Massey Ferguson 50 Diesel

[cointoss]

I just bought a Massey 50 diesel and can anybody describe the manifold pre-heater? Here in the U.P. of Michigan in the winter I'm having to plug it in to start it and the preheater off the key switch is not working. Looking for a drawing or schematic of the pre-heater to repair or replace.

 

[Jerry/MT]

If it has a fuel supply to it coming off the pump return to tank line than it's most likely a Thermostart unit. It dribbles fuel on a heated grided that is activated by a position on the key switch, basiclly lighting a small flame in the intake manifold that warms the incoming air. In the case of my Ford 4610, it's between the run and start position. You hold it there for 30 seconds or so and then engage the starter. The most common problem with them is the fuel line plugs up, the wire from the key switch is an pen circuit, or the heating grid fails. If a starter switch is replaced, it needs to be replace with one that has a position for the Thermostart wire.
NEVER USE STARTING FLUID WITH A THERMOSTART SYSTEM UNLESS YOU DEACTIVATE THE THERMOSTART. It's been known to blow the manifold off.

 

[cointoss]

Thanks for the reply Jerry now I have an idea about it. There is a position on the ignition key for pre start but I need to check why it is not working. Until I fix it I will just continue to plug it in.

 

[California]

Here's what you need. These are widely available (third party) at Tractor Supply etc under $30.

And here's how the whole system looks. It was an option for Yanmars as well as first used on Perkins engines in MF etc. Different variants were self-refilling via a hose from the injector return line, some Thermostarts had slide-on connectors instead of screw terminals, and I've read there was a version with some odd thread diameter.

 

[The kid]

Thanks for the reply Jerry now I have an idea about it. There is a position on the ignition key for pre start but I need to check why it is not working. Until I fix it I will just continue to plug it in.

Did a quick search on diagrams for MF50 and found this. I use a program in Windows called "Snipping Tool" to cut out images.

View attachment 291071

 

[cointoss]

You guys are the best, thanks!!!

 

[wayacoyote]

This is just what I needed, too. Now that I've found it, how do I troubleshoot it? I've tried feeling around the Thermostart and manifold, neither gets warm. What next/ what else?
Thanks for bringing this up, Cointoss. Thanks for all of the info, everyone else

 

[California]

Verify you have 12 volts reaching the TS when the key is turned to TS.

If this checks ok, replace the TS. I've seen them very inexpensive - around $10 + shipping - on ebay.

 

[wayacoyote]

Thanks, California.
I did that. Voltage checked out. I purchased one online ($20 with shipping). Cranks like a charm!

 

[The kid]

Thanks, California.
I did that. Voltage checked out. I purchased one online ($20 with shipping). Cranks like a charm!

I would just imagine repair shops hate to love us here on TractorByNet. They only get the jobs that are a real bear to deal with. We are glad you got it fixed. Take care -robert