Can timing be off?

[abbott295]

I have a Husqvarna 128CD trimmer that has spark and gets gas but doesn't fire at all. Spark is observed with the plug out and grounded to the engine. I have put gas in the carb and even sprayed a little ether and can't get it to fire. When I brought it home from cleaning out a storage container at work, it fired and ran, but only with choke on. Maybe I couldn't get it to restart then. I left it for a while (weeks) and now it doesn't start at all. I don't have a compression tester or a spark tester to see if it sparks with the plug installed. Or if I have them, I can't find them. Any thoughts on this anyone?

This was probably bought new and used around a small townhome development under construction several times. I don't know how much or how hard it was used. There was also another trimmer of a different brand that had been left also. With a little carb adjustment it runs good but the trimmer head has the attachment bolt broken off.

Thanks in advance.

 

[cuinrearview]

Your muffler might be clogged, you may not be making compression, or your timing might be off.

 

[abbott295]

Okay, I can check the muffler easy enough and I guess I can put a thumb over the spark plug hole to get a feel for compression ( but it was running) but how can I check timing? Find top dead center, then how are the magnets on the flywheel supposed to line up with the coil?

Thanks

 

[stihl86]

Usually the magnets will be ABOUT 3/4's past the laminations at TDC
Best way, if your concerned, is pull the flywheel and check key.
Does that thing have a timing chip in the ign module?
If so, they can fail and that will drive you insane.
You can hook up a timing light to check that.
Same way you would hook one up on a vehicle.
Same process
But before you do that, remove the muffler and check the cylinder/piston.
Leave the compression tester in the box.

 

[abbott295]

I have pulled both the muffler and the carb and the piston is good. I will have to dig up a timing light. I don't know if there is a timing chip in the ignition module, or even if there is an ignition module. It is supposed to have a coil. Does that tell us anything?

Have a 128LD that my son has had in storage for about two years; I just pulled it out and used it. It runs good. I can try swapping parts to see what gets the CD going. Carb might be first because it is about the easiest. Then what?

The CD (that doesn't start ) is from 2013 according to the EPA sticker and the LD is from 2009.

 

[abbott295]

I have put the carb from the good running 128LD on the 128CD and it will sputter a little bit. That doesn't seem to be the solution. I'll try swapping plug next.

 

[abbott295]

With the other plug, it started after a lot of sputtering and ran rough long enough for me to think I could take the choke off and it died. Sometimes while trying to start it, it would pull the cord in rather abruptly. I guess I will put things back how they were and come back to it another time. Taking them apart to compare timing will need more time than I can give it today.

 

[stihl86]

Sorry, I call the coil a module. It’s most likely a one piece ign system. I’m not all that familiar with other brand other than stihl. But most brand use an timing chip. And I’ve learned, the very hard way about the problem. You really have to eliminate everything else. If you still can’t get it to run, replace the coil / module.
But check the position of the flywheel in relation to the coil. If the magnets are just passing the coil, and the piston is at the bottom of its stroke, you have a sheared key. Don’t rule it out until you verify it.
As I said, might be easier just to look at the key.
Sometimes a few degrees is enough to cause a start problem.
Sometimes it helps to keep a log of what you do and double check it.
It’s amazing how something so basically simple can be such a mf’er to figure out.
But you’re learning that LOL.