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D7 3T pony motor not starting

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1 year 4 weeks ago #248273 by V14
Replied by V14 on topic D7 3T pony motor not starting
Yep, will need to feed it gas for long enough to warm the diesel oil and start it once its off the truck I can get to work on cleaning it out.

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1 year 3 weeks ago #248387 by V14
Replied by V14 on topic D7 3T pony motor not starting
Delivery was once again attempted yesterday. We got the pony running while feeding it fuel but the big motor wouldn't turn. Think that was because I had the pony on idle...anyway dozer is still stuck on this lowboy but the driver left the trailer at my property this time. So since I have pulled the gas tank and cleaned it, now have fresh clean fuel running but the pony still wouldn't run just off that. Just got done cleaning the carb all the jets are now clear and no leftover sediment in the bowl. The float and needle were functioning as they should but I still can't get this thing running on its own. Might have to switch to electric if I can't figure this thing out.
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1 year 3 weeks ago #248388 by ctsnowfighter
Diesel won't turn?
Starting engine won't run above an idle - I believe you do not have adequeate fuel flow.
Pull the tank, pull the lines, if you have any type of filters, change them, ceramic filters were notorious for being plugged, yet look clean.

Diesel won't turn, are you saying it is frozen, locked up, or just the starting engine does not have enough to turn it?
Compression is released on the Diesel?

What prevents you from pulling the cat off the trailer, would not be the first DEAD ONE pulled off a trailer!

Until you solve the fuel delivery system and get the Starting engine running at peak rpm you will gain nothing.

CTS
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1 year 3 weeks ago #248389 by V14
Replied by V14 on topic D7 3T pony motor not starting
Diesel was turning fine almost turned over but not enough out of the pony. I had the advance set for cold weather forgot to put it back so it was running at idle speed. Diesel is not an issue as far as I can tell just needed the pony running at high speed not idle.

Can't get it off the trailer because it's a side load so need to be able to turn it and we tried using my backhoe but it just lifted it off the ground instead. If I can't have it off before he picks up his dozer from up the road we will use that to pull it off but I'd rather get this sorted out.

I agree sounds like a fuel issue but like I said tank is clean no sediment, runs clear after the deep cleaning. Fuel line also clean nothing there and now the carb has been cleaned and there were definitely clogged jets before but now they are clear. I also changed the spark plugs just because might as well. 

I'll add I didn't spend long trying to crank it after cleaning the carb my arm is dead from hours of cranking yesterday. I also still have the air cleaner assembly off not sure how that may or may not affect it.
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1 year 3 weeks ago #248390 by V14
Replied by V14 on topic D7 3T pony motor not starting
Fuel is flowing to the carb as well, if I pull the high speed jet and leave the gas on it flows right through. No leaks or anything from the tank to the carb.
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1 year 3 weeks ago #248391 by juiceman
One bad spark plug can mess you up, or even a bad plug wire. Most pony engines will manage to run on one cylinder, but not enough power to spin the main. JM
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1 year 3 weeks ago #248392 by brian18a
Cleaning the jets does not mean the internal passages are clean. Last resort take the plugs (there a number of them) out of the passages and clean. Can use lead shot to reseal the passages.
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1 year 3 weeks ago #248393 by V14
Replied by V14 on topic D7 3T pony motor not starting
Both spark plugs are new and verified good spark before installing.

I pulled every jet out of the internal and cleaned them as well as the passages carb cleaner had no issues flowing through. There was one at the bottom of the bowl that I couldn't tell where it flowed to I guess that could be the issue but not sure.
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1 year 3 weeks ago #248395 by ctsnowfighter
I am still betting on dirt, debris, sediment in the carb body -- assuming you have 1/4" line running full stream to the float bowl.

We had a 9G D7 that sat for years, had gas in the tank for starting engine --- Cleaning the fuel tank valve, the sediment bowl, pulling the line to the carburetor allowed enough fuel to keep the starting engine running at half choke. Not ideal set up - BUT - the Diesel started right up -- they do not have to turn fast, just be warm enough to ignite the fuel injected.
Removing the carburetor, cleaning and ensuring float level and needle/seat were correct - it always fired right up.

AS JM said, one faulty wire, plug can make a major difference. Sounds like you have that sorted out.

What are you speaking of - advance set for cold weather?
Are you talking of the gear box on the starting engine to the main?
If you have the Diesel turning and it is warm enough to ignite the fuel injected into the cylinder, you will get some sort of action. Smoke, at least --- white is COLD!

Not sure where you are based for home, here in N. Ca Sac Valley, I never used Low Gear on any starting engine. Always High and turn the diesel with compression released until you have oil and fuel pressure. Go to "full" compression, wait a short time and then throw the fuel to it, It should fire right off.

If you leave fuel on during the warm up process, you can end up washing the lube from cylinders and compounding your start problems.

Cranking till your arm gave out? If it does not start or at least fire in a few pulls of the crank, chances are you are not going to start it if you pull on the crank all day long!

When they are right, they start, and as many here say, those engines know when to act up and they do!

Dad - a mechanic all his life, and trained as Deisel Mechanic in WW II. One of his rules "when you are POSITIVE it is Gas (fuel) problem will be ignition, same in reverse"
That Rule WORKS!
CTS
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1 year 3 weeks ago #248396 by V14
Replied by V14 on topic D7 3T pony motor not starting
Manual spark lever is what I was thinking not advance...it has to be fuel no other potential problem if I'm getting spark. Of course I wouldn't normally crank for hours just had to try as much as possible to get this thing off the guys trailer.

I was trying to start it in low not high compression, fuel off pinion engaged clutch in and got the white smoke, waited a bit to warm it and threw it into run got a couple coughs of dark smoke but with the pony at idle speed it wouldnt and probably being on low it wouldn't work. This was an issue because we were manually feeding fuel into the carb while trying to turn the diesel and ran out of gas while trying to turn the diesel. After that couldn't get the pony started again.

I'll just try and pull the carb again tomorrow after work and run through it again. Since i cant keep it running at idle or full speed chocke/half/none i don't even have a lead on what may be clogged, certainly frustrating.
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