No spark on trimmer

[Badad]

I have a Husqvarna trimmer that fail to start. I have no visible spark on it and when I disconnect the plug put a screwdriver in the plug cap and pull like mad I can feel there is a small spark. However not when pulling normally with the plug in the whole.<br /><br />I suspect thus the coil being faulty.<br /><br />Is there a simple way to measure IF the coil is broken before I order a new one. Like using a Fluke.<br />The coil is a really simple unit that sits outside the flywheel and get a induction from two magnetos on the flywheel. It has tow connectors and one plug cable. That's all.<br /><br />Advice please from someone with this kind of knowledge.

 

[Omega-1]

Re: No spark on trimmer

Glaston,<br />Here's something you can try to determine spark coming from your magneto. Take the spark plug out of the engine, connect it to the wire from the magneto in the usual manner, place the sparkplug where you can see the spark gap, such as in a small vise, and pull the cord. If you hear and see a good spark with normal pulling, then your coil is in good shape; if it is hardly visible and cannot be heard, you probably need a new coil. Good louck

 

[technostingray]

Re: No spark on trimmer

Like first aid said, you may need a new coil but not necessarily. Let me know if the new coil solves the problem. The doctor is waiting.

 

[Grant S]

Re: No spark on trimmer

Omega, wouldnt the body of the plug need to be earthed to the engine to get a spark?<br /><br />Glastron, I have had a similar problem with my husky but found it was a plug that needed replacing, even then the spark was hard to see.<br /> A teaspoon of twostroke down the plughole and then several pulls with the plug fitted should get a cough at least if there is anything there. A weak visual can mask the fact that the problem is fuel related.<br /><br />Just my 2c worth.

 

[Badad]

Re: No spark on trimmer

Hi all,<br />Thanks for your interest. You all have valuable advice. When I pull there is no spark. If I pull and hold the cable I can feel a weak shock. What I want to do is if possible measure the coil to be sure. A new one is about $80 and the trimmer is rather old so I'm hesitant what to do.<br /><br />If anyone has electrical expetise to tell if the coil can be measured please let me know.

 

[Omega-1]

Re: No spark on trimmer

Grant S,<br /><br />You are correct in that a ground wire would need to be placed about the body of the spark plug and connected to the engine. <br />Glastron Sweed, as far as measuring the spark produced by the magneto, you will need a high capacity voltmeter to measure it. I'm not sure of what the default voltage for your magneto should be; if you can determine that from the mfg. documents, then you could attach a high capacity voltmeter to the spark plug wire and the motor ground; crank it magneto and determine the maximum volts produced on the voltmeter, then compare this to the specifications for volts by the mfg. <br /><br />Another consideration, it the replacement part cost $80, what would a replacement for the entire timmer cost? You will need to make a value judgement, based on the useful life of the remaining parts of the trimmer, as to whether you need to spend $80 for the magneto part or replace the whole unit.