# Adding horsepower to TC-18 New Holland compact tractor



## gman51 (Mar 22, 2016)

I have a New Holland TC-18 compact tractor and I want to raise horsepower from stock 18hp to 25hp. The engine is a diesel three cylinder with 18 stock horsepower.
I have heard the injection pump can be turned up so it is putting out more fuel for more HP. I am guessing perhaps the only difference between an 18hp TC tractor and a 25hp TC tractor is probably the fuel pump calibration. I am guessing the engines are basically the same.
The reason I want more horsepower is because in thick grass even only 8" high mowing with a 3.5 - 4" shredder the engine boggs down from the marked 2500 rpm down to maybe 1300 rpm. This cause the engine to run a bit over center on temp gauge.
I have a Cub Cadet 1550 52" deck with a 25hp engine and it seldom boggs down in the same conditions. This TC-18hp just isn't enough horsepower in my opinion.

Can anyone tell me if or how I can turn up the injection pump and can the engine take it without causing excessive wear on it? I still believe the TC-18 3cyl and the TC-25 3 cyl. use the same block and compact tractor assembly.


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## thepumpguysc (Jan 25, 2015)

The adj. is either infront or behind the inj, pump.. it will have a cap & safety wire on it..
The screw is actually a 2pc screw.. U want to turn the WHOLE assembly..
U turn it OUT.. PAY ATTENTION how much u turn it.. 1/4, 1/2, 1 full..
THAT WAY u can turn it back if not happy..
I would go 1/2 & try it.. 1/2 more & u got A LOT of smoke.. turn it back IN 1/4..
Heavy BLACK smoke means to much fuel & not enough air..& the excess fuel will be washing down the cylinders..


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## gman51 (Mar 22, 2016)

I talked to a man up the road that repairs heavy equipment about it and he said he could get 5 to 6 more HP by adjusting the pump plate, fuel delivery and timing. I said that would be good.
He said he could get a lot more by changing to bigger injectors and head work so it wouldn't blow a head gasket. I said no to that.
He asked when I last had it serviced and I said a few years ago but I hadn't put many hours on it since then. I did keep he engine oil serviced.
I decided to check the air filter to see how bad it was. Geeze the filter had the hours marked on it when it was changed. Holy crap the hour meter had over 200 more hours on it. I pulled the filter and it was really filthy black. I checked the inlet hose and it was 3/4 blocked by a wasp mud nest. I even found a smaller mud blob inside the housing.
No wonder the engine was bogging down! It couldn't breath for squat.
I replaced the air filter and geeze average cost was around $65. I got one for $41. I found one on the internet for $23 but I needed one today.
I noticed the engine had more power now. Imagine that! 
I still took it to have the HP bumped some.


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## thepumpguysc (Jan 25, 2015)

Turning it up is a DIY job.. 10 minutes max.. The hardest part would be finding the wrenchs to fit it.!!!


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## gman51 (Mar 22, 2016)

Well the guy up the road was a bust. Just shy of a week I don't think he even touched it. I went to check on it and it was right where I left it.
The side cover wasn't opened out of the way. The hood was still up as I left it and nothing looked like it was touched. He said he started on it but kept being interrupted but he would finish it that afternoon.
I called the next morning and of course for the second time he let it go to voice mail. Funny how he answered my calls before taking it to him. I left message I was coming after it since he said he would have it done. I said done or not I was coming to get it.

I got there and of course he wasn't there but his truck was there. I figured he was in the house and didn't want to talk to me.
I told his employee I came to get my tractor. He didn't seem surprised. The tractor still hadn't been moved or side cover out of the way. The hood was still up like I left it.

His employee called him and he said he tried to adjust it but it was either to much or to little so he set it back where it was. He said let me take it. I asked his emplyee what did I owe him and he called him back asking what was the bill. He told his employee no charge.
I am willing to bet he didn't do squat to it which is why no charge.

I got it home and mowed with it and I didn't notice any difference in how much power it had. The grass is fairly dense now and the 18hp boggs down 500-700 rpm in the really dense areas. In other words no noticeable difference.

Pumpguy where is the adjustment screw you talk about? I have just about any size/type hand tool. Metric and standard. I guess I need find a picture showing the pump payout of the screw because I don't see any screw/bolt by itself.


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## thepumpguysc (Jan 25, 2015)

Click on my screen name on the left hand side of the page.. THAT will give u my contact info..
Snap a pic of the engine A GOOD PIC & send it to my home email address.. its easier than posting here.. I'll point out the fuel screw..
Its going to be/usually be, on the radiator side of the engine, directly inline w/ the inj. pump.. it prob has a tamperproof cap on it..??


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## gman51 (Mar 22, 2016)

I took some pics. There is a hollow cardboard tube that can be turned and there is another piece below that which looks like maybe a screw or bolt with a cover. These pieces are located lower back toward driver.


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