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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 26029
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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I have a 1996 John Deere 425 with a 20hp Kawasaki fd620d motor

Customer Question

I have a 1996 John Deere 425 with a 20hp Kawasaki fd620d motor in it. The left side glows red in about 20 to 30 seconds. I have adjusted valves to factory specs .010 and also tried it at .008 no change. I have cleaned the carb as well.
Submitted: 7 months ago.
Category: Small Engine
Expert:  Curtis B. replied 7 months ago.
Do a cylinder balance test, loosen the spark plug wires and with engine idling, remove one wire at a time, engine should continue to run If engine dies when either wire is removed, the opposite cylinder is not firing. You may find that the left side is carrying all the load!
Customer: replied 7 months ago.
Already did that the motor runs on both sides no big change in sound except you removed a plug
Expert:  Curtis B. replied 7 months ago.
Exhaust restriction the left side?
Customer: replied 7 months ago.
Had exhaust off no holes in it or anything inside it
Expert:  Curtis B. replied 7 months ago.
Right side no where close to being as hot? Carburetor feeds common manifold, both sides firing, exhaust clear, this is water cooled engine, do you water in the left head?
Customer: replied 7 months ago.
Yes it is water cooled thermostat on that side get warm at hose assuming water going through head
Expert:  Curtis B. replied 7 months ago.
Remove the thermostat , reinstall thermostat housing , refill and test run, and see if left side still heats.
Customer: replied 7 months ago.
OK. But both hose top and bottom gets warm assuming it works a car that should mean it opening right
Expert:  Curtis B. replied 7 months ago.
How do you spell assume? I would try it , less thermostat.
Customer: replied 7 months ago.
OK anything other ideas you think I could try
Expert:  Curtis B. replied 7 months ago.
No, I think you have air trapped in the left side.
Customer: replied 7 months ago.
OK how do we get rid of it. To the best of my knowledge no one ever drained the water out to cause on air pocket in that head.
Expert:  Curtis B. replied 7 months ago.
Bleeding is only mentioned in service manual by running and letting thermostat open and then top up the radiator. I would want to remove the thermostat and with radiator filled, run engine and see if the coolant is circulating. No circulation, water pump is not moving the coolant. Also on the side of the water pump is a vent line, that has to be open for system to vent properly.
Customer: replied 7 months ago.
OK I did put a governor gear in it and checked water pump gear is good hole on bottom is open. Was not leaking.Had exhaust problem before fixing governer gear.
Expert:  Curtis B. replied 7 months ago.
Was water pump impeller checked?
Expert:  Curtis B. replied 7 months ago.
OK, getting too late for this old man. try removing the thermostat, and we can go from there. Good noght
Customer: replied 7 months ago.
OK thank you for your help I'll give it a shot
Expert:  Curtis B. replied 7 months ago.
OK< Let me know!
Customer: replied 7 months ago.
Hello again Curtis. Todd I talked to you two days ago. I have a 425 John Deere with left exhaust glowing red. You wanted me to remove thermostat and refill. I tried that and no change in exhaust. Still glows red in about 15 to 20 seconds. Do you have another idea I can try. Sorry it to so long but something came up last night and I could not get back to you. I sure could use more help please.
Expert:  Curtis B. replied 7 months ago.
You ran it without thermostat?
Customer: replied 7 months ago.
Yes
Expert:  Curtis B. replied 7 months ago.
I have never seen this on an engine that was running on both cylinders, only when engine was running on the hot cylinder. You said you ran cylinder test.. How hot does the right exhaust get?
Customer: replied 7 months ago.
Tried a compression test on both cylinders numbers were about 140 to 150 in both cylinders. Also unhooked one plug at a time run about the same. Right exhaust looks fine no glow
Expert:  Curtis B. replied 7 months ago.
oK> I have nothing else to try. Let me opt out and see if anyone else can come up with idea! Sorry.
Customer: replied 7 months ago.
OK thanks