314-8 GT starting issues

[RusTia 5]

Hi all, I stumbled across this forum while trying to diagnose an issue with a 314-8 GT my dad handed down to me when he bought a new one this past spring. He purchased it in August, 1997 and it has been used for general yard work and lawn mowing. It has had a great life so far with no major issues until late last summer when all of a sudden it would not start.

 

The engine would turn, but not fire up. After some playing around with the carb, I determined that it was not getting fuel when trying to start. However, I would just manually add fuel to the bowl to start it, and it would start right up. Once it started, it got fuel no problem and would run great for hours while cutting grass. A week would go by and I would have to do the same manual adding of fuel to get it to start, but it would run fine again. This went on all summer as I had no time to really look at it. I just assumed it had something to do with the ignition system not activating the fuel pump, but once it turned over, the fuel pump worked as designed.

 

Then one day toward the end of the summer, I turned the key and nothing. No crank at all. The battery is still good and the lights on the panel would light up, but the engine would not turn or even make a sound.

 

In searching the forum, I think I have narrowed it down to ignition module, starter, or solenoid. However, I don't want to order parts that I may not need so I am hoping to get some experienced guidance. My thoughts are that the two issues described above are related. Perhaps the fuel issues in the middle of the summer were symptoms of a part going bad, but still able to limp along. The final issue of not starting was when the part finally gave out. Or, perhaps they are not related and I have multiple things to look into.

 

I would greatly appreciate any information and/or advice. If this is in the wrong forum, I apologize. I thought it would go best in the engine since I am not entirely sure what the issue is.

[Jerry77 1,218]

 to red square.............

 

The first part sounds like a weak fuel pump - tank is under the seat and it takes a bit to get the fuel to the carb - had the same problem and put an electric pump on...problem solved..however...it could be something else entirely..others will chime in..  it won't turn over if the safety switches aren't made - make sure the pto is disengaged when starting ( has a seat switch too )

 

 

Edited February 9, 2017 by Jerry77

[SylvanLakeWH 25,926]

 

Electrical issue - I would start by checking every fuse. (Son just blew one plowing the other night). Check all connections for shorts. Fuel issue - Agree with Jerry77 about fuel delivery. Would also check fuel line and filter. Take hose off at carb and see if you are getting gas through the line to the carb.

 

[953 nut 55,767]

  The two problems are not related. An electric fuel pump mounted low on the frame will fix the fuel issue. Put in a new filter and fuel line too.

The wiring diagram in this manual should help. With any electrical problem you should always start by cleaning and tightening all connections including grounds.

 

[gwest_ca-(File Mod) 11,095]

Model number 73400 or 73402 off the decal under the left side of the seat would help. Plus a 59xxxxx, 69xxxxx or 79xxxxx serial number is 1995, 1996 and 1997 respectively.

The ignition is self-powered and seldom fails. The ignition is shorted to ground to shut the engine off so that is how the safety switches function. One half of the pto switch and clutch pedal switch control the starter circuit. The other half of the pto switch and the seat switch control the ignition.

You most likely have two unrelated problems. Will look for wiring diagrams after the numbers are determined.

 

Garry

[RusTia 5]

Thank you all very much for the insight so far. The model number is 73402 and the serial begins with 79.

Sounds like the fuel issue can be resolved with new fuel lines, filter, and electric pump.

I did not think the starting issue would be the seat switch because the dash light works properly based on my position in or out of the seat.

The clutch pedal light on the dash also works properly so I did not think there was an issue with a switch there.  The PTO is disengaged, but I did not think about the switch here. The dash light is not illuminated when I turn the key which makes me think it is working, but I have not tested tried starting with the PTO engaged to see if the light comes on.

Would it be possible for any of the safety switches to be faulty but still read correctly on the dash?

I think I will start with a thorough cleaning and checking wires/connections. We live in the middle of crop fields with a fair bit of wind so the tractor is pummeled with dust when uncovered. I know there is a lot of dust build up in every nook and cranny. I was going to start with compressed air to dislodge most of it. Any other recommendations for cleaning the hard to reach places? Would hosing it down be a bad idea?

We also have a pretty strong field mice population so I would not be surprised if the wiring was targeted by mice at some point. I haven’t noticed any damage to wiring, but my visual inspection of the wiring has been limited to what I can see easily.

[gwest_ca-(File Mod) 11,095]

These wiring diagrams may help. Each major circuit has it's own diagram.

Garry

[953 nut 55,767]

53 minutes ago, RusTia said:

possible for any of the safety switches to be faulty but still read correctly on the dash?

 

I think I will start with a thorough cleaning and checking wires/connections.

I don't have any  as new as yours but am aware that the newer ones also have a few relays in the wiring that could be a potential problem. I suspect that the relays would be interchangeable so you could confirm that one is functioning properly and then move it around to other functions or use that socket as a test station for other relays. I have done this with later model cars. Check over the wiring diagram and you may be able to compare it to your results.

Hope this helps.

[RusTia 5]

So I had a chance to dig in a little bit this morning. I tested the PTO, Seat, and Clutch pedal switches and they are all functioning correctly. All connections are tight, and I have cleaned them the best I could. I didn't check either of the relays yet, but wanted to post some pics of one thing I uncovered that may be contributing to the problem. I decided it would be a good time to clean as much of the engine as I could and when I pulled off the flywheel cover, I found a tenant that had been toasted. He had a chance to chew through about 90% of the spark plug wire and just through the insulation on the starter wire before he expired. Before I look at the relays, is it possible that this is causing the no power at ignition? 

 

[SylvanLakeWH 25,926]

Me thinks you found the culprit.

 

New wires and recheck all the connections.

 

I did not see in your posts that you checked all the fuses - double check them as well...

[953 nut 55,767]

3 hours ago, RusTia said:

is it possible that this is causing the no power at ignition? 

            

[RusTia 5]

I guess I feel a little better then. I was afraid that the ignition coil being at the end of the circuit would not explain why there was no power to the starter. Once I replace some parts, I will report back. 

 

 

4 hours ago, SylvanLakeWH said:

Me thinks you found the culprit.

 

New wires and recheck all the connections.

 

I did not see in your posts that you checked all the fuses - double check them as well...

 

 

 

I forgot to respond to the initial suggestion, but I did check all fuses and they are all still good. 

 

 

 

[WH nut 553]

The critter damage shown will not cause a no crank condition. You need a volt meter to start with. A test light will work but wont show voltage. Start with ignition switch to make sure you have 12v in start position. If that's good move to the clutch switch. Make sure you have 12v in and out with clutch depressed. If good move to the PTO switch, 12v in and out with PTO disengaged. If good move to starter solenoid. 12v on small terminal. If that's good see if you have 12v one both sides of the large terminal. All these test are done with key in the start position. If any of the test fail then stop and repair before you go any farther.

[RusTia 5]

After a thorough cleaning and checking and re-checking connections, I hooked the battery back up and turned the key to test for voltage on each side of the switches. To my surprise, the starter engaged and and the engine cranked. I don't know where the problem was, but cleaning and securing the connections did the trick. I still have the fuel issue to tackle along with replacing the spark plug wire, but I should be in the clear. 

 

Thank you all for the support. 

[Sarge 3,463]

The main rule on electrical connections is "bright and tight" - if they are not both they can fail at the worst time . For ring terminals , use internal tooth lock washers to help keep contact and dielectric grease , for battery clamp connections either dielectric grease / non-oxidation coatings or even Fluid Film works well . Don't forget to inspect the wire end of things either - green or discolored wire is a sign of serious corrosion , which leads to increased amperage draw and lack of current capacity . When in doubt , replace it ...

Sarge

[RusTia 5]

Just wanted to thank everyone again for the help. I installed an electric fuel pump (NAPA 6101051) and replaced the fuel line. I also didn't want to mess with trying to replace the spark plug wire only, so I replaced the ignition coil. This part took two weeks to ship, but I received it early this week. Once everything was back together, my 314-8 GT fired right up and runs great.