EZGO Workhorse Robin Engine Only One Spark to Plugs

Claud Brahman

New Member
OK guys. I have been working on the same no spark thing on a EZGO Workhorse. Some time back a couple of years, it seemed I replaced the coil and it went back to work. However, last year, it began to have an intermittent fading, which seemed to be ignition related, so I would pause and drive it again and it seemed to recover. After some time, it quit. So I put it in the shed and replaced the ignition module, then the voltage regulator, then the pulser, then the coil.

So it is difficult to test the pulser, but I ordered another and setting, the two newest ones tested same. I ran the starter and got some pulsing
on the pulser on an ohm meter. I have tested the two newest coils and they test the same and in spec. I have installed two ignition modules and have the same outcomes on each. My battery is hot at 12.8 V at the battery and 11.8 V at the top of the coil when running the starter. Each time I try to start, there is one pulse to the spark plug and then no more. When I bypass from battery to coil, I get one pulse through the spark plugs with each new circuit.

So what else. I cleaned the wires and used contact cleaner and tested resistance and find about 0.3 ohms through the wiring harness, when I get my meter pins in place. I have tested some similar size 16 ga. speaker wire and find ONLY 0.0, then 0.1 then 0.2 and so on up to about 0.4 Mili Ohms. This resistance is obviously a lot less than what might be accumulated in the crimp connectors of my little wiring harness. I am of the opinion that possibly there is enough resistance to keep the generation of current from the pulse pick-up from signaling the ignition module to open the coil circuit and hence there is only one pulse each time the coil wire is charged.

I am guessing that the pulse pickup sends a small current to the ignition module as long as the solid part of the flywheel flange is under the pulse pick-up magnet. I presume that the current holds the coil circuit open, until the flywheel flange slot rolls under the magnet and the current drops and so the ignition module closes the ground wire from the coil in order to send a spark current to the plugs. I presume this is why there is only one spark at the initial starter contact.

SOOOO...... I have some speaker wire and intend to tin the ends and make solid contacts, bypassing the 4-prong plug and connecting direct to the new pigtail that plugs into the new pulse pickup connector. At the same time, run the power directly from the relay terminal through a straight red wire to the top of the coil and then a white wire from the coil ground spade terminal to the white wire on the ignition module. This is another hope. Wish me well. My car speaker mechanic says that small wires get resistance. I hope. The Ezgo workhorse is about a 1996 model.

My wife misses her garden cart. Wish me well.

If this works, I will report. It seems that others with similar problems, ether left unsolved or did not report solution.
 

Claud Brahman

New Member
Tomd of Cartaholic said:



Manual said the pulser should Ohm from 19 to 21. Anything out of that range and its bad. They do generate a small AC signal. I really don't worry about that if you got the air gap set correct. I set mine to around .020. You can check it by spinning the engine over while meter set to ac current on lower scale. You should get a reading. They all will vary.

I will say you probably bought a cheap ignitor, coil and pulser being EZGO don't stock them anymore. I am also going to make a guess that what you did won't make your cart fire also.

The one spark is a normally a sign your ignitor is bad. I got a box full of these china ones at my shop. All bad. I check them on one of my running carts for people.

The micro switch under floor mat has been known to be bad and cause firing problems also. There is a test in manual that shows how to test it. You can bypass it if you don't know how to test it.

Its probably best to start another topic being this one is four years old and you are not the original poster. Gets confusing for anyone trying to help.
 

Coy's Carts

Member
Check the two wire connector at the pulser coil, use a spark tester and wiggle the connector while turning the engine over. I just repaired two carts with bad connectors.
 

Claud Brahman

New Member
There is some truth in that the connection is suspect. I must have had multiple problems. I removed the original pulser and replaced it with another. I tested the wires. It seemed that the connection was intermittent and a little suspicious. I had put on two igniters. I was so frustrated (and being concerned that the wiring harness might have intermittent problems) that I cut the wires from the new igniter and soldered 16 ga. speaker wire and terminals to the coil and to the two prong plug for the new pulser. I was hopeful, but no luck.

So I relented and looked until I found an advertisement that had an igniter with a part number BB1130 and the imprint "Made in Japan".
I ordered an igniter AND another pulser. When these came in they looked a bit unlike the two other of each that I had purchased and more like the original parts, although the igniter did not have the part number and came in a box saying "Made in Tiawan". Obviously, some progress, none the less. I installed the new igniter with the old wiring harness and it did not work. So I installed a new pulser.

Still it did not work.

However, I tested the original pulser and found something like 20.8 olms. The newest pulser had the exact shame shape and tested 20.8 or 21 olms. The other two pulsers tested 225 olms. So I thought I was on the right track and persisted until I wiggled the wiring and finally it worked and kicked off in neutral. So that was an improvement. So I went about reassembling the shroud and the air cleaner and so on and went to back it out of the shed and it did not work. So I tested the down-stream continuity from the four prong plug at the igniter and found the coil as almost zero (1,000s) ohms and found the circuit to the pulser open. So I wiggled the two prong to the pulser, now under the reinstalled air cleaner and seemed to cause it to work. So I backed it out of the shed.

I then had to put a tube in one of the front tires and after that got the system to running again and drove around the back yard. My wife uses this as her garden cart. The ignition seemed a bit weak and the back-up alarm sounded a bit less loud. So it was about dark. I re-parked the cart and that was last night. So I intend to re-examine. I do not think the weak performance was related to the carburation. I rather suspect a week contact at the plug at the end of the wiring harness to the Pulser. As you experienced. I will examine and suspect that I will take one of the pigtails that came with the other two pulsers and after verifying their conductivity through the existing pulser plug, cut the old plug from the wiring harness and solder in.

I suspect that the black wire has some corrosion at the connection with the pin in the Pulser fitting.

Thanks for your help.

Thus far, I am guessing that the original igniter might have failed. I do not know. The change of the coil and the change of the pulser were probably unnecessary. The other two igniters, might be workable when mated up with a pulser that tests 20.8 olms. (I do not know).
What I do know however, is that one of the new igniters did not work with one of the new pulsers (the 225 ohm one), even though it had new
pulser plug and coil terminals with new speaker wire soldered to the igniter. I also know that the parts made in Tiawan cost about three prices of the other. The others might have worked for another model or might have been defective.

When the failure started, the cart had been cutting out a little bit, like for a few feet at a time. Maybe the "run no more" condition was the result of the complete failure of continuity across the two prong plug. There is a learning curve on how to diagnose. I have had to learn the hard way and have had the cart disabled until my problem solving talents could overcome my frustration. When I am successful, I will write a little schematic protocol for how to test these things. May God bless all the people who have met this problem with such frustration.
 

Tomd

Cartaholic
I doubt there was anything wrong with your original ignitor and pulser. I have worked on these carts for 25 years and the failure rate on pulsers are almost none.
If your pulser Ohms between 19 and 21 then put it back on and set the gap to around .020.
The place you ordered the OEM ignitor is not the first place to scam someone. They show a picture of OEM and you get something else.
There is no test for the ignitor other than installing yours on a running cart. I have tested a few for people here.
Check the pins where pulser connects to make sure they haven't spread apart. Wiggle all the wires when testing for spark.
If your coil has a plus and minus stamped on it then its OEM. Aftermarket ones work but they are not as good as the OEM ones which can't be purchased now.
As I have posted several times people start throwing cheap made parts on an ignition problem and actually cause a problem.
 

John Wm Zick

Cartaholic - V.I.P.
I am a newby with a "garden kart" with a Robin engine, and a dumper. I build drag engines and cars; but this kart has me at my knees. I presume that the 2 cylinders fire at the same time. I've followed the wires to the shroud. I presume like the new cars with the "signal" coming from the crank that this is similar. Am I correct? I can't find any elec. specs on what takes place under the shroud. I found wiring diagrams that seem very "sophomoric" as there is no useful information that I can use to follow thru with a diagnosis. John Zick; Von ZICK RACING ENTERPRIZES, Winter Haven, Florida. And yes, it's hotter then the hubs of hell in the shop !!!!!
 

Tomd

Cartaholic
I am a newby with a "garden kart" with a Robin engine, and a dumper. I build drag engines and cars; but this kart has me at my knees. I presume that the 2 cylinders fire at the same time. I've followed the wires to the shroud. I presume like the new cars with the "signal" coming from the crank that this is similar. Am I correct? I can't find any elec. specs on what takes place under the shroud. I found wiring diagrams that seem very "sophomoric" as there is no useful information that I can use to follow thru with a diagnosis. John Zick; Von ZICK RACING ENTERPRIZES, Winter Haven, Florida. And yes, it's hotter then the hubs of hell in the shop !!!!!
Hey John, both plugs fire at the same time but one is just what is called waste spark as only one piston is on the compression stroke. Its actually a great set up. They use a balance shaft to keep it in balance with both of those pistons coming up at the same time. There should be an AC signal coming from the pulser under the shroud. Less than 1/2 a volt. Ohm it. 19 to 21 ohms and its good. Yours not firing ?
 

John Wm Zick

Cartaholic - V.I.P.
Thanks for your reply Hot Rod! Are you saying that each time the cylinders hit TDC that only one is firing? IE, fuel is going into one cyl. every other TDC time. Do I have to take the shroud off or will the Ohm reading go all the way around. So it only takes 1/2 volt to fire the coil? Thanks again, John Zick
 

John Wm Zick

Cartaholic - V.I.P.
TOM; is there anywhere that I can purchase a manual. Trying to find one on a search-engine is pure bogus..............
 

cartmaster

Cartaholic - V.I.P.
Engine rebuild and service manual

Both plugs fire each rotation of the engine. The cylinders although running parallel will only be on the power stroke every two revolutions so the valves allow fuel and exhaust etc at the correct time for each cylinder. Known as a wasted spark system. As Tom explained, the non firing wasted spark cylinder in each rotation has no fuel or compression so cannot ignite anything.

The pulser impedance can be read from the plug / pigtail. no need to remove the shroud. The same with checking for between .1 and .5 Volts during rotation of the crank. Make sure your meter is set to the lowest AC volt scale and look for the voltage. On an older analogue needle style meter you will just see a slight fluctuation on the needle. The pulser is just a small coil activated by an indent on the flywheel when it passes in time with the power stroke.
 

cartmaster

Cartaholic - V.I.P.
If you describe the actual problem that you have, Tom or I can point you in the right direction to diagnose. There are several short cuts to find out exactly where the issue lies with these machines. Most commonly it is a bad ground between the battery and the igniter but the igniters are known to fail particularly if a boost charger has been used for starting with a bad battery or the starter generator / voltage regulator overvolts on charging while running. These igniters do not like too much voltage applied.
 

John Wm Zick

Cartaholic - V.I.P.
I have been testing other wires that looked shaky and am now going to test the wires going into the shroud. I also have been identifying the wire color, as the schematic I have and the colors are at best a 50% match. I have both types of meters as my claim to fame is after market wiring on Hot Rods, drag cars and trailers. I cannot tell you both, as to how much I appreciate your help. So are you guys saying that the plugs are firing at EVERY rotation. I would understand; as the crank is on a 1 to 1 ratio, as apposed to the cam at 2 to 1. This has been an excellent learning experience. The problem is I'm covered up with work and as I am a 1 man band it's a pain in the butt. My Wife is a car girl and helps a lot but has a hard time following on tech. stuff like this. So when we're done with a project she can talk the talk. I am absolutely proud of her. If I can be of any help with car or lite truck questions don't be afraid to ask. If you guys get to Central Florida and need "direction" we are across the lake from Lego-land and half way between Tampa and Orlando, about 5 miles South of I - 4. Jack and Oleta in Winter Haven, Florida
 

cartmaster

Cartaholic - V.I.P.
Yes, the dual coil fires every rotation. As both Trug and I have said, although both pistons rise and fall at the same time, due to valve timing, only 1 will fire each rotation and a balance shaft smooths everything out. It sounds complicated but when you get your head around it, it's really very simple to understand. Another anomaly is the ignition wiring. Some struggle to understand why there is no power directly to the keyswitch. Again this is simple. Power comes off the permanently live side of the solenoid, through a fuse, then to the pedal switch. Then up to the ignition switch and back down to the activation coil for the same solenoid to energise crank and ignition. Therefore no keyswitch power until the pedal is pushed. I have seen people spending hours looking for power and all they needed to understand was that pushing the pedal was all that was needed. So to activate the solenoid, you need the fuse to be good, pedal switch pushed and keyswitch turned on. Note that most issues with this system are rarely on the power side, but commonly on the grounds. Usual power side issues are fuse, pedal switch, keyswitch, and solenoid going high resistance when current is drawn. Ground issues are usually found at the point between the frame and bracket where the ignition components are mounted. It is good practice to dismantle this area and clean up any rust etc to make sure the grounds are solid before looking on the power side. Many people also forget that a good ground is just as important as the power side of the circuit.
Once you have crank and power to the ignition circuit, it's a simple process to eliminate components to diagnose a no spark situation. If you have all this working and good spark, valve lash and compression will be your next place to look. Another commonly overlooked part of the puzzle.
Side note: ignition timing is not adjustable on these engines.
 

John Wm Zick

Cartaholic - V.I.P.
You are exactly correct, Cartmaster...... It took me a bit of time to follow the wiring while I was correcting the wire colors on my chart, but the lite went off when I accidentally hit the pedal. I guess by not having both cylinders firing at the same time. in some form they are balancing each other along with the mechanical balancing. So I'm down to a bad igniter probably because I was a"bad boy" and put 40 amps into the battery on several occasions for an hour or better. I just looked up a new igniter and was amazed at how many different types there were. So, I'm going out to the shop and pull it so I have it in my hand. Best regards to all, Jack & Oleta
 
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