I have a tractor with a 50 HP Perkins AD4-203 diesel engine with a rough idle. It tends to kind of lope and stumble at idle.

I got the factory service manual from the Massey Ferguson dealer, but it says nothing about how to check the injection timing.

Any suggestions?

I was thinking of trying to do it by ear (turn the injection pump until the idle souds the best).

Any problems with doing that?

What does it idle at? It'll do that if the idle is too low or if there is a small leak in the fuel system. It has a Cav pump right?

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1985 300D Turbo ~225k
2000 F350 (Powerstroke) 4X4, SWB, CC, SRW, 6spd ~148k
1999 International 4900, DT466e (250hp/660 ft/lbs), Allison MD3060 ~73k

Well, I found the timing for the AD3-152 my tractor has and would assume (you know what assuming gets you?) timing should be similar for the 203. It says 20 degrees B.T.D.C. (found that in the owner's manual)

Also this website sells parts for MF and the guys there might have an idea how to time it. http://davistractor.com/ushop/
They were very helpful when I ordered parts from them anyway.

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1985 300D Turbo ~225k
2000 F350 (Powerstroke) 4X4, SWB, CC, SRW, 6spd ~148k
1999 International 4900, DT466e (250hp/660 ft/lbs), Allison MD3060 ~73k

The idle starts getting rough at about 950-1,000 RPM. It will continue to idle below 800 RPM, but it is rough. It has a Cav pump. And I do have at least one fuel leak. The leak comes from the connection for the line that attaches at the front of the pump. I think that is a return line for sending fuel back to the filters(?).

Great. Thank you.

This is a MF 165 right? I think idle should be around 650 although my 3-cylinder 135 idles fine at 500 or even 450 in warmer weather. The first thing I would do is fix that leak before messing with anything else, if it's getting any air in the fuel from the leak that'll cause the rough idle. If you don't have the operator's/owners manual try to find one on ebay, not a lot of info but it's still helpful.

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1985 300D Turbo ~225k
2000 F350 (Powerstroke) 4X4, SWB, CC, SRW, 6spd ~148k
1999 International 4900, DT466e (250hp/660 ft/lbs), Allison MD3060 ~73k

have you checked the basics:
good, water free fuel? clean the fuel system?
tank vent and strainer clear?

don

I don't think there is a strainer and it should have a water seperator so water shouldn't be a concern (these tractors really have overkill as far as fuel filtering). The fuel could be bad but older tractors like that will run on just about anything. It could be injectors getting gunked up but I still would bet air getting in there.

dculkin,

Dump some fuel additive like Powerservice etc. in the tank and see if that improves things.... might either clean stuff up or "improve" the fuel if it's bad.

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1985 300D Turbo ~225k
2000 F350 (Powerstroke) 4X4, SWB, CC, SRW, 6spd ~148k
1999 International 4900, DT466e (250hp/660 ft/lbs), Allison MD3060 ~73k

Yes to all of that except the strainer. I don't know about the strainer, but I seem to get plenty of fuel coming out of the petcock on the bottom of the tank.

I will try that and will try attacking my leak problems and see where that gets me.