HELP!! with my Magnum M14

[Racinbob 11,077]

Some of you will recall the 1996 314-H I purchased earlier this summer. 121 hours, mint condition and never had a belt on the PTO. It was used to push snow only. You'll also recall the fits it gave me pretty much from day 1. My wife uses it to mow. It would start acting up like it was starving for fuel. I replaced every component in the fuel system and fought the original Walbro until I gave up on it and put a new IST carb on it. I installed the same electric pump that I have on my 05, a Mr Gasket 42S. Each step of the way I would think I got it but absolutely nothing changed. It was like clockwork as far as how many 'laps' she would run before it acted up again. So, for the sake of this thread, it is NOT anything associated with the fuel system. 

At this point I'm thinking ignition and heat. I haven't done anything other than a new spark plug. I know that coils can act up when they get hot. When I drove it to duplicate the issue it definitely was like it was starving for fuel but yet different. Possibly losing almost all of it's horsepower. Have any of you guys have experience with these magnum ignition modules? The service manual has a detailed section for testing the module but it's for a 'will not start' situation that maybe occurs when it gets to a certain temperature and won't show itself when the module is cool.  At this point I was frustrated with this thing fighting me all summer so I parked it in the barn, called it a few choice names and walked away thinking I'd wait until spring to attack it again. It was that or drive it into a lake. Now I'm thinking I should at least tear it down to the module now. 

 

Words of wisdom anybody? 

[ebinmaine 67,483]

Keeping in mind I'm not very familiar with the Magnums, my first thought would be to switch the coil from another one that you know runs okay? Is that a possibility?

[peter lena 8,625]

@Racinbob  nothing sarcastic , but regularly look for  , repetitive  problems to show me the way , think . electrical grounding  / corrosion , would separate  every connection , enhance with dielectric spray , also look for chafing , and break loose and clean grounding points , spray , also move those fuses around , had a similar issue , on horse , at just about the same spot on lawn , turned out to be a chassis / corrosion spot , as unit flexed , connection was lost , drove me nuts , just a thought , pete

[gwest_ca-(File Mod) 11,041]

Can you try it with the muffler removed?

or remove the muffler and shake to see if it has anything loose inside.

[953 nut 55,220]

25 minutes ago, Racinbob said:

When I drove it to duplicate the issue it definitely was like it was starving for fuel but yet different. Possibly losing almost all of it's horsepower.

      I an inclined to look at the exhaust system, could be something in there that works its way into the path not allowing enough air flow.

Since the Magnum needs no external input for ignition for testing purposes you could disconnect the wiring plug (oil level, charging, and magneto) to the engine and then start it by jumping the solenoid. This will eliminate all external inputs that could be preventing the magneto from working.

 

 

[Racinbob 11,077]

20 minutes ago, gwest_ca said:

Can you try it with the muffler removed?

or remove the muffler and shake to see if it has anything loose inside.

 

18 minutes ago, 953 nut said:

      I an inclined to look at the exhaust system, could be something in there that works its way into the path not allowing enough air flow.

Since the Magnum needs no external input for ignition for testing purposes you could disconnect the wiring plug (oil level, charging, and magneto) to the engine and then start it by jumping the solenoid. This will eliminate all external inputs that could be preventing the magneto from working.

 

You guys might be on to something. I've noticed that this thing is WAY louder than the 05 Command. I've got to head to Valpo right now but my next move is a muffler check.

Edited October 21 by Racinbob

[Handy Don 12,217]

[squonk 41,103]

Have you had the tins of this mint low hr. Magnum? Mice like to chew on the coil wire under the tins

[Racinbob 11,077]

3 hours ago, ebinmaine said:

Keeping in mind I'm not very familiar with the Magnums, my first thought would be to switch the coil from another one that you know runs okay? Is that a possibility?

 

That's a good idea Eric but not an option. It's my only Magnum.

 

1 hour ago, squonk said:

Have you had the tins of this mint low hr. Magnum? Mice like to chew on the coil wire under the tins

 

 

Another good idea Mike. I haven't but will tomorrow. Along with pulling the muffler. 

 

About 25 years ago before our move to Florida we had a class A motor home. It was only 2 years old with 14k miles when we bought it. We made a trip to Florida to visit my snowbird parents and it ran great all the way. I pulled on to a busy 2 lane highway about 5 miles from where they were and tried to accelerate as quick as a 34' motor home could when it just puked out on me. I had to take quick evasive action to get out of the way. I limped it to their place and pondered. I was thinking vapor lock because the Ford 460's had a habit of that with the motorhome chassis. I contacted a dealership down there that could lift it and then had it towed there. They said it was the fuel pump and they had to pull the tank to replace it. When we were getting ready to pay they asked if it was still under warranty. It was a 3 year 36k warranty. We were good on the miles but time was a question since we bought it used. They ran the VIN and found that we still had 10 days left. Big bill avoided. It ran fine coming back to Indiana and to a couple races that summer. Then, going to a Michigan race, it puked again. I got it into a parking lot. I was fortunate to find a guy with a big enough tow truck that would come on the weekend. He was going to take it to the nearest Ford dealership but I told him I wanted to go to Eby Ford in Wakarusa, IN. After a big towing bill it was sitting on their closed lot. I talked to the service manager Monday morning and told them the scoop. A short time later the called me. He said the baffles in the muffler had collapsed. His parts guy started pricing out the replacement parts and he said "Whoa! I know this guy. He'll go aftermarket" Which I did with a Banks Stinger system (intake and exhaust). Never had a problem again.

 

That's a long winded way of explaining why I like the exhaust idea. That motor home only had 14k on it and was 2 years old when we got it. Not much and probably short trips. The 314H was 28 years old with only 121 hours of pushing snow. Cold weather hours with the potential for lots of condensation. Could be...............

 

 

 

[Lane Ranger 10,968]

I had a 314 Magnum with a bad coil and a bad coil wire to the coil wire plug that baffled me for a while,  The coils are not too expensive but you have to remove all the from tins/motor housings .   it turned ourt a mouse must have chewed on the wiring for a while but didn't get all the way through the wires.   It was in a tight spot thought that could not easily be seen or repaired.

 

 

[Racinbob 11,077]

Went out to the little barn to do the muffler and ignition thing. The barn has a double door so I reached around it blindly to unlatch it and when I swung it open this guy was staring at me. 

 

 

I've had a bat house up for a few years and there's never been a bat in it. I've tried everything to attract them but no, they don't want the house. They want to invade the barn. 

 

 

I pulled the muffler off and it looks great. No rattles and the inside (what I can see of it) look great. 

 

 

I started to pull the shroud and, as always, I needed a tool in the garage. Rather than make trips back and forth I just drove the tractor to the garage. I got on another project so I'll do it tomorrow. 

[ebinmaine 67,483]

26 minutes ago, Racinbob said:

bat house up for a few years and there's never been a bat in it. I've tried everything to attract them but no, they don't want the house

 

Up here we're told not to paint the houses. 

(Probably shouldn't paint the bats either)

 

They're still finicky about living quarters.  

[Racinbob 11,077]

2 hours ago, ebinmaine said:

 

Up here we're told not to paint the houses. 

(Probably shouldn't paint the bats either)

 

They're still finicky about living quarters.  

 

I did a bunch of research on it and found mixed information. The pro paint edged the no paint and a dark color non toxic paint was recommended. I used a water based black stain. So far, bats in the painted house =0, bats on the unpainted barn door =1. Maybe I screwed up. 

 

 

 

[953 nut 55,220]

4 hours ago, Racinbob said:

this guy was staring at me. 

[Racinbob 11,077]

I pulled the shroud off. Looking at the bolt heads I don't think it's even been off. No mouse (or bat) nests and nothing jumps out at me as a possible cause. I'll go through the tests as outlined in the service manual this afternoon. I'm still thinking this could be a heat related issue with the coil and the cold tests won't show it. 

I'm open to any suggestions.

 

 

[bds1984 1,429]

You've completed all the tests I would have.  I went nuts trying to figure out why a C175 would operate very similar to what you described.  In my case, it was the fuel cap.  The tank couldn't vent and neither the electric pump or vacuum pulse pump could draw fuel after twenty minutes of running.  Whatever it is, I hope you can diagnose it sooner than later.

[Racinbob 11,077]

The fuel cap was the first thing I swapped. 

[Bill D 1,920]

1 hour ago, Racinbob said:

I pulled the shroud off. Looking at the bolt heads I don't think it's even been off. No mouse (or bat) nests and nothing jumps out at me as a possible cause. I'll go through the tests as outlined in the service manual this afternoon. I'm still thinking this could be a heat related issue with the coil and the cold tests won't show it. 

I'm open to any suggestions.

 

 

Any rub marks on the spark plug wire.  Could be grounding out when it gets hot enough.  

If you haven't done it yet, unplug the five pin connector to the engine and see if the problem goes away when it gets hot.  Does the low oil switch shut the engine down or just give you a light?  That could be acting up.  Is a valve sticking when it gets hot?  I'd try not to open up a low hour engine, but it may come to that.

[Racinbob 11,077]

10 minutes ago, Bill D said:

Any rub marks on the spark plug wire.  Could be grounding out when it gets hot enough.  

If you haven't done it yet, unplug the five pin connector to the engine and see if the problem goes away when it gets hot.  Does the low oil switch shut the engine down or just give you a light?  That could be acting up.  Is a valve sticking when it gets hot?  I'd try not to open up a low hour engine, but it may come to that.

 

The oil switch isn't the problem. I don't see any damaged wires. What 5 pin connector?

 

So far the only thing a bit out of kilter is the coil/magnet gap. It's supposed to be between .012-.016 and it's a snug fit for a .008. Looking at the magnets it's not rubbing at all. Could the tight gap be an issue?

[ebinmaine 67,483]

39 minutes ago, Racinbob said:

Could the tight gap be an issue?

 

 

Absolutely.  

[Racinbob 11,077]

3 hours ago, ebinmaine said:

Absolutely.  

 

I was hoping I'd hear that. I'm going to gap it properly, put the muffler back on and close things up. Then it's back to the barn for the winter. The only way to really test it is mowing and that's not happening anymore this year. 

Thanks for the suggestions guys. 

Edited October 23 by Racinbob

[Bill D 1,920]

2 hours ago, Racinbob said:

 

The oil switch isn't the problem. I don't see any damaged wires. What 5 pin connector?

 

So far the only thing a bit out of kilter is the coil/magnet gap. It's supposed to be between .012-.016 and it's a snug fit for a .008. Looking at the magnets it's not rubbing at all. Could the tight gap be an issue?

There should be a 4 or 5 pin Packard connector the has the wiring for the low oil switch the charging system and the kill wire for the magneto.  Unplug the charging rectifier and this connector.  Start the tractor and run it long enough to see if the problem goes away.  There could be a wiring issue on the tractor.  Doing this will narrow it down to the engine by eliminating the tractor wiring as the culprit.

 

Also, are the valves adjusted properly?  Could be set to tight causing issues when they get hot.

Edited October 23 by Bill D

[Racinbob 11,077]

On 10/23/2024 at 2:54 PM, Bill D said:

There should be a 4 or 5 pin Packard connector the has the wiring for the low oil switch the charging system and the kill wire for the magneto.  Unplug the charging rectifier and this connector.  Start the tractor and run it long enough to see if the problem goes away.  There could be a wiring issue on the tractor.  Doing this will narrow it down to the engine by eliminating the tractor wiring as the culprit.

Also, are the valves adjusted properly?  Could be set to tight causing issues when they get hot.

 

Ok, I know the one you're referring to. It's a 5 pin but only 4 are used (2 wires paralleled). I don't like those and this one is no exception. I'm going to take care of it tomorrow before it goes back to the barn.

There's really no way to recreate the situation without the deck on and mowing. It acts up about 20 minutes in to it. I think my wife could pinpoint just when it will happen. But it's not a kill situation. The low oil circuit, kill wire and charging system aren't the cause. But I still want to take care of that inferno Packard anyways. 

Edited October 24 by Racinbob

[953 nut 55,220]

6 hours ago, Bill D said:

Does the low oil switch shut the engine down

The low oil switch interrupts the starting signal when the oil level is low, has nothing to do with ignition.

[ohiofarmer 3,265]

my 314 had some run issues. it turmed out to need a new key switch.