Tecumseh HH120 not starting

[edwalsh18 2]

i just posted a new thread in wheel horse section but i figured the tech talk for starting motor should be on seperate thread so this thread could stay on topic and hopefully that can help anyone later looking up similar problem with same motor. it seems the c120 wheel horse mostly came with a kohler, or it is just more popular from my searches online.

 

ok well i just bought a c 120 and it has a hh120 tecumseh that will not start. i dont know where to start on it as i pretty much suck at anything mechanical. BUT!! i search online A LOT and from what i have seen on RED SQUARE more than any other forum is the help you guys provide seems to be just awesome! so i joined up here. i also joined to share this red tractor with you guys here.

 

first thing i did was i turned the key... nothing at all, no noise. jumped the battery and turned the key and motor turned. did not start. so i disconnected the spark plug wire from spark plug and turned key to see if there was spark jumping the gap... all i got was a click then nothing. checked the voltage and it was 13+ volts on battery/jumper. thinking i just ruined something else with it i just stopped there...

 

Any help you guys could provide will be greatly appreciated. please keep in mind that i do not have much experience at all working on motors like this. Thanks!

Edited March 7, 2014 by edwalsh18

[edwalsh18 2]

okay after doing some searching here on this site i found a link to; http://enginesandmagnets.com/id9.html

where i found;

 

Dos and Don’ts

 

1. Don’t ever crank an engine with out a grounded spark plug attached to the spark plug wire, see Figure 1-2 Spark Tester. The output voltage of the ignition increases until it is high enough to arc the plug gap. With out a spark plug attached, the voltage will continue to increase until it arcs somewhere else inside the ignition where it can do permanent damage. If the engine is running, never remove the spark plug wire to kill the engine; shut off the fuel.

 

 

so basically... i DID ruin something then just before i stopped!

so now i have to figure out what exactly i ruined and how to fix it...

Edited March 8, 2014 by edwalsh18

[Save Old Iron 1,568]

 

so i disconnected the spark plug wire from spark plug and turned key to see if there was spark jumping the gap... all i got was a click then nothing.

 

 

Although the chances are high the ignition system may have been abused before you got it, the fact the engine does not crank over would have prevented the disaster outlined in Ed's website. Since you didn't crank the engine, no charge voltage was applied to the solid state ignition unit so no high voltage had to be "consumed".

 

With any electronic high energy ignition system - car or tractor - the energy produced by igniton system must be released somehow - preferably thru the spark plug gap. If the energy becomes unable to jump across the plug gap, it starts looking for the next easiest gap to jump - and that is usually inside a 40 year old igniton module with weak and cracked insulation inside the module.

 

These modules are rarely available new from any source and if they are, a $200 - $300 price tag is not unusual.

But all is not lost - you may not need to replace a 40 year old ignition module with another $200, 40 year old used ignition module. 

There all some less expensive custom alternatives if it comes to that.

 

First step is to get the tractor cranking reliably. Trickle charge the battery overnight and try again. Electronic ignitions are sensitive to battery voltage and may not fire reliably at low battery voltage.

 

Grab a Tecky HH service manual off the internet. There will be an explaination of the solid state igntion in the manual.

Basically, it looks like this inside the magic $200 box.

 

 

 

 

 

 

Functionally, it looks like this

 

 

 

 

 

 

 

In real life, with the sealing compound removed, the insides look like this

 

 

 

 

 

I'm sure there will be many more questions as we progress. Let's get the engine cranking reliably and move on from there.

Edited March 7, 2014 by Save Old Iron

[chazm 413]

Ed here is the engine manual from RS manuals, You should down the manual for your tractor so you have a copy of the wiring diagram to help out as well

Also on my tecky hh100 ,I had issues with the starter itself ,clicking & not staying engaged, Ended up replacing it due to old age.

 

 

Edited March 7, 2014 by chazm

[Ed Kennell 41,311]

Ed, Please follow SAVE OLD IRON's instructions. He is the man...er squirrel that can solve any ignition problems.  That smoking rodent has shown me the way to get several WHs firing.

 

                                                                                                             

[Save Old Iron 1,568]

Ed, there is one item to always keep foremost on your mind while troubleshooting the Tecky electronic ignition system

 

NEVER Apply 12 volts to the charge terminal of the ignition module or any free hanging wires going to the stator assembly.

 

I have that terminal circled in the image below.

 

 

 

 

Doing so will burn out a coil of wire mounted behind the engine flywheel.

 

 

 

 

 

 

This mistake would only cost you $50 to replace. Most folks who plunge into troubleshooting older electronic ignitions will at some point become frustrated and start wiring up battery voltage to different terminals to "see what happens".

 

Resist that urge. Hopefully the previous owner has received and heeded this same advice.

 

Post when you have recharged the battery and get the tractor cranking at normal speeds.

Edited March 8, 2014 by Save Old Iron

[Save Old Iron 1,568]

A digital multimeter will be extremely helpful necessary for troubleshooting the ignition circuit.

 

Do you have one?

 

A $20 meter from Sears, Radio Shack, etc will be needed to perform testing on the igntion system components

 

 

Edited March 8, 2014 by Save Old Iron

[edwalsh18 2]

A digital multimeter will be extremely helpful necessary for troubleshooting the ignition circuit.

Do you have one?

A $20 meter from Sears, Radio Shack, etc will be needed to perform testing on the igntion system components

Yeah I have this one.

I didnt have any time to get to it today but for sure when I do I will post results. Thank you for you helping me! It is greatly appreciated.

Edited March 8, 2014 by edwalsh18

[Save Old Iron 1,568]

Ed,

 

that is good news - we can do some troubleshooting with the meter .

 

Again, concentrate on getting the engine to crank before we do ignition troubleshooting.

 

I will not be around Saturday until after 7PM.

 

Hopefully. one of the members will help out getting the cranking part of our problem out of the way.

Edited March 8, 2014 by Save Old Iron