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hym123

hh120 ignition problems

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got my c120 started yesterday after hours of work than stalled again got restarted as i stated in my post c120 engines, had lot of problems with jets governor cable adjustments and such could not get running so i checked for spark had non go figure when it rains it poors :snooty: So now i guess i have to test for bad grounds ,magnito gap, bad coil or what ever i had a battery charger on the tractor not sure if i left the key in the on position i read that that could fry coil or the solid state magneto is this true? fist i don't uderstand when they tell you in the manual when testing the stator coil for resistance why the stator and magneto is bad or am i uderstanding wrong what is bad the stator or the solid state magneto i found a solid state ignition coil magneto coil on ebay they want $ 199.00 or more what any help would be great thought i had the tractor running mint than this happened

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c120 should not have a magneto. It should have points. do you have a small cover on the front right lower part of the ignition? Also is there a large black coil on the front upper left of the engine, these are two things to look for if you have point ignition.

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scott, from his other posts on this tractor, it has a techy, wasnt sure if you knew that or not.

post-6425-0-62617100-1330381759_thumb.jpg

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c120 should not have a magneto. It should have points. do you have a small cover on the front right lower part of the ignition? Also is there a large black coil on the front upper left of the engine, these are two things to look for if you have point ignition.

No mine has solid state ignition a large pack above flywheel and a charging coil #610761 a under fly wheel very hard to find and expensive

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i don't uderstand when they tell you in the manual when testing the stator coil for resistance why the stator and magneto is bad or am i uderstanding wrong what is bad the stator or the solid state magneto

Here is an X-ray view of what components are inside the Tecky SSI unt.

TechSSIModuleinnerslabeled.jpg

The CHARGE COIL you refer to and called out in the service manual as a possible source of problems is under located the flywheel.

techSSIstatorlabeled.gif

basically, the charge coil is excited by the magnets on the flywheel and sends pulses up to the SSI unit. SSI units charges up the capacitor in the unit and a pickup coil triggers off the long and short pins on the flywheel. The trigger pulses is recieved by the transistor inside the SSI unit and dupmps the capacitor charge into the coil primary - whiich of course - dumps energy into the coil secondary and ZAP - a spark.

SSISystemoverview.jpg

I sent you email with more detail that might bore most folks.

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i don't uderstand when they tell you in the manual when testing the stator coil for resistance why the stator and magneto is bad or am i uderstanding wrong what is bad the stator or the solid state magneto

Here is an X-ray view of what components are inside the Tecky SSI unt.

TechSSIModuleinnerslabeled.jpg

The CHARGE COIL you refer to and called out in the service manual as a possible source of problems is under located the flywheel.

techSSIstatorlabeled.gif

basically, the charge coil is excited by the magnets on the flywheel and sends pulses up to the SSI unit. SSI units charges up the capacitor in the unit and a pickup coil triggers off the long and short pins on the flywheel. The trigger pulses is recieved by the transistor inside the SSI unit and dupmps the capacitor charge into the coil primary - whiich of course - dumps energy into the coil secondary and ZAP - a spark. I sent you email with more detail that might bore most folks.

Can i test the wheel horse switch it has five prongs and i have the scematic on it the kill switch wire could be bad when the motor want to be shut down what does the kill wire do ? does it become disconected or doed it get grounded to kill the motor ? if it gets disconected to kill the motor can i check switch for being bad by bypassing it and conect it directly to ground?

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scott, from his other posts on this tractor, it has a techy, wasnt sure if you knew that or not.

post-6425-0-62617100-1330381759_thumb.jpg

:banghead: :banghead: :banghead: I should of none that, techys are not cheep for the coils

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i don't uderstand when they tell you in the manual when testing the stator coil for resistance why the stator and magneto is bad or am i uderstanding wrong what is bad the stator or the solid state magneto

Here is an X-ray view of what components are inside the Tecky SSI unt.

TechSSIModuleinnerslabeled.jpg

The CHARGE COIL you refer to and called out in the service manual as a possible source of problems is under located the flywheel.

techSSIstatorlabeled.gif

basically, the charge coil is excited by the magnets on the flywheel and sends pulses up to the SSI unit. SSI units charges up the capacitor in the unit and a pickup coil triggers off the long and short pins on the flywheel. The trigger pulses is recieved by the transistor inside the SSI unit and dupmps the capacitor charge into the coil primary - whiich of course - dumps energy into the coil secondary and ZAP - a spark. I sent you email with more detail that might bore most folks.

Can i test the wheel horse switch it has five prongs and i have the scematic on it the kill switch wire could be bad when the motor want to be shut down what does the kill wire do ? does it become disconected or doed it get grounded to kill the motor ? if it gets disconected to kill the motor can i check switch for being bad by bypassing it and conect it directly to ground?

The proper "WH switch" as you say should GROUND the kill wire from the charge coil under the flywheel. Grounding this wire prevents and charge pulses from reaching the charge terminal on the SSI unit - no voltage to the SSI - no spark from the SSI.

If you disconnect the kill wire from the switch, you eliminate that one possible problem. Unfortunately, on this system, there are many more possibilities. The only 2 "cheap" ones I know are the kill wire malfunction and a bad (corroded) connection at the spark plug boot in the boot on the spark wire.

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make that 3 cheap fixes

the third one would be to set the proper gap from the SSI unit pickup to the long pin

0.006 to 0.010 if I recall properly. I would set it a little toward the 0.006 side myself

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i don't uderstand when they tell you in the manual when testing the stator coil for resistance why the stator and magneto is bad or am i uderstanding wrong what is bad the stator or the solid state magneto

Here is an X-ray view of what components are inside the Tecky SSI unt.

TechSSIModuleinnerslabeled.jpg

The CHARGE COIL you refer to and called out in the service manual as a possible source of problems is under located the flywheel.

techSSIstatorlabeled.gif

basically, the charge coil is excited by the magnets on the flywheel and sends pulses up to the SSI unit. SSI units charges up the capacitor in the unit and a pickup coil triggers off the long and short pins on the flywheel. The trigger pulses is recieved by the transistor inside the SSI unit and dupmps the capacitor charge into the coil primary - whiich of course - dumps energy into the coil secondary and ZAP - a spark. I sent you email with more detail that might bore most folks.

Can i test the wheel horse switch it has five prongs and i have the scematic on it the kill switch wire could be bad when the motor want to be shut down what does the kill wire do ? does it become disconected or doed it get grounded to kill the motor ? if it gets disconected to kill the motor can i check switch for being bad by bypassing it and conect it directly to ground?

The proper "WH switch" as you say should GROUND the kill wire from the charge coil under the flywheel. Grounding this wire prevents and charge pulses from reaching the charge terminal on the SSI unit - no voltage to the SSI - no spark from the SSI.

If you disconnect the kill wire from the switch, you eliminate that one possible problem. Unfortunately, on this system, there are many more possibilities. The only 2 "cheap" ones I know are the kill wire malfunction and a bad (corroded) connection at the spark plug boot in the boot on the spark wire.

Ya I took flywheel off cleane inspected everything from plug wires bad grounds ,wired are very old also put new plug Is the kill wiregreen in color?

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make that 3 cheap fixes

the third one would be to set the proper gap from the SSI unit pickup to the long pin

0.006 to 0.010 if I recall properly. I would set it a little toward the 0.006 side myself

Ya i did that too the specs are right plus why would i have spark have tractor running than it would not start than all of a sudden it started than i could not get it running agin thought it was my new rebuilding of the carb and my adjustments than i checked again for spark had nothing,, when i first started this project i had great spark so i rebuilt carb seems that maybe i have had intermitent spark issues from the start

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color is green in my diagram

on the real stator, i recall all the wires were black

2 wires off the stator should be thicker than the rest - they are the charge wires to the regulator

one of the remaining wires should have a 90 degree push on terminal - that is the charge coil wire to the SSI unit

the remaining wire (probably going to the same connector shell as the regulator charge wires) is the kill wire

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make that 3 cheap fixes

the third one would be to set the proper gap from the SSI unit pickup to the long pin

0.006 to 0.010 if I recall properly. I would set it a little toward the 0.006 side myself

Ya i did that too the specs are right plus why would i have spark have tractor running than it would not start than all of a sudden it started than i could not get it running agin thought it was my new rebuilding of the carb and my adjustments than i checked again for spark had nothing,, when i first started this project i had great spark so i rebuilt carb seems that maybe i have had intermitent spark issues from the start

remember you are dealing with 30 - 40 year old electronics which have lived in a very high vibration / large temperature swing environment. There is a capacitior (condensor) permanently epoxied into the SSI unit. These suffer greatly just from age and can become very intermittent in operation. Some units will fail with a consistently weak spark, others spark normally for a few seconds then die. This is all related to a dried up old capacitor inside the SSI unit (the big silver / rusty colored "barrel" with the ground strap on it - in the pic below).

TechSSIModule112_rs640.jpg

On a points based system you swap out a $5 condensor. On the SSI unit, you pay $199 for another 40YEAR OLD REPLACMENT UNIT. That is why the email I sent to you describes a method to use modern auto ignition parts to build a reliable low cost replacement. It is not OEM in look, but inexpensive to retrofit.

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color is green in my diagram

on the real stator, i recall all the wires were black

2 wires off the stator should be thicker than the rest - they are the charge wires to the regulator

one of the remaining wires should have a 90 degree push on terminal - that is the charge coil wire to the SSI unit

the remaining wire (probably going to the same connector shell as the regulator charge wires) is the kill wire

Ya ok thanks i will try that first reason i thinking it might be switch is i have no key and have used a screw driver to start it for years and the hole is really worn out not sure if that might have anything tho do with it plus i now how hard this stuff is gard to find i have found the part under flywheel on line for about fifty dollors some new and some used very hesitant to by used though

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color is green in my diagram

on the real stator, i recall all the wires were black

2 wires off the stator should be thicker than the rest - they are the charge wires to the regulator

one of the remaining wires should have a 90 degree push on terminal - that is the charge coil wire to the SSI unit

the remaining wire (probably going to the same connector shell as the regulator charge wires) is the kill wire

Ya ok thanks i will try that first reason i thinking it might be switch is i have no key and have used a screw driver to start it for years and the hole is really worn out not sure if that might have anything tho do with it plus i now how hard this stuff is gard to find i have found the part under flywheel on line for about fifty dollors some new and some used very hesitant to by used though

I joins that other site were is the modification located in that site

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http://saveoldiron.47.forumer.com/raider-10-wont-start-t2184454.html

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What is eds link i see in the post from soi you gave me you said he will reconfigure my old ignition unit and,you said to matt that he is ressonable what does he do ? take the mold off the back? and put a new wounded coil in it?

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Ed will dig out some of the epoxy on the back of your old SSI unit and fish for the wires from the coil. He brings new pickup wires out of the body of the SSI unit. YOU WILL STILL NEED TO BUY THE WELLS IGNITION BOX, AND A STANDARD 12VOLT IGNITION COIL. Of course you wil need to connect wires between all the components.

There is a second site I have listed in the post from another source for an alternative system. I believe the 2nd site requires a functional charge coil in the flywheel - which you may not have.

Matt and I are just going thru a process of winding custom coils that will be electrically identical to the coils in the SSI units. There are some folks who have used crank sensors from Mustangs and Subaru's with success. If you can find a pickup that PHYSICALLY fits over the flywheel area, chances are it will work without any issues.

Let me put together a "total picture" image for you later today. The process sounds a lot more complex than it actually is to accomplish.

I have a few inches of snow I need to get off the driveway before it gets too heavy for the thrower. Be back later tonight. In the meantime, peel back the spark plug boot and check to make sure the wire is still connected to the plug clip, the ones I have looked at had corroded away. Remember - you are dealing with 30+ year old electronics and wiring,

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Ed will dig out some of the epoxy on the back of your old SSI unit and fish for the wires from the coil. He brings new pickup wires out of the body of the SSI unit. YOU WILL STILL NEED TO BUY THE WELLS IGNITION BOX, AND A STANDARD 12VOLT IGNITION COIL. Of course you wil need to connect wires between all the components.

There is a second site I have listed in the post from another source for an alternative system. I believe the 2nd site requires a functional charge coil in the flywheel - which you may not have.

Matt and I are just going thru a process of winding custom coils that will be electrically identical to the coils in the SSI units. There are some folks who have used crank sensors from Mustangs and Subaru's with success. If you can find a pickup that PHYSICALLY fits over the flywheel area, chances are it will work without any issues.

Let me put together a "total picture" image for you later today. The process sounds a lot more complex than it actually is to accomplish.

I have a few inches of snow I need to get off the driveway before it gets too heavy for the thrower. Be back later tonight. In the meantime, peel back the spark plug boot and check to make sure the wire is still connected to the plug clip, the ones I have looked at had corroded away. Remember - you are dealing with 30+ year old electronics and wiring,

Ya that was the site i was looking at last night what about the sewing spool set up with a bolt and bracket if i do eather of his set ups what do i do with the unit under theflywheel

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Ed will dig out some of the epoxy on the back of your old SSI unit and fish for the wires from the coil. He brings new pickup wires out of the body of the SSI unit. YOU WILL STILL NEED TO BUY THE WELLS IGNITION BOX, AND A STANDARD 12VOLT IGNITION COIL. Of course you wil need to connect wires between all the components.

There is a second site I have listed in the post from another source for an alternative system. I believe the 2nd site requires a functional charge coil in the flywheel - which you may not have.

Matt and I are just going thru a process of winding custom coils that will be electrically identical to the coils in the SSI units. There are some folks who have used crank sensors from Mustangs and Subaru's with success. If you can find a pickup that PHYSICALLY fits over the flywheel area, chances are it will work without any issues.

Let me put together a "total picture" image for you later today. The process sounds a lot more complex than it actually is to accomplish.

I have a few inches of snow I need to get off the driveway before it gets too heavy for the thrower. Be back later tonight. In the meantime, peel back the spark plug boot and check to make sure the wire is still connected to the plug clip, the ones I have looked at had corroded away. Remember - you are dealing with 30+ year old electronics and wiring,

Ya that was the site i was looking at last night what about the sewing spool set up with a bolt and bracket if i do eather of his set ups what do i do with the unit under theflywheel

Iv been looking at eds site im a little confused if i use the pre made unit from overnight solutions my charging coil 610748 has to be good? if so i looked at his site he shows testing the unit he shows the 20 amp unit should show 137 ohms resistance what about the 10 amp unit thanks Eric

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Iv been looking at eds site im a little confused if i use the pre made unit from overnight solutions my charging coil 610748 has to be good? if so i looked at his site he shows testing the unit he shows the 20 amp unit should show 137 ohms resistance what about the 10 amp unit thanks Eric

It is a little confusing since there are several types of Tecumseh SSI variations. Don't confuse the "battery charger" windings on the stator with the "charge coil" winding. These are two physically and electrically separate coils on the same stator. The charge coil winding is a single pole on the stator as opposed to the many battery charge windings. If you look closely at the stator, the battery windings will be thicker 14 gauge wiring. The charge coil wires are about 28 - 30 AWG. This one charge coil winding is meant to produce high voltage at a very low current. The thicker battery windings are meant to produce low voltage but high current -exactly opposite in function and hence opposite in looks also.

The 137 ohms reading is used to check the winding of the CHARGE COIL has not opened or shorted. If you get an infinite reading, the charge coil is open and defective. A reading near 0 ohms means the charge coil is shorted and defective. In either case the options from Overnight solutions will not work - you need a functioning charge coil for those updates.

The update outlined at SOI U does not require a functioning charge coil (like needed for Overnight Solutions) or a modified SSI pickup coil (as described on Ed's website). The custom wound coil (or the Mustang / Subaru pickups) eliminates the need to modify the SSI unit. Use of the Wells CR109 igniter unit with a standard 12 volt ignition coil eliminates the need for any functional Tecumseh ignition parts

.

This pic shows how the Wells unit would be wired. The style of pickup you choose will dictate what type of mounting bracket has to be fabbed for the pickup.

SSIsuboverview-1.jpg

It is confusing. I'm sure there will be more questions. It seems you need to decide which route you want to take, and that may take more discussion to allow you to fully understand all the options available to you.

Check your current charge coil resistance. Overnight solutions may work for you and you will get to retain the original "look" of the ignition system. That is more important to some folks than $$$ or effort involved in a conversion.

Eric, this type of conversion is certainly not new or "hot off the presses". The Wells box is 1980's Dodge truck technology. The fun begins when folks start mixing and matching Dodge ignition boxes with Subaru pickups, etc. Make no mistake; many folks here may have already accomplished this update to their engines. Hopefully they will chime in with additional success stories to give you the confidence to take on your update. I'll be out all day today - checking back in later tonight.

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Save_old_iron is it okay if we refer to you as an ignition guru ??

You betcha - call me what you like

Just don't call me late for dinner !

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Iv been looking at eds site im a little confused if i use the pre made unit from overnight solutions my charging coil 610748 has to be good? if so i looked at his site he shows testing the unit he shows the 20 amp unit should show 137 ohms resistance what about the 10 amp unit thanks Eric

It is a little confusing since there are several types of Tecumseh SSI variations. Don't confuse the "battery charger" windings on the stator with the "charge coil" winding. These are two physically and electrically separate coils on the same stator. The charge coil winding is a single pole on the stator as opposed to the many battery charge windings. If you look closely at the stator, the battery windings will be thicker 14 gauge wiring. The charge coil wires are about 28 - 30 AWG. This one charge coil winding is meant to produce high voltage at a very low current. The thicker battery windings are meant to produce low voltage but high current -exactly opposite in function and hence opposite in looks also.

The 137 ohms reading is used to check the winding of the CHARGE COIL has not opened or shorted. If you get an infinite reading, the charge coil is open and defective. A reading near 0 ohms means the charge coil is shorted and defective. In either case the options from Overnight solutions will not work - you need a functioning charge coil for those updates.

The update outlined at SOI U does not require a functioning charge coil (like needed for Overnight Solutions) or a modified SSI pickup coil (as described on Ed's website). The custom wound coil (or the Mustang / Subaru pickups) eliminates the need to modify the SSI unit. Use of the Wells CR109 igniter unit with a standard 12 volt ignition coil eliminates the need for any functional Tecumseh ignition parts

.

This pic shows how the Wells unit would be wired. The style of pickup you choose will dictate what type of mounting bracket has to be fabbed for the pickup.

SSIsuboverview-1.jpg

It is confusing. I'm sure there will be more questions. It seems you need to decide which route you want to take, and that may take more discussion to allow you to fully understand all the options available to you.

Check your current charge coil resistance. Overnight solutions may work for you and you will get to retain the original "look" of the ignition system. That is more important to some folks than $$$ or effort involved in a conversion.

Eric, this type of conversion is certainly not new or "hot off the presses". The Wells box is 1980's Dodge truck technology. The fun begins when folks start mixing and matching Dodge ignition boxes with Subaru pickups, etc. Make no mistake; many folks here may have already accomplished this update to their engines. Hopefully they will chime in with additional success stories to give you the confidence to take on your update. I'll be out all day today - checking back in later tonight.

I understand i don't mind using the cr 109 but i like the original look .If i test both windings on the stator than i can use the overnight solutions correct?.How do i test both wires, Do i Need to do an open test and a tickle test? to see if the two windings on the stator is good or bad? If bad i don't mind doing the mod he shows in the molded ssi unit mine is model number 610748 10 amp unit,my father is an electronic enginer he is still in fla. lucky him were still up here in ct. freezing has not been bad winter not like years past i'm sure you know living in Ny state when he gets home in a week or so i will run all things by him let me know about the questions i asked at least i can get a head start getting parts depending on what set up i will use thanks for all your help and time Eric L.

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