MF 135 Perkins Gas 3 Cylinder Backfiring no Power

ultrarunner · Dec 7, 2023

Whiteout or White nail polish works great for witness marks.

slhilbert · Dec 7, 2023

I went out and put my hands on stuff and I am starting to get it. I looked through my parts and I believe I am missing one part and working on getting the shaft, I don't think I ever have it and it could be why this whole issues happened in the first place.

In the picture below I am missing the highlighted part.

The AGCO Website shows the part and part number under Perkins (Gas) and there are two pictures, both with the same picture

Looking at the shop manual the only place I find an entry for the Woodruff Key is for the Continental Gas 165

Do I order it then? If I do, how to I use it?

Thank You!
Stuart

etpm · Dec 8, 2023

slhilbert said:
I went out and put my hands on stuff and I am starting to get it. I looked through my parts and I believe I am missing one part and working on getting the shaft, I don't think I ever have it and it could be why this whole issues happened in the first place.

In the picture below I am missing the highlighted part.
View attachment 836090

The AGCO Website shows the part and part number under Perkins (Gas) and there are two pictures, both with the same picture
View attachment 836108
View attachment 836096
View attachment 836098

Looking at the shop manual the only place I find an entry for the Woodruff Key is for the Continental Gas 165
View attachment 836105

Do I order it then? If I do, how to I use it?

Thank You!

slhilbert said:
I went out and put my hands on stuff and I am starting to get it. I looked through my parts and I believe I am missing one part and working on getting the shaft, I don't think I ever have it and it could be why this whole issues happened in the first place.

In the picture below I am missing the highlighted part.
View attachment 836090

The AGCO Website shows the part and part number under Perkins (Gas) and there are two pictures, both with the same picture
View attachment 836108
View attachment 836096
View attachment 836098

Looking at the shop manual the only place I find an entry for the Woodruff Key is for the Continental Gas 165
View attachment 836105

Do I order it then? If I do, how to I use it?

Thank You!
Stuart

Well, if you are missing a woodruff key then you are in luck. They are a standard item available at any good hardware store. In case you are not familiar with them they are basically a half moon shape. Because they were standardized decades ago there should be no problem getting the one that fits your shaft. Also, because the sizes were standardized you can bring your shaft to the hardware store or good auto parts store and easily find the proper sized one. It will fit snugly in the slot if the slot is not worn. It will protrude above the shaft about the same as the thickness of the key. It should fill the slot and not slide back and forth. It will rock in the slot because it is circular in shape.
Eric

DJ54 · Dec 8, 2023

According to the AGO parts book the woodruff key part number and size is 2957X (1/8 x 1/2" Woodruff) (Perkins No. 0500003) Local dealer shows the price of $4.29.

Personally, don't know that I'd get one from a dealer, but neither would I get one from a local hardware. The tensile strength varies so much on these I'd much rather spend a couple bucks for one through NAPA then to have the same problem again. An 1/8" key isn't very thick so I'd opt for one from NAPA etc.

I'd look for, or if you know the person behind the counter has a little knowledge/experience, that's the one I'd go to, and tell him/them what it's for. If they have different grades of them, they should be able to get you the correct one. JMO, take it for what it's worth.

ScipioUSA · Dec 8, 2023

slhilbert said:
I went out and put my hands on stuff and I am starting to get it. I looked through my parts and I believe I am missing one part and working on getting the shaft, I don't think I ever have it and it could be why this whole issues happened in the first place.

In the picture below I am missing the highlighted part.
View attachment 836090

The AGCO Website shows the part and part number under Perkins (Gas) and there are two pictures, both with the same picture
View attachment 836108
View attachment 836096
View attachment 836098

Looking at the shop manual the only place I find an entry for the Woodruff Key is for the Continental Gas 165
View attachment 836105

Do I order it then? If I do, how to I use it?

Thank You!
Stuart

If you look at your video on page 6 where you finally got the shaft out, it looks like the key is still in the shaft. It should fit into a slot in the timing gear. Take another look at your old shaft and see if it's in there still.

If the new shaft doesn't have a key when you get it, you can get one at any number of places as already mentioned.

RE: finding top dead center, remember the piston is at the top for both a compression stroke and an exhaust stroke. It's possible to be 180 degrees off, so take your time and double check.

Glad it looks like you can start to turn a corner!

MRTOES · Dec 8, 2023

big bubba said:
plugs, pts, ign wires as well. though feel it could well be fuel quality related if the machine was running fine months ago, good luck

Since its gas and old enough to have points you have a condenser....(all do even the new ones.....in some form or another)..Replace it. You said the tractor sat for a while. The condenser keeps the back flow from happening every time the points turns the coil off or on.
I learned the hard way long time ago messing with one and blew the muffler off a car.

pmsmechanic · Dec 8, 2023

ScipioUSA said:
RE: finding top dead center, remember the piston is at the top for both a compression stroke and an exhaust stroke. It's possible to be 180 degrees off, so take your time and double check.

But the exhaust stroke won't push your finger out of the spark plug hole. See post #70.

ScipioUSA · Dec 9, 2023

pmsmechanic said:
But the exhaust stroke won't push your finger out of the spark plug hole. See post #70.

Very good point! I was more thinking if he was just using the screwdriver to watch the motion of the piston, it would be possible to get out of phase.

slhilbert · Jan 8, 2024

Well, it took about 22 hours of work and I might have put things on and taken them off more than three times, but she is all back together and working. Pushed some snow on Saturday even! Thanks to all of you for all the help! I couldn't have done it with you all.

Stuart