow the engine to a balance point. Spring tension speeds it up, govenor works to slow it down. Semantics, it is just a generally misunderstood and misadjusted system. Philosophical $0.02 for the day.

 

[cpurvis]

Gotcha.

Bert, please disregard my comment.

 

[mackmanj1]

Curious. Are you engaging pto at idle or full throttle? My Ferris 3100Z manual says to engage at full throttle. I have worked on mowers with big decks that you had to engage at near full throttle or the engine would bog down. My 184 LoBoy will kill the engine unless i have engine warmed up and at near full throttle.

Deck's engaged at full throttle. The only way to get it to engage and stay running now is to set the choke half on, engage the deck, then push the choke off.

 

[Hammermechanicman]

If you have good compression (?) with no leaking head gaskets and good spark on both cylinders are you sure the engine is not running slightly lean? Have you cleaned the carb and checked the main jet?

 

[mackmanj1]

If you have good compression (?) with no leaking head gaskets and good spark on both cylinders are you sure the engine is not running slightly lean? Have you cleaned the carb and checked the main jet?

I've had the carburetor apart cleaned, wire ran thru every hole possible to run thru, at least 4 times. Soaked in carb dip each time. Did the same with main jet and mixer tube also. New kit installed again on last teardown.

 

[mackmanj1]

Had something interesting yesterday while putting carburetor back on. While I was installing I broke the ear off the insert where the choke linkage attaches to carburetor. Since I was "down" until parts to repair the choke came in I decided to play with the jetting. Keihein main jets in motorcycle carbs are the same as the one in this carb. I put 2 different bigger size jets in and it made absolutely no change in the way the engine ran. Expecting the bigger jets to cause the engine to load up with fuel and run rich it didnt happen. I took an unmarked jet and drilled it out to 1/16" installed it and it still made no difference. The only way to get the engine to load up with fuel and puff black smoke is to choke it. Im beginning to think I still have a restriction in the high speed circuit. Sounds like a new carb might be needed.

 

[bertsmobile1]

Had something interesting yesterday while putting carburetor back on. While I was installing I broke the ear off the insert where the choke linkage attaches to carburetor. Since I was "down" until parts to repair the choke came in I decided to play with the jetting. Keihein main jets in motorcycle carbs are the same as the one in this carb. I put 2 different bigger size jets in and it made absolutely no change in the way the engine ran. Expecting the bigger jets to cause the engine to load up with fuel and run rich it didnt happen. I took an unmarked jet and drilled it out to 1/16" installed it and it still made no difference. The only way to get the engine to load up with fuel and puff black smoke is to choke it. Im beginning to think I still have a restriction in the high speed circuit. Sounds like a new carb might be needed.

Unless you grabbed the throttle linkage from the governor to open the throttle butterfly then you are just running on the idle jet, not the main jet so changing it will have no effect.
I have ridden a motorcycle for 10 days with no main jet at all ( accidently got tossed away ) and the bike ran fine up to 3/4 throttle because the needle jet is the limiting factor not the main jet.