GT275 Question

nh8260 · Apr 27, 2018

I bought a 1996 JD GT275 lawn tractor back last summer, it has a problem I cannot figure out. When I first start it up, it is full of oil it will puff out a little blue smoke for a few seconds, after 30-45 minutes of running, the oil light will come on first at idle and then it will come on at full throttle. Several times it has even started knocking, I can put in a little oil and its ok for awhile longer. Even after it has knocked, the next day it starts up and runs good again. I checked the compression and it was 100-105 psi. I don't know where the oil could be going, i'm about ready to put another engine (has a Kawasaki 18 hp on it) on it, any ideas or thought would be appreciated, its a great mower and does a really good job.

Janicholson · Apr 27, 2018

If no blue smoke is apparent at the exhaust, it must be leaking. Look under the engine for evidence of washed areas. Any knocking is deadly for the engine. Make sure you are checking the oil level corrently and often. Jim

showcrop · Apr 28, 2018

I have a mower with a 23 HP Kawasaki that does similar to that though not as bad. It does it maybe after every other start for a few seconds. I was told that it is valve seals allowing oil into the combustion chamber from under the valve cover. You had better get new seals into it or stop every 30 minutes to add oil.

DR. EVIL · Apr 28, 2018

Sounds to me like your oil is thinned out with about half gasoline. When did you change oil and filter last?

gtractorfan · Apr 28, 2018

I have a 1998 GT 275 and (knocking on wood) so far it's been flawless. If mine did what yours does I'd take it to a good small engine shop at least to get it analyzed.

russ1 · Apr 28, 2018

Those engines have a crankcase driven fuel pump. If there is any leak in the pump it will inhale it into the crankcase.

W_B · Apr 28, 2018

No help for your issue here but I got a GT275 for use as my primary mower last year. It smokes a bit just after startup but doesn't use any oil. I think the smoke is from an oil leak onto the exhaust. I read somewhere that an oil pan gasket leak is common but a reasonably not hard fix. It was my first JD (ever!) and I like it so well I just got an X300 as a backup mower.

nh8260 · Apr 28, 2018

Oil and filter was changed a couple months ago, not even 10 hours on the mower since changing it

Leroy · Apr 29, 2018

I don't know that unit but what you are describing is the way an overhead valve engine will act if the oil return from the head is getting pluged. It pumps the oil up into the valve cover untill it cannot hold any more and in doing that emptys the crankcase so rod is not getting oil, setting alows the oil in rocker cover to slowly run back into crancase and that is why it is full again the next morning. Adding that bit gets the rod lubing untill that has been pumped into the valve cover and pusfed down around the valve stem and gets burned. Same thing on any car or truck engine. Car I had did have a factory bypass unit on it to drain the rocker cover oil back to crancase And I found out later most of the cars with that engine had that oil bypass line put on instad of tearing engine down to clean out the built in drain back line.

GT275 Question

nh8260

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Janicholson

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showcrop

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DR. EVIL

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gtractorfan

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russ1

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W_B

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nh8260

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Leroy

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