# Weak Spark - Echo HC1500 Trimmer



## CountryBumkin (Nov 11, 2015)

My old Echo hedge Trimmer won't start this year.
I put in new fuel (50:1 mix) and replaced the plug.

I have a "spark tester" for small engines. it shows I am getting some spark but it's weak, compared to my Echo PAS-230 Weed Trimmer with same spark tester.

I removed the cover and checked the gap between coil and flywheel magnet. The gap is about .020" but its not adjustable, so not much I can do.

*Does anyone know what the coil resistance is?* Or otherwise how to test it. I can't find/buy or a shop manual so I have no specs on this.

The Echo is a model HC1500
21.22 cc with Zuma C1U carb.


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## paulr44 (Oct 14, 2008)

Does your spark tester have an LED designed to be able to view spark while running the unit, or does it have a large or adjustable gap to stress test the coil? The LED type doesn't provide a proper load test, it merely indicates there is spark, not how good. The gap-type can provide a high load test, thereby testing the coil's limits. A good test is 0.150" to 0.0180". This simulates the energy required to fire a plug under compression and load. The better ones are adjustable, and come with a chart indicating what gap presents what KV in load.

I've never seen a non-adjustable coil gap on a 2-stroke engine.

Try a little WD-40 (for lube purposes) and carb. cleaner spray or other volatile cleaner spray shot in the carb. with the throttle wide open and pull it over. If it'll fire on that prime, then the fuel delivery system (carb., manifold gaskets etc.) is the issue.


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## 30yearTech (Sep 14, 2006)

Coil air gap is adjustable on Echo hedge trimmers. Unless someone had the coil off, then the gap can't change and if it was ever working alright before, then the air gap is not likely the issue. 

Like Paul suggested, try firing it off with a prime, it could be a carburetor / fuel delivery problem and not a spark issue.


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## CountryBumkin (Nov 11, 2015)

My spark tester looks like a spark plug without a center electrode with a grnd clamp on the body. it is made for small engines. I have a similar one made for standard automobile ignitions.

I tried starting with a small shot of starting fluid too. No luck.
I know I'm getting fuel because after 20 pulls, the plug is soaking. Maybe I'm getting too much fuel (or just left the choke on too long while pulling).

Now I have fuel dripping out of the muffler when the trimmer sits on its side.

Regarding the coil gap, I loosened the two allen-head bolts and inserted a brass feeler gauge in the gap, but there was no movement of the coil (I can wiggle it - so it's loose) but there is no "slotted hole" for the coil to move in.
Anyway it is within spec (from what I've read).

I've never heard of spraying WD40 into the carb. Is this to clean it, or is it act like starting fluid?

Anyways, I took it to the Echo Dealer for repair yesterday. I gave up on it. He thinks it's the carb (without testing - just from my description and because it sat for many months).

*Last question *- At the end of the year I always dump out the fuel and then run the engine until it runs dry/stops. Is this the best way to store it until next season?


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## 30yearTech (Sep 14, 2006)

CountryBumkin said:


> Regarding the coil gap, I loosened the two allen-head bolts and inserted a brass feeler gauge in the gap, but there was no movement of the coil (I can wiggle it - so it's loose) but there is no "slotted hole" for the coil to move in.
> Anyway it is within spec (from what I've read).


The mounting points are not slotted, but the mounting hole is larger then the screw, so some adjustment is possible.



CountryBumkin said:


> I've never heard of spraying WD40 into the carb. Is this to clean it, or is it act like starting fluid?


The suggestion was for lubrication when priming with something like carb. cleaner spray.



CountryBumkin said:


> *Last question *- At the end of the year I always dump out the fuel and then run the engine until it runs dry/stops. Is this the best way to store it until next season?


It's a catch 22, sometimes this works, sometimes it doesn't. 

With the ethanol in today's fuels, the diaphragms and internal check valves in carburetors can become stiff and or distort to the point that they no longer operate properly. You can switch to the pre-mixed canned fuel and avoid some of these fuel system issues associated with ethanol laced fuel.


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## paulr44 (Oct 14, 2008)

One point of interest here, even with good spark and fuel delivery, if there's a sufficient vacuum leak or lack of compression a 2-stroke won't fire. I had an Echo grass trimmer fool me once, compression FELT fine to my highly-calibrated arm, but in the end it had some scoring in the cylinder and just wouldn't run.
A blown crankshaft seal or other massive vacuum leak affects fuel-air charge transfer, and for some odd reason ends up just wetting the plug. Have seen this a few times, not often, but it catches you off guard.
Without crankcase pressure-vacuum test equipment, often (other than visual inspection, say for wetness or slimy grime build-up) the only method for testing for a vacuum leak is to have the engine at least idle, and spray around critical points with carb. cleaner etc. We use this method all the time for units that run on the lean side, before attacking the carburetor. The symptom can be the same for a number of different "diseases."


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