Governor question

arch252

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I have a Kawi FD501V twin cylinder liquid cooled on a JD LX279. I've had to replace a number of things, to include the carb. It was running very rough and the jets were seized inside and I ruined the jets getting them out so I replaced the carb. I've replaced the voltage regulator that was bad (not charging). New PTO also. Engine RPM's were not an issue before.
Now when I engage the PTO it drops about 1000 rpm. It will also struggle when going uphill, the governor is not compensating. I have reset the governor correctly. I'm afraid I may have stretched the governor spring slightly during the carb replacement.
Could a weak governor spring be the cause of the governor not compensating for the power draw and causing the RPM's to drop? Is there anything else I should be looking at?
 

bertsmobile1

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Yes
The speed is a tug of war between the governor which is trying to close the throttle & the governor spring which is trying to hold the throttle open .
Pull the governor arm to open the throttle slowly with you finger
If you feel the arm pulling against your finger and it gets stronger the faster the engine is reving then the governor is working properly
 

geelee

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the governor is built onto the cam, it uses large ball bearings in a flyweight system. the part that spaces the balls is made out of plastic, it locks onto the cam with 2 small tabs, if they break off the governor will work but with a long delay.
 

arch252

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I have another LX279 that I use regularly. I swapped the governor springs and there is no change. The mower runs excellent, starts easy and idles good up and down. It has no issues until you engage the PTO or drive it up an incline and then the RPM's drop significantly. What else could the issue be?
 

hlw49

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the governor is built onto the cam, it uses large ball bearings in a flyweight system. the part that spaces the balls is made out of plastic, it locks onto the cam with 2 small tabs, if they break off the governor will work but with a long delay.
Does not look like the engine I pulled up. Governor looks like a Briggs or Kohler.
 

hlw49

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What is the top no load speed? Service manual say 3550. Did you take the throttle control plate loose or off? If you did and did not put it back exactly where it came off it will effect the top no load speed. Changing the spring would have no effect if this is the case.
 

arch252

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I did have to take the throttle plate off when removing the carb. When I put it back on I adjusted the plate to roughly 3600 rpm and tightened it well. The plate has not moved and it holds the correct rpm at high throttle, until I engage the PTO or travel up an incline, then rpm's drop to about 2400.
 

hlw49

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Have you done a cylinder balance test? Start it up and pull one plug at a time and watch the drop in rpms and if it dies on one cylinder the other one is dead. 1000 rpms is a big drop with both cylinders firing but not just firing on one.
 

arch252

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I have put a spark tester on each cylinder while running and when it's under load, both show a steady spark.
 

hlw49

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May not be a spark issue very carefully feel the exhaust pipe going into the muffler if one is not firing it will be cool but be careful not to burn yourself.
 
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