2 Chainsaws fail to start

Ronno6 · Nov 8, 2017

TheBishop said:
Strike three I'm out.

I put some starting fluid in the plug port and tried to start it, no spit, sputter or any hit of starting.

I put some starting fluid thru the carb with the air cleaner off and tried to start it, no spit or sputter either.

I waited an hour and squirted a little mix gas into the plug port and pulled the starter, no spit or sputter. I tried squirting some mix gas down the carb and pulled the starter cord and again nothing.

Not even a spit like it wanted to start.
I pulled off the starter side and connected my reversing drill with a 1/2 inch socket and pulled the trigger. The little engine turned over dozens of times without a single spit or sputter from it.

I'm almost ready to toss them both out my barn door.

I'm beginning to believe the shop repair videos on the internet, where the guy opens up a long sitting chainsaw and does everything I've done twice, are not really true.
I have repaired four other engines this year without any issues. I replaced the carb on a Honda pressure washer. Replaced the carb on a smaller Tecumseh pressure washer. Replaced the interior governor shaft of a 5K generator and cleaned out the carb on a Troy-Bilt string trimmer. And they all run great.

These chainsaw engines have stopped me in my tracks.

I have a good spark and I have fuel but I have no fire.

What else could it be?

Have you removed the mufflers yet?

TheBishop · Nov 8, 2017

Yes, I pulled the muffler this evening and cleaned it from top to bottom. the spark screen was not clogged at all but I removed it and wire brushed it.

The engine is breathing it just does not have a heartbeat. I even added a ground wire today to the ground at the coil to the spark plug. A little wire just incase the ground at the coil is failing to make a solid contact.
With the plug in and the spark adapter tester on the tester shows a almost red spark. With the plug out and the little ground wire connected to the spark plug gives me a good purple spark.

I cannot tell if the plug is firing inside the engine.

Boobala · Nov 8, 2017

TheBishop said:
Strike three I'm out.

I put some starting fluid in the plug port and tried to start it, no spit, sputter or any hit of starting.

I put some starting fluid thru the carb with the air cleaner off and tried to start it, no spit or sputter either.

I waited an hour and squirted a little mix gas into the plug port and pulled the starter, no spit or sputter. I tried squirting some mix gas down the carb and pulled the starter cord and again nothing.

Not even a spit like it wanted to start.
I pulled off the starter side and connected my reversing drill with a 1/2 inch socket and pulled the trigger. The little engine turned over dozens of times without a single spit or sputter from it.

I'm almost ready to toss them both out my barn door.

I'm beginning to believe the shop repair videos on the internet, where the guy opens up a long sitting chainsaw and does everything I've done twice, are not really true.
I have repaired four other engines this year without any issues. I replaced the carb on a Honda pressure washer. Replaced the carb on a smaller Tecumseh pressure washer. Replaced the interior governor shaft of a 5K generator and cleaned out the carb on a Troy-Bilt string trimmer. And they all run great.

These chainsaw engines have stopped me in my tracks.

I have a good spark and I have fuel but I have no fire.

What else could it be?

Well ya got a few of us scratching heads, have you tried a NEW plug, ?? sometimes a plug will not fire under compression (if compression is there) and maybe possibly a timing issue ??

Boudreaux In Eunice La. · Nov 8, 2017

Bishop take the 30 drive my house and let me check it for you. Bring da wife so she can visit with my better half.

Call me I am up late most of the time 466 3685

Ronno6 · Nov 9, 2017

Boudreaux In Eunice La. said:
Bishop take the 30 drive my house and let me check it for you. Bring da wife so she can visit with my better half.

Call me I am up late most of the time 466 3685

And, no tellin' what he might have on the stove...........

TheBishop · Nov 9, 2017

Boobala said:
Well ya got a few of us scratching heads, have you tried a NEW plug, ?? sometimes a plug will not fire under compression (if compression is there) and maybe possibly a timing issue ??

I was expecting to get a spit or pop out of the engine during one of the four fuel tries, but nothing.

I'm on my third and last new plug. Three different new plugs that all give a good spark out of the hole.

I keep a few extra new plugs on the wall, usually about a dozen or so. It's easy to pick up one every time we go to Walmart. I usually keep 4 styles of Champion on hand. I wish there was a better brand plug that one could use as a test plug only to check for firing, then replace it with a normal plug for running.
A spark plug that would burn up if used more than a few seconds, but would fire up the fuel in the chamber better than normal plugs.

Last night I was reading up on how in some cases some spark plugs will not fire under compression or certain fuel mixtures.
Today I'm going to pull the coil and test the ground contacts and verify the condition of the coil.

Does anyone have an idea how to check a coil with either a digital or analog meter for spark values. Not just resistance, but volume or range of fire?

EngineMan · Nov 9, 2017

Put one lead of a meter on the kill wire connection and the other on the metal part of the coil, do you get a reading, if so bin it...! if no reading put one lead of the meter inside the part that takes the spark plug, and again the metal part of the coil.....what is the reading..? I will ask again....did you do a compression test and a leak down test...? not seen you give an answer in your post.

"but volume or range of fire?" I have no idea what you mean by this, coils are measured for they resistance.

Boudreaux In Eunice La. · Nov 9, 2017

Bishop here is how you check primary and secondary........

One lead to plug boot other lead to ground....... should read around 2000 ohms... That is the secondary check.....

One lead to kill tab other lead to ground.......... should read 160 to 200 depending on your coil make. That is the primary check.

If either does not show a reading then you have a open circuit and a failed coil. You have spark and a strong one so your coil is good...

I can check your compression if you want to drive 30 minutes to Eunice ~!~! We just might get them running while you are here ~!~!

Boudreaux In Eunice La. · Nov 9, 2017

Ronno you are right about the food part. You know me well enough by now ~!~!

TheBishop · Nov 9, 2017

Success!

I improved the ground by placing a small strap or wire from the nut of the coil to the base of the spark plug and it fired when I pulled the starter.

It's a good thing I had the chain off because it surprised me so much because it fired up on the first pull. I almost dropped it as the chainsaw spun around in my hand. It fired and revved up so fast I was shocked.

With a little tweaking of the screws I got the idle set and the old girl runs great. I didn't expect it to work so I was not ready.
I let it run for a few minutes to get it hot enough and went to the nearest 3" limb and it cut fine and didn't bog at all.

Tomorrow or Saturday I'll sharpen the chain and put it back in it's case.

As soon as I can I'll open up the old MAC 3516, the other chainsaw, and give it a work over.
I was just about to give up, but you guys here gives help and information so freely it makes me carry on.

I'll try a pic.

Thanks again

2 Chainsaws fail to start

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