QuestionQUESTION: On a John Deere GX75 rear engine riding mower.
Is there something I can do about the engine that smokes quite a bit? It starts and runs and mows good, even blows a bags just fine, with the rear bagger apparatus on.
Here's the deal. It's a Kawasaki 9HP K Series Code:FC290U-CS10
E/No: FC290U166432
This mower was given to me and I am giving this lucky machine all the TLC I can. (I'm loving a rider at this price :))
I have done the following: New battery, New belts, Changed Oil, Sharpened blade, took the gas tank off and cleaned it well(it had floaties in it), replaced gas line and gas filter, sprayed carburetor cleaner in, a little, ran some injector cleaner through it(poured a little in the tank). Drained the tank and changed gas since then(New gas). Still smokes. Cleaned this machine and it looks nice. Adjusted the brakes and seat and shined her up!
PS. Also would like to replace the Quadrant(Shroud) covers.
Left and right PT# AM116147. From John Deere site.
Center PT# AM115960. From John Deere site.
Can't find those.
Thanks for any help.
Roger
ANSWER: Hey Roger...
IS the smoke, Black/Blue or white? Is the engine over filled with Oil? Is the air filter clean? Does it smoke more when its under load? meaning when your using it. Does it seem to lose power when it starts to smoke?
To rule out the air cleaner as a problem simply remove it and start the engine to see if the smoking goes away?
What Weight Oil is in the engine? Stick with SAE 30 or 10W30
IF the smoking continues, it may be the crankcase breather valve located in the cylinder head, the Valve seals could be bad, a head gasket could be blown, bad valves, or worse yet cylinder rings. Now having said that this stuff is all repairable with a little know how.
As far as the parts go, have you checked with a local John Deere dealer in your area?
So in closing:
Check to be sure Oil is NOT overfilled.
Remove Air Filter and see if smoke goes away. IF it does, get new filter!
Get back to me with color of smoke and i can instruct you further.
Dave R
---------- FOLLOW-UP ----------
QUESTION: David: The smoke is white - definitely.
Smoke does not change with the air cleaner removed. Also air filter looks clean and new.
Engine oil level is right. I checked it again before starting this time. Oil is Pennzoil 10W-30W.
The smoke is present right from start up,thins out a little after warm up, the amount of smoke does vary some.
I do not sense a loss of power with smoke variations, nor can I say the smoke gets thicker with load.
The load I tried to sense was engaging the blade in a stand still situation.
ANSWER: Alrighty then... You may not be able to diagnose this without proper tools, but I will give you a couple of other areas to look, but i think its unlikely that they will be the culprit.
Check the o-ring(s) on the oil dipstick, make sure that is making a proper seal.
Check Head assembly bolts to make sure they are tight.
IF you dare remove the Valve cover and look to the upper left hand side you will see a little reed valve, It is covered by a plate-held on with a single screw- make sure that this is not distorted, broken, warped etc... this may be the problem. Do you have oil consumption when using the engine?
If I was trouble shooting the unit I would perform a leakdown test. This means I would introduce air through the spark plug hole with a special meter that would tell me if valves, valve guides, rings etc were okay.If there were a bad head gasket I would know immediately as I would hear the leakage and see pressure lost on the meter.
IF the obvious things i told you to look at are not a problem, you could remove the head and inspect the valves and valve guides, perhaps the rings...and most importantly the Head Gasket.
Hang in there we will get this figured out!
---------- FOLLOW-UP ----------
QUESTION: I'll proceed with these things. And get back with you this week. I may just be able to get a leak down test done myself with a hand pump, or I have a little 12V air pump. We're only talking about 20-30 PSI or so huh? That would tell a story to the trained observer. That would be you. :)
AnswerRoger,
It will take more air pressure then 20-30 psi. I would strongly suggest unless you have a strong knowledge of 4 cycle theory you leave this test to the pros... I say this because you need to have the test on a certain stroke, if its in the wrong position, ie the intake stroke you will have air leaking through the carb, but this will not be the actual problem... exhaust stroke... noise in the muffler etc...
I would encourage you to do a compression test on the engine first and then proceed with the removal of the cylinder head to check the gasket and the reed valve. Unless you have an actual leakdown tester you will not be able to do an accurate leakdown test.
