Small Engines (Lawn Mowers, etc.): Bad cylinder valve? bogging down when mower is first engaged. John Deere LA140 model 445577-0110-E1, briggs and stratton, electric clutch

Question
John Deere LA140, running briggs and stratton 23 HP.  Model 445577-0110-E1

I went through the process on a blog from John.  No power to one cylinder (right side).  Replaced fuel filter, plugs, and coil.  Both the coil and the plug have a great spark.  When I pull the left hand side wire from the plug, engine dies.  Also, the right hand plug is "cold" to the touch even after the engine is running for a few minutes.  Seems like fuel is making it to that cylinder, plug is slightly damp, but not saturated.

John was mentioning in a previous blog to another person that the next step might ve the valve on that cylinder.  What am I getting myself into and what is the process and instructions for checking this out?  I have less then 50 hours on this machine and have always babied it.  Yes, I know, this model has issues from a John Deere perspective, but I didn't think I would have any issues with the Briggs and Stratton.  Overall issue is that when I engage the blades, it bogs down so far that it usually dies.  I don't think it is the electric clutch or the spindles, everything is turning smoothly one it gets up to speed.  I have even removed the belt from the clutch to check the mower spindles, everything seems OK.  Appreciate any help you can provide, but once I start tearing into the cylinder, I am going to need some help.  No specs, no diagrams, no torque instructions.  Anything you can do is appreciated, my next step is taking it in, which may be your answer.  Please advise,  Chris

Answer
Hi chris

from what you tell me  it sounds like either you have  coil not firing under compression load  -  ie  engine is running on 1 cylinder and boggs down load exceeding power output
from your description    pulling h/ t lead from r/h side  engine dies - l/h cylinder is not working   make sure the diode  in the kill wire harness is not closed circiut ( these units have 1 diode in each kill lead going to magnetron kill terminal and will lead back to main switch  ) and make sure the carb is clean and clear  and the jets and openings for the l/h cylinder  are not restricted and all emulsion tubes are clear an do rings are good and the fuel pump is keeping up  with demand  ( check its flow from pump to carb  it should be full width of  fuel hose )   make sure that  the plastic manifold o ring on that side is not leaking ( a air leak on the manifold to that cylinder  will affect only that cylinder not both-

start check the carby 1st  , then diode in kill wire system , then o rings on plastic manifold , then check for tight valve clearances ( easy ), then check for leaking valves  ( with leak test ) then  check for blown head gasket.

it is unlikly that you have a faulty magnetron  , but have it tested anyway.

here is web site for parts ipl
http://www.briggsandstratton.com/support/?NTT=445577-0110-e1


ps what happens if you swap the coil  from 1 side to another -? does the fault recreate to the second cylinder or not  ?  it may tell you something.

hope this helps  

paul  

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