Turned up he fuel in my L39

[mike69440]

Turned up he fuel in my L39 about 2 months ago.
It was pretty easy once I removed the anti tamper sleeve on the fuel adjustment screw on the fuel pump. As it is not a turbo and I do not want to roll coal or spike the EGT, I kept it sane to where I see a hint of grey smoke and called it a day.
Tested by running up a hill, same day, fully warmed up.
Stock best speed was 5.1 to 5.2 MPH,
Turned up 5.6 MPH.
Note 2700 RPM is 6.5 MPH in 10th gear, so I was testing near peak power. I can definitely feel the torque increase, though modest.
May not be much but that is going from 37.2 HP net to 41hp.
As I have the L39 ballasted ot over 8,000 lbs, it sure help, still a slow dog, but I think way better.

 

[Harry in Ky]

Okay, pardon my ignorance here. So you turned up the fuel. Can you explain just what did you adjust that had a tamper proof cover? This is where? on the injection pump? On the throttle control? On the governor?

 

[rScotty]

Okay, pardon my ignorance here. So you turned up the fuel. Can you explain just what did you adjust that had a tamper proof cover? This is where? on the injection pump? On the throttle control? On the governor?

I'm curious about the details of exactly how he did that too. It would apply to most of the pre-emissions tractors. BTW, I sure do like those L39 TLBs. A real nice size & wish they still were on the market.

Just musing now.... Since diesels are normally set up to operate way out on the lean side of the stoichiometric ratio, adding more fuel not only richens the mixture, but brings it closer to the max power point - max power being closer to where complete combustion takes place.
Of course max power is also max heat, but it sounds like he is doing it conservatively.
rScotty

 

[Rdrcr]

Congrats on the fuel mod.

Please….Monitor your EGT’s. Do not tune your tractor/engine by sight alone. Most folks are shocked when they learn the temps they’re running after a simple fuel mod when there’s a heavy load on the engine, especially if you’re operating your tractor above sea level.

Mike

 

[Harry in Ky]

I could be wrong here, but I don't think he's in the danger zone just yet. I suspect that what he did was turn the high idle up a bit. Maybe he will come back and explain it a bit more.

 

[mike69440]

I'm curious about the details of exactly how he did that too. It would apply to most of the pre-emissions tractors. BTW, I sure do like those L39 TLBs. A real nice size & wish they still were on the market.

Just musing now.... Since diesels are normally set up to operate way out on the lean side of the stoichiometric ratio, adding more fuel not only richens the mixture, but brings it closer to the max power point - max power being closer to where complete combustion takes place.
Of course max power is also max heat, but it sounds like he is doing it conservatively.
rScotty

A late model L45 is the best without DEF, if you can find one. It and the L39 will outwork most utility tractors doing dirt work. Really.
Look at the fuel pump, Towards the front end of the tractor there is a metal sleeve covering whats looks like a stud. Its crimped om well so good luck taking it off. I used a Dremel an sone tiny pry bars so I could reinstall the mangled sleeve. Underneath there is a adjusting screw and lock nut.
In stock configuration, find a long grade and run up at full throttle in whatever gear gets you at as close to 2700 RPM as possible.

Turn screw out 1/4 Turn and retest. Keep repeating and adding fuel till you see a bit of grey smoke, then quit while you're ahead. If a turbo, definitely install an EGT meter on the exhaust manifold. 1200F after several minutes at full throttle should get max temperature. Temp you should see. A NA motor is hard to hurt, as you can only add so much fuel before rolling coal. Other than plowing snow, My engine load on the L39 is never at the max for long, so I don't worry. I will install an EGT, just out of curiosity. I have never used the PTO or removed the Backhoe. I use the Mahindra for PTO work.
There are a few relatively easy grades that I would have to pull in 10th gear in stock setting. Now adjusted, at least with a head of steam and unloaded, I can pull in 11th gear. Much more satisfying.

Funny how Tractor manufacture's sell the same tractors, with same motor, but different power rating for more money.

 

[Harry in Ky]

Any photos of the mystery screw?

 

[mike69440]

Any photos of the mystery screw?

Tore my rotator cuff 2 days ago, otherwise I would go out and take picture. Spending day resting and one armed.

 

[Harry in Ky]

Never mind about the photo. I see the screw you meant.
Just relax and recuperate.

 

[mike69440]

Never mind about the photo. I see the screw you meant.
Just relax and recuperate.

After I looked up the part diagram already!