Hood open/closed?

[TLD89]

When tilling when the temperature is over 99 deg. should I leave the hood down or will it help cool the engine with the hood up?

TLD89

[DavidBarkey]

When tilling when the temperature is over 99 deg. should I leave the hood down or will it help cool the engine with the hood up?

TLD89

That would depend on what model you are using . My experience is the under hood muffler models benefit from having the hood off , but the external mounted muffler models seem to benefit from hood in place due to air flow over the engine from cooler fan . The most important things are cooler fan in good condition and clean cooler fins . As well as engine fan screen and fins are clean .

[myerslawnandgarden]

I fully agree with Dave on this one. In 1976, the muffler was moved under the hood on the 3 digit tractors which raised the underhood temperature a good amount. So much, in fact that we began to see Kohler engines coming in for rebuild at 300-400 hours instead of 1000 or so previously. In addition to the higher ambient temperature under the hood, remember that the muffler was directly above the engine's cooling air intake so in effect, you were trying to cool the engine with hot air.

In the late 80's, the trend from the engine and equipment manufactures was toward longer warranties instead of the traditional one year period. Both Kohler and Onan refused to give Ingersoll the two year warranty due to their high operating temperature.

That's the reason for the 1989 redesign and introduction of the 4 digit tractors as in order to be competitive with the other brands, the same warranty was needed and Ingersoll did not want to foot the bill for the second year out of their pocket. This also addressed the age old complaint of excessive heat on the operator and offered a simple way to add an electric clutch as shorter blade stop times had also been mandated by the safety organizations.

Otherwise, it's doubtful that there would have ever been such a major redesign, especially one the made most of the previous attachments obsolete.

Just some insight,

Bob

[MattA]

Good info Bob. Always wondered why the engines were rotated 180° on later model tractors.

[DavidBarkey]

Both of my 446 tractor have had there muffler relocated to outside the hood . Frankie has a old school stack and the blower tractor has a pair of machine gun style muffs . Both reduced under hood heat dramatically and directed exhaust away from coming in the cabs .

[Seabee]

The redesign did introduce some nice features, but most of them could have been done with the old design. Getting the heat out of the drivers face was probably the best. I love all of them, still spend most of my time mowing with my 448. I have my 4020 totally torn apart redoing it like I did my 4118.

My 4118 is for sale in the meantime! I will see if I can get a picture of it to post. I will make a separate post in the next few days.

I lost my password and for some reason it turned out to be more hassle then I was willing to go to at the time. Obviously I got it taken care of tonight! I missed some of the information exchange that I was looking for.

Thank you for all the posting you have done in the meantime. I have lots of good reading to catch up on! Thanks!

Bill

[ssmewing]

I like the history part from Bob.

Other than keeping your engine clean from oil, keeping the cooling fins unpainted and clear will help. The tins are all 100% needed.

Then the timing needs to be correct. When the timing is off, it will still run, but not optimally. I had a horrible time with the points on a 644. I kept having the timing change when I re-tightened the adjust screw, and then the way the timing is changed on Kohlers sucks. The 644 technically was the challenge. The tower was next to the points and prevented access from the side. The engine was otherwise a fresh rebuild by me. But, when the timing was off, the engine was hard to start, and it was running hot, and it would not run right if I was not working it enough to get the governor working well. I added a flat washer to the points adjuster screw, and then I finally had no more overheating.

The other way you run hot is a dirty carb, or more importantly, a lack of proper fuel metering. The fuel system is not just the carb. It is everything between the gas cap to the fuel charge in the combustion chamber.

I finally have Rec Gas at the grocery store I go to. There is finally a fuel for sale that has the cleaning additives that fuel had way back in the 90s. It is sold at stations that decide to have it. It is called Top Tier fuel. You can go to their website to find out if it is near you.