JD 317 with Kohler Engine

[eye4iron]

I have a JD 317 with a 2 cyl. kohler engine. It is the updated version with the new oil pump design. (1980s) Anyway, I put new pistons and rings in it about 4 years ago. It was fine until last summer. It started to smoke so bad it would burn your eyes and after about 1/2 hour of mowing I have to stop and put oil in it to continue. I finished the summer with it like that.
The engine probably needs rings and etc. again but before I tear into it I was wondering if the crankcase vent and the little rubber valve inside it could cause the engine to burn oil. Also is it common for this engine to normally blow oil out of the fill tube when you remove the oil cap while the engine is running? I was told this type of engine has positive/negative crankcase pressure. Is this true? Any reply is welcome since the grass is starting to grow.

 

[Rivets]

If this is an OHV engine is suspect a blown head gasket to be your problem. Post some engine numbers please so I can get you a manual.

 

[EngineMan]

The early versions of the suffered from poor lubrication of the connecting rod journals when operated on hill sides. An improved KT17 Series II engine was used starting at engine specification number 24300 in 1982.

KT engines use one of two types of pressurized lubrication systems.

KT series II engines have a full pressure lubrication system, the specification numbers for KT series II models are KT17 series II specifications 24300 and higher, KT17 specifications 24299 and lower. use a pressurized spray lubrication system.

Engine should be a Kohler KT17QS

 

[eye4iron]

My engine is a Kohler KT17QS. The serial number is above 24300. It does not have OHVs. Like I said i'm going to pull the cyl's and look to see where the problem is. I would like to know if the crank case breather vent could be a suspect or should I just go to the heart of the problem. Also, what type of crank case pressure should this engine have when running and the oil fill cap is removed. Thanks.

 

[Fish]

What is the "spec" number?

 

[eye4iron]

I'll try to get the spec number when I take the shrouds off the side of the mower tomorrow. Has anyone else had a crankcase vent problem? Or know if it is normal to blow oil put the fill tube when the engine is running and the cap is taken off?

 

[Rivets]

Oil coming out the vent tube or fill tube is cause by excessive pressure build up in the crankcase. Three main causes of this in an L-head engine are: Leakage passed the rings, Valves not sealing properly, Bad breather. Best way to test for what is causing the problem is a cylinder leak down test. If you don't have this tester, the second best test is a compression test, but this is not very accurate with this problem.

 

[eye4iron]

The spec number is 24301. I pulled the plugs and both had heavy carbon oil deposits on them. Dry not wet. Was there different designs of crankcase vents under the vent cover? I am going to pull the cyls. tomorrow and inspect the rings and measure the cyl.

 

[Rivets]

This manual might help if you don't already have one.

http://www.kohlerengines.com/onlinecatalog/pdf/tp_2043_a.pdf

 

[cashman]

They did have two different designs of the breather assembly used on the later Magnum series engines. One for horizontal shaft engines and one for the vertical shaft MV series engines. The vertical shaft breather was a mirror image of the horizontal breather. The old rubber breather was replaced with the metal reed breather used on the later Magnum series Kohler engines. Try getting a breather assembly for an M-18 model Kohler. Say a spec 24501. I was heavily involved with Kohler working for a Kohler Central Distributor during the time that the JD 317 came out. Not everyone had trouble with the KT series one engines that were spray lubed instead of full pressure lubed like the KT series two and Magnum engines. You had to run those KT engines for about 10 hours before the rings got completely seated in the bores. If you didn't check the oil level for the first 10 hours of use, you probably were running an engine low on oil and yes on a hill side you would starve the engine of oil. I have a 1982 Ariens GT 17 tractor with a KT series one and it's never had any oil problems in the 30 plus years that I've used it. But I did change the breather to the metal reed style several years ago as a precaution.