1978 Case 446 Problem

[DonS]

My 1978 Case 446 stalls and backfires when mowing. It seems like it gets really hot. Once it stalls I have to let it sit awhile before the starter can turn it over. The deck bearings are ok, spark plugs have been replaced. I always keep the motor and the radiator clean. any ideas? I've owned this tractor for 15 years and never had to do any repairs on it except for the deck.

 

[blackjack]

Have started using a different type of gas lately? I remember having a similar problem with my dad's 448 and it was because the gas we put in contained ethenol.

 

[denm]

owners manual says at every 400 hours of operation to pull heads and clean away all carbon deposits

 

[ducksjunk]

Don;
Had similar story with 220. Over time the high speed adjuster seems to vibrate in, creating a lean condition. this will result in backfire and overheating. Try opening it up until the rpm just start to drop slighly, this will give you more fuel under power , and the extra fuel helps to cool the engine.
Richard.