Engine smoking

[Rob01]

I have a John Deere 345 mower with a 54 in. deck (95 or 96 year model), with an 18hp kawasaki motor. I started getting excessive smoking everytime I start it up. This got worse each use till I had to do something to find the cause. I found that the valve covers were melted on the bottom, these seem to be made of some sort of high temp plastic. I replaced the valve covers only to melt the new ones. The exhaust pipes going to the muffler are directly below these covers so I took the muffler off to see if it was clogged causing excessive heat, but no problems were found. I'm a bit stumped about what's going on now, any help would be appreciated.

 

[motoman]

Robo, Pros will respond I am sure. Seals on valve guides? Read plug color. Compression check. White smoke? Head temp at gasket read with infra red gun or temp probe on a good digital volt meter. (suggestions)

 

[7394]

Did you remove the cylinder covers to make sure the cooling fins are NOT clogged up with yard cuttings ? This will cause an overheating issue..

And should be part of regular maintence..

 

[exotion]

Cleanliness does play a huge factor in air cooled engines. That's a good start tear down all the covers and such and clean everything on the engine.

Next I would see if your valves are adjusted to factory specs, this happened to my briggs Intek

 

[Rob01]

I will check the valve clearances, but it's a liquid cooled engine so no clogging of cooling fins. Thanks for the responses.