Kohler Modification
 

Well Guys:

Monday night while working in the yard, my 1450 spit and sputtered and then died. I could not restart it. Traced the problem down to NO SPARK. Since the tractor was out in the yard, had my son drag the 1450 back to the shop for in depth analysis. Traced the problem down to a bad HV Ignition Coil.

Now this isn't a serious thing BUT this is the second time it has happened it 2 years. SO....:bigthink: I got to thinking. This coil is mounted on the RH side of the cooling fins.....right where all the heat and vibration is. I am thinking this is a harsh environment for this poor coil. There must be a better location.

:Work: So, studying the situation for a while, I decided to relocate the coil. I decided to mount the coil in the LH side of the pedestal area under the dash. No heat and less vibration. So I did it. Had to rewire the (+) ignition wire, points wire, and Spark Plug wire. Started the ole girl up and all was fine again.

:Pray:

Only time will tell if this modification will be kinder to HV Ignition Coils.

:ThumbsUp:

You could wrap coil in thin strip of rubber to help with vibration I don't think case has to be grounded. Good idea to relocate.:bigthink:

Roland
I know you have a camera, lets see some pictures

Roland...Relocating the coil could be an excellent idea but how did you handle the condenser ground/connection to the coil (-). I suspect that grounding it to the pedestal may eventually create the same ground circuit resistance problem found at the IH battery ground location....or did you bolt it to the engine and just use a looooong pigtail??

Myron

Ah Myron:

Good Question......

I ran an extra Ground Wire from the from the frame to the Condenser mounting tab.

Then of course, my 1450 is loaded up with extra grounding. :biggrin2.gif:

Roland: I suggest that you add the condenser info to your original post and put it in the Tech "fix-it" section. For folks blowing coils regularly, this could be a great solution to their problems....A photo or two for the conceptionally challenged :bigthink:would likely be helpful also.

Myron

Roland I don't know about the vibration affect on the coils and heat is never a good thing in any environment. But I mow all summer with my 1450 and it is always 100 plus degrees and the coil is the one that came with the 16 hp engine I put in the 1450 8 or 10 years ago. I have the Point saver on the engine and I blow the entire tractor clean every night before I put the tractor in the garage.

My neighbor has a 1450 I rebuilt several years ago and then he made me sell it to him. He mows all summer in the heat of the day like I do and as far as I know it has the original coil. If it failed I would have to replace it for him, you know how it goes when you sell to a neighbor or a relative.

Years ago I had some problems with coils on some of my Cubs that were not used as hard as this 1450. I was buying those coils from NAPA and they had the built in resistor. I finally bought 3 coils from Madsons and replaced the bad one I had at that time and put the two spares on the shelf where they sit today with cobwebbs on them. Maybe the trick is to always have a spare.

Most coil failures I have seen can be traced back where the user runs the tractor out of gas and forgets to turn the ignition key off. This is easy to do. Note this is not a problem with tractors that incorporate magnetos which many of us are accustom to.
If the points happen to be "closed" with the ignition switch on, this severely overheats the coil, breaking down the coil's internal wiring insulation. The failure might not be immediate, and work again intermittently once cooled.

Does your coil feel extremely hot upon failure? If so, this is a sign of compromised insulation.

I have had great luck with the Bosch Blue coil. They have been known to last under extreme conditions in VWs/Porsches, where they are subjected to considerable heat.

Working with automotive points ignition systems some years, alot of the recommendations sound okay. By far the best is relocating the coil. Many old car rebuilders, tractors too, will get the OEM coils off the engine and mount it on the rig's firewall. Anything to keep it cooler and away from mechanical damage.
'Lectrons don't care where they get jazzed up, or where they gotta go, as long as the path ain't too long and hard(resistance), to follow.
Hail, that's a great idea for my tractor.

I saw a 782 once with a KT17 that had two coils mounted to the firewall/gas tank support, one for each cylinder. Duals are about $160 to replace.

Scott

'Lectrons don't care where they get jazzed up, or where they gotta go

Dirt and grease make a pretty good conductor also. Keep that stuff clean.

Rust is a pretty good conductor also.......

UPDATE....

For those points brought up that are vaild.......

Running out of gas and leaving the key on was NOT an issue for me.

NO, the HV Ign Coil does not have to be grounded to operate correctly. Isolating the coil by surrounding it with a rubber material sounds valid.

Richard...I know and value your opinions. I know your testing and AZ environment is HOT. Michigan doesn't come close to hot summers as compared to AZ :biggrin2.gif:
I simply can not say why two of my Kohler Ign Coils had a short life. Granted the first one was the original.

IIRC, I read somewhere (Old age & CRS creeps in here) that maybe it was Engineer David Kirk commented about moving the coil to a less harsh location. I am thinking, I will give this a try also.

Roland If you got 30 plus years out of the first coil I would say that is completely reasonable. Getting less than 2 years out of the second coil is not reasonable. The question is why?

If it was anybody else that had the problem I would have asked if they had bought a coil with the resistor in it and if they had checked their voltage regulator output, but knowing you I knew you had that covered.

With the quality of stuff we buy today you may have got a coil made in China.

There is nothing wrong with moving the coil to a better location, as a matter of fact I mounted my points saver on the gas tank mount to keep it away from the extreme heat.

The way the quietlines are built with the air flow under the tin across the engine and out over the muffler it should blow the heat away enough to be able to run a coil mounted on the outside of the engine tin being the coil is mounted on a bracket holding it away from the tin.

The next time I get done mowing when it is over 100 degrees I am going to see if I can put my hand on the coil without burning it. I know if you have a bad coil it gets hot to the touch almost imediately.

R Bedell,

I won't try to one up you on heat. But here in Toledo,Oh. it is not all snow in the winter. Summertime temps with humidity give us a factor that might make your dry heat feel not as bad. But more to the point. If your parts were made by Kohler rather than for a Kohler or that would fit a Kohler, then it stands to reason that you have extreme operating conditions. And I would try as drysumpjet said, the Bosch Blue coil. It is epoxy filled rather that oil filled and might be exactly what your extreme conditions demand.

I went through 3 Kohler coils in 2 years until I replaced it with a Bosch blue and it's been on there for 3 years now. Also, I can buy the Bosch cheaper at my VW parts house that I can get a Kohler coil for.

There could have just been a bad batch of Kohler coils that got out there. I got one exchanged under warranty at least.

If the first coil lasted over 20 years, then I would think the stock location is fine. Just a bad coil on the second one that failed.

Do you guys have the part
number for the bosch coils??
Thanks Jason

67hydro,

I don't have a part number. But you can get them and some other goodies here.

http://www.kirkengines.com/

RPalmer,
Got that one saved in my favorites,I agree he has some really awesome stuff.
Jason

There is another advantage of remote mounting the coil, especially on a Quietline.

The engine's sheetmetal on a Quietline frequently cracks in the stock coil mounting area. Out of frustration to address these cracks, some of us have added a second coil bracket.

Moving the coil off the engine to save the engine's sheetmetal seems to be a great solution, thanks for the idea!

RPalmer
I'll trade your August weather in Ohio for mine in Georgia anytime.

For what it is worth, the position of the coil, upright, and not on its side, will add to the life, as it lets the oil in the coil cool the internals. See the old K-series coil mountings. Ford had this same illue on its early 60-70's v-8s. Finally the pointless ign.and transistor coils came to replace the old systems. Good luck, and try keeping the old style in the upright position.:biggrin2.gif:

I noticed when I bought the 982 15 yrs ago that the coil vibrated like crazy. It had a new coil. I mounted it on a rubber mount. No vibration and no failure. Dual coils won't help. They both fire at the same time anyhow. This ignition fires on the compression and exhaust stroke. It does not discriminate .