Coils breaking down under high RPM

[Oliver880]

I have an 880 oliver that can turn some good rpms 3000-4000. The problem is that this tractor has been popping coils where they overheat and breakdown. I have tried multiple makes and same problem when the tractor pulls an open class and is allowed to wind up, pop instant power loss.

I am not running any MSD box or special ign. Still using points, 12V system and generator.

Anyone have any ideas, I beginning to get frustrated. This tractor has been pulling for many years and then all at once this occurred.

 

[andrew hegeman]

have you tried the accel super coil with electronic ignition? its the huge yellow one at the parts store. we"ve ran one for years up around 5000rpms with no trouble

 

[Anonymous-0]

are you running a balasted coil? if not maybe need to put a resistor on hot side,to much voltage for coil.is it burning points? one sure indicator of to much voltage.if that is case new points an condinsor,an balasted coil,need to request that type of coil. dan

 

[504]

Sounds like you are running 12V to the coil, you need a resistor.

 

[ericsegaline]

If you are running hi rpm with stock point they may be floating i had this problem with our alci tractor i doubled up the points spring and fixed the problem

 

[WI Walkin Boss]

Get rid of the points,put in eletronic ignition and put in a super coil.

 

[chucksoliver77]

Oliver880, my 77 turns 3800 rpm at every pull with no problem. i had dennys, [i know] do my distributor, change it to electronic and do the advance weights and one of their coils about 20 years ago. are you sure your engine is not detonating? what kind of fuel do you use? just my 2 cents, chuck

 

[WesternPa Puller]

Thanks for the input so far:

The coil is internal regulated I have also tried adding an additional resister (external) thinking that was the problem. No help. Also, it seem to require a load on the engine. I can run around the yard or down the road in at full throttle ALL day.

I doubt it the points floating as we have been using this tractor at this high RPM for many, many, many years without any problems but its a good thought. Also its not a consistent problem, IE at xxxx rpm it cases the trouble, tractor may make 1 or 2 pulls fine then the 3rd POP, or maybe the 4th, etc.... Just recently this coil ordeal started and they get so hot I can't hold my hand to it, and actually had one pop and cook the oil out.

Just wondering if anyone has ever heard of such a thing, cheaply made coils from across the pond? Source of voltage backing into the coil? Grasping at straws...I know but lots of good folks here who might have an ideal or too!

 

[Anonymous-0]

Your points aren't floating @ 4K. Get you a bosch blue coil. They will not break down. Are you sure your valve springs aren't floating?

 

[buickanddeere]

What is the voltage across the coil primary terminals when the points are closed and ignition switch is on?
How many amps through the coil primary circuit?
What is a new coil's primary resistance ?

 

[RandyB(MI)]

Valve springs floating doesn't cause a coil to get hot and boil the oil out. Neither does point bounce. He's running too much voltage to the coil. EI will not change that. First pull starts out with stone cold coil , second one, coil is still hot from 1st , thirs pull , everything is hot to start out with and only gets hotter , hense the "POP". It's always the simple things first , save your money , Jegs doesn't need any more.

 

[RandyB(MI)]

Also forgot to ask. Where is the coil located? Heat kills.